Synchronization signal block transmission for network energy saving

Abstract

A method can include receiving, by a wireless device, one or more radio resource control (RRC) messages that include a synchronization signal block (SSB) periodicity value of SSBs of a first cell, one or more additional SSB periodicity values of the SSBs of the first cell, and one or more on-demand SSB periodicity values of on-demand SSBs of the first cell. The method can also include receiving a downlink control information (DCI) that includes a SSB periodicity indication for an adaptation of SSB periodicity of the first cell. The method can further include receiving, based on the DCI and via the first cell, the SSBs with a first additional SSB periodicity value indicated by the SSB periodicity indication from the SSB periodicity value and the one or more additional SSB periodicity values.

Description

TITLESynchronization Signal Block Transmission for Network Energy SavingCROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 677,788, filed July 31 ,2024, which is hereby incorporated by reference in its entirety.BRIEF DESCRIPTION OF THE DRAWINGS

[0002] Examples of several of the various embodiments of the present disclosure are described herein with reference to the drawings.

[0003] FIG. 1A and FIG. 1 B illustrate example mobile communication networks in which embodiments of the present disclosure may be implemented.

[0004] FIG. 2A and FIG. 2B respectively illustrate a New Radio (NR) user plane and control plane protocol stack.

[0005] FIG. 3 illustrates an example of services provided between protocol layers of the NR user plane protocol stack of FIG. 2A.

[0006] FIG. 4A illustrates an example downlink data flow through the NR user plane protocol stack of FIG. 2A.

[0007] FIG. 4B illustrates an example format of a MAC subheader in a MAC PDU.

[0008] FIG. 5A and FIG. 5B respectively illustrate a mapping between logical channels, transport channels, and physical channels for the downlink and uplink.

[0009] FIG. 6 is an example diagram showing RRC state transitions of a UE.

[0010] FIG. 7 illustrates an example configuration of an NR frame into which OFDM symbols are grouped.

[0011] FIG. 8 illustrates an example configuration of a slot in the time and frequency domain for an NR carrier.

[0012] FIG. 9 illustrates an example of bandwidth adaptation using three configured BWPs for an NR carrier.

[0013] FIG. 10A illustrates three carrier aggregation configurations with two component carriers.

[0014] FIG. 10B illustrates an example of how aggregated cells may be configured into one or morePUCCH groups.

[0015] FIG. 11A illustrates an example of an SS / PBCH block structure and location.

[0016] FIG. 11 B illustrates an example of CSI-RSs that are mapped in the time and frequency domains.

[0017] FIG. 12A and FIG. 12B respectively illustrate examples of three downlink and uplink beam management procedures.

[0018] FIG. 13A, FIG. 13B, and FIG. 13C respectively illustrate a four-step contention-based random access procedure, a two-step contention-free random access procedure, and another two-step random access procedure.

[0019] FIG. 14A illustrates an example of CORESET configurations for a bandwidth part.

[0020] FIG. 14B illustrates an example of a CCE-to-REG mapping for DCI transmission on a CORESET and PDCCH processing.

[0021] FIG. 15 illustrates an example of a wireless device in communication with a base station.

[0022] FIG. 16A, FIG. 16B, FIG. 16C, and FIG. 16D illustrate example structures for uplink and downlink transmission.

[0023] FIG. 17A, FIG. 17B, and FIG. 17C illustrate aspects of example embodiments according to the present disclosure.

[0024] FIG. 18A and FIG. 18B illustrate aspects of example embodiments according to the present disclosure.

[0025] FIG. 19 illustrates an aspect of an example embodiment according to the present disclosure.

[0026] FIG. 20 illustrates an aspect of an example embodiment according to the present disclosure

[0027] FIG. 21 A and FIG. 21 B illustrate aspects of example embodiments according to the present disclosure.

[0028] FIG. 22 illustrates an aspect of an example embodiment according to the present disclosure.

[0029] FIG. 23 illustrates an aspect of an example embodiment according to the present disclosure

[0030] FIG. 24A, FIG. 24B, and FIG. 24C illustrate aspects of example embodiments according to the present disclosure.

[0031] FIG. 25 illustrates an aspect of an example embodiment according to the present disclosure.

[0032] FIG. 26 illustrates an aspect of an example embodiment according to the present disclosure.

[0033] FIG. 27 illustrates an aspect of an example embodiment according to the present disclosure

[0034] FIG. 28 illustrates an aspect of an example embodiment according to the present disclosure.

[0035] FIG. 29 illustrates an aspect of an example embodiment according to the present disclosure.

[0036] FIG. 30 illustrates an aspect of an example embodiment according to the present disclosure.

[0037] FIG. 31 illustrates an aspect of an example embodiment according to the present disclosure

[0038] FIG. 32A and FIG. 32B illustrate aspects of example embodiments according to the present disclosure.

[0039] FIG. 33 illustrates an aspect of an example embodiment according to the present disclosure.

[0040] FIG. 34 illustrates an aspect of an example embodiment according to the present disclosure.

[0041] FIG. 35 illustrates an aspect of an example embodiment according to the present disclosure

[0042] FIG. 36 illustrates an aspect of an example embodiment according to the present disclosure.

[0043] FIG. 37 illustrates an aspect of an example embodiment according to the present disclosure

[0044] FIG. 38 illustrates an aspect of an example embodiment according to the present disclosure.

[0045] FIG. 39A and FIG. 39B illustrate aspects of example embodiments according to the present disclosure.

[0046] FIG. 40 illustrates an aspect of an example embodiment according to the present disclosure.

[0047] FIG. 41 illustrates an aspect of an example embodiment according to the present disclosure.

[0048] FIG. 42 illustrates an aspect of an example embodiment according to the present disclosure.

[0049] FIG. 43 illustrates an aspect of an example embodiment according to the present disclosure.

[0050] FIG. 44 illustrates an aspect of an example embodiment according to the present disclosure.

[0051] FIG. 45 illustrates an aspect of an example embodiment according to the present disclosure

[0052] FIG. 46 illustrates an aspect of an example embodiment according to the present disclosure.

[0053] FIG. 47 illustrates an aspect of an example embodiment according to the present disclosure.DETAILED DESCRIPTION

[0054] In the present disclosure, various embodiments are presented as examples of how the disclosed techniques may be implemented and / or how the disclosed techniques may be practiced in environments and scenarios. It will be apparent to persons skilled in the relevant art that various changes in form and detail can be made therein without departing from the scope. In fact, after reading the description, it will be apparent to one skilled in the relevant art how to implement alternative embodiments. The present embodiments should not be limited by any of the described exemplary embodiments. The embodiments of the present disclosure will be described with reference to the accompanying drawings. Limitations, features, and / or elements from the disclosed example embodiments may be combined to create further embodiments within the scope of the disclosure. Any figures which highlight the functionality and advantages, are presented for example purposes only. The disclosed architecture is sufficiently flexible and configurable, such that it may be utilized in ways other than that shown. For example, the actions listed in any flowchart may be re-ordered or only optionally used in some embodiments.

[0055] Embodiments may be configured to operate as needed. The disclosed mechanism may be performed when certain criteria are met, for example, in a wireless device, a base station, a radio environment, a network, a combination of the above, and / or the like. Example criteria may be based, at least in part, on for example, wireless device or network node configurations, traffic load, initial system set up, packet sizes, traffic characteristics, a combination of the above, and / or the like. When the one or more criteria are met, various example embodiments may be applied. Therefore, it may be possible to implement example embodiments that selectively implement disclosed protocols.

[0056] A base station may communicate with a mix of wireless devices. Wireless devices and / or base stations may support multiple technologies, and / or multiple releases of the same technology. Wirelessdevices may have some specific capability(ies) depending on wireless device category and / or capability(ies). When this disclosure refers to a base station communicating with a plurality of wireless devices, this disclosure may refer to a subset of the total wireless devices in a coverage area. This disclosure may refer to, for example, a plurality of wireless devices of a given LTE or 5G release with a given capability and in a given sector of the base station. The plurality of wireless devices in this disclosure may refer to a selected plurality of wireless devices, and / or a subset of total wireless devices in a coverage area which perform according to disclosed methods, and / or the like. There may be a plurality of base stations or a plurality of wireless devices in a coverage area that may not comply with the disclosed methods, for example, those wireless devices or base stations may perform based on older releases of LTE or 5G technology.

[0057] In this disclosure, "a” and “an” and similar phrases are to be interpreted as “at least one" and “one or more.” Similarly, any term that ends with the suffix “(s)” is to be interpreted as “at least one” and “one or more.” In this disclosure, the term “may” is to be interpreted as “may, for example.” In other words, the term “may” is indicative that the phrase following the term “may” is an example of one of a multitude of suitable possibilities that may, or may not, be employed by one or more of the various embodiments. The terms “comprises” and “consists of', as used herein, enumerate one or more components of the element being described. The term “comprises” is interchangeable with “includes" and does not exclude unenumerated components from being included in the element being described. By contrast, “consists of provides a complete enumeration of the one or more components of the element being described. The term “based on”, as used herein, should be interpreted as “based at least in part on” rather than, for example, “based solely on”. The term “and / or” as used herein represents any possible combination of enumerated elements. For example, “A, B, and / or C” may represent A; B; C; A and B; A and C; B and C; or A, B, and C.

[0058] If A and B are sets and every element of A is an element of B, A is called a subset of B. In this specification, only non-empty sets and subsets are considered. For example, possible subsets of B = {celH , cell2} are: {celH }, {cell2}, and {celH , cell2}. The phrase “based on” (or equally “based at least on”) is indicative that the phrase following the term “based on” is an example of one of a multitude of suitable possibilities that may, or may not, be employed to one or more of the various embodiments. The phrase “in response to” (or equally “in response at least to”) is indicative that the phrase following the phrase “in response to” is an example of one of a multitude of suitable possibilities that may, or may not, be employed to one or more of the various embodiments. The phrase “depending on” (or equally “depending at least to”) is indicative that the phrase following the phrase “depending on” is an example of one of a multitude of suitable possibilities that may, or may not, be employed to one or more of the various embodiments. The phrase “employing / using” (or equally “employing / using at least”) is indicative that the phrase following thephrase "employing / using” is an example of one of a multitude of suitable possibilities that may, or may not, be employed to one or more of the various embodiments.

[0059] The term configured may relate to the capacity of a device whether the device is in an operational or non-operational state. Configured may refer to specific settings in a device that affect or implement the operational characteristics of the device whether the device is in an operational or non-operational state. In other words, the hardware, software, firmware, registers, memory values, and / or the like may be “configured” within a device, whether the device is in an operational or nonoperational state, to provide the device with specific characteristics. Terms such as “a control message to cause in a device” may mean that a control message has parameters that may be used to configure specific characteristics or may be used to implement certain actions in the device, whether the device is in an operational or non-operational state.

[0060] In this disclosure, parameters (or equally called, fields, or Information elements: lEs) may comprise one or more information objects, and an information object may comprise one or more other objects. For example, if parameter (IE) N comprises parameter (IE) M, and parameter (IE) M comprises parameter (IE) K, and parameter (IE) K comprises parameter (information element) J. Then, for example, N comprises K, and N comprises J In an example embodiment, when one or more messages comprise a plurality of parameters, it implies that a parameter in the plurality of parameters is in at least one of the one or more messages, but does not have to be in each of the one or more messages.

[0061] Many features presented are described as being optional through the use of “may” or the use of parentheses For the sake of brevity and legibility, the present disclosure does not explicitly recite each and every permutation that may be obtained by choosing from the set of optional features. The present disclosure is to be interpreted as explicitly disclosing all such permutations. For example, a system described as having three optional features may be embodied in seven ways, namely with just one of the three possible features, with any two of the three possible features or with three of the three possible features

[0062] Many of the elements described in the disclosed embodiments may be implemented as modules. A module is defined here as an element that performs a defined function and has a defined interface to other elements. The modules described in this disclosure may be implemented in hardware, software in combination with hardware, firmware, wetware (e.g., hardware with a biological element), or a combination thereof, which may be behaviorally equivalent. For example, modules may be implemented as a software routine written in a computer language configured to be executed by a hardware machine (such as C, C++, Fortran, Java, Basic, MATLAB or the like) or a modeling / simulation program such as Simulink, Stateflow, GNU Octave, or LabVIEWMathScript. It may be possible to implement modules using physical hardware that incorporates discrete or programmable analog, digital and / or quantum hardware. Examples of programmable hardware comprise: computers, microcontrollers, microprocessors, application-specificintegrated circuits (ASICs); field programmable gate arrays (FPGAs); and complex programmable logic devices (CPLDs). Computers, microcontrollers and microprocessors are programmed using languages such as assembly, C, C++ or the like. FPGAs, ASICs and CPLDs are often programmed using hardware description languages (HDL) such as VHSIC hardware description language (VHDL) or Verilog that configure connections between internal hardware modules with lesser functionality on a programmable device. The mentioned technologies are often used in combination to achieve the result of a functional module.

[0063] FIG. 1 A illustrates an example of a mobile communication network 100 in which embodiments of the present disclosure may be implemented. The mobile communication network 100 may be, for example, a public land mobile network (PLMN) run by a network operator. As illustrated in FIG. 1A, the mobile communication network 100 includes a core network (CN) 102, a radio access network (RAN) 104, and a wireless device 106.

[0064] The CN 102 may provide the wireless device 106 with an interface to one or more data networks (DNs), such as public DNs (e.g., the Internet), private DNs, and / or intra-operator DNs. As part of the interface functionality, the CN 102 may set up end-to-end connections between the wireless device 106 and the one or more DNs, authenticate the wireless device 106, and provide charging functionality.

[0065] The RAN 104 may connect the CN 102 to the wireless device 106 through radio communications over an air interface. As part of the radio communications, the RAN 104 may provide scheduling, radio resource management, and retransmission protocols. The communication direction from the RAN 104 to the wireless device 106 over the air interface is known as the downlink and the communication direction from the wireless device 106 to the RAN 104 over the air interface is known as the uplink. Downlink transmissions may be separated from uplink transmissions using frequency division duplexing (FDD), timedivision duplexing (TDD), and / or some combination of the two duplexing techniques.

[0066] The term wireless device may be used throughout this disclosure to refer to and encompass any mobile device or fixed (non-mobile) device for which wireless communication is needed or usable. For example, a wireless device may be a telephone, smart phone, tablet, computer, laptop, sensor, meter, wearable device, Internet of Things (loT) device, vehicle roadside unit (RSU), relay node, automobile, and / or any combination thereof. The term wireless device encompasses other terminology, including user equipment (UE), user terminal (UT), access terminal (AT), mobile station, handset, wireless transmit and receive unit (WTRU), and / or wireless communication device.

[0067] The RAN 104 may include one or more base stations (not shown). The term base station may be used throughout this disclosure to refer to and encompass a Node B (associated with UMTS and / or 3G standards), an Evolved Node B (eNB, associated with E-UTRA and / or 4G standards), a remote radio head (RRH), a baseband processing unit coupled to one or more RRHs, a repeater node or relay node used toextend the coverage area of a donor node, a Next Generation Evolved Node B (ng-eNB), a Generation Node B (gNB, associated with NR and / or 5G standards), an access point (AP, associated with, for example, Wi-Fi or any other suitable wireless communication standard), and / or any combination thereof. A base station may comprise at least one gNB Central Unit (gNB-CU) and at least one a gNB Distributed Unit (gNB-DU).

[0068] A base station included in the RAN 104 may include one or more sets of antennas for communicating with the wireless device 106 over the air interface. For example, one or more of the base stations may include three sets of antennas to respectively control three cells (or sectors). The size of a cell may be determined by a range at which a receiver (e.g ., a base station receiver) can successfully receive the transmissions from a transmitter (e.g., a wireless device transmitter) operating in the cell. Together, the cells of the base stations may provide radio coverage to the wireless device 106 over a wide geographic area to support wireless device mobility.

[0069] In addition to three-sector sites, other implementations of base stations are possible. For example, one or more of the base stations in the RAN 104 may be implemented as a sectored site with more or less than three sectors. One or more of the base stations in the RAN 104 may be implemented as an access point, as a baseband processing unit coupled to several remote radio heads (RRHs), and / or as a repeater or relay node used to extend the coverage area of a donor node. A baseband processing unit coupled to RRHs may be part of a centralized or cloud RAN architecture, where the baseband processing unit may be either centralized in a pool of baseband processing units or virtualized. A repeater node may amplify and rebroadcast a radio signal received from a donor node. A relay node may perform the same / similar functions as a repeater node but may decode the radio signal received from the donor node to remove noise before amplifying and rebroadcasting the radio signal.

[0070] The RAN 104 may be deployed as a homogenous network of macrocell base stations that have similar antenna patterns and similar high-level transmit powers. The RAN 104 may be deployed as a heterogeneous network. In heterogeneous networks, small cell base stations may be used to provide small coverage areas, for example, coverage areas that overlap with the comparatively larger coverage areas provided by macrocell base stations. The small coverage areas may be provided in areas with high data traffic (or so-called “hotspots”) or in areas with weak macrocell coverage Examples of small cell base stations include, in order of decreasing coverage area, microcell base stations, picocell base stations, and femtocell base stations or home base stations.

[0071] The Third-Generation Partnership Project (3GPP) was formed in 1998 to provide global standardization of specifications for mobile communication networks similar to the mobile communication network 100 in FIG. 1A To date, 3GPP has produced specifications for three generations of mobile networks: a third generation (3G) network known as Universal Mobile Telecommunications System(UMTS), a fourth generation (4G) network known as Long-Term Evolution (LTE), and a fifth generation (5G) network known as 5G System (5GS). Embodiments of the present disclosure are described with reference to the RAN of a 3GPP 5G network, referred to as next-generation RAN (NG-RAN). Embodiments may be applicable to RANs of other mobile communication networks, such as the RAN 104 in FIG. 1A, the RANs of earlier 3G and 4G networks, and those of future networks yet to be specified (e.g., a 3GPP 6G network). NG-RAN implements 5G radio access technology known as New Radio (NR) and may be provisioned to implement 4G radio access technology or other radio access technologies, including non- 3GPP radio access technologies.

[0072] FIG. 1 B illustrates another example mobile communication network 150 in which embodiments of the present disclosure may be implemented. Mobile communication network 150 may be, for example, a PLMN run by a network operator. As illustrated in FIG. 1 B, mobile communication network 150 includes a 5G core network (5G-CN) 152, an NG-RAN 154, and UEs 156A and 156B (collectively UEs 156). These components may be implemented and operate in the same or similar manner as corresponding components described with respect to FIG. 1 A.

[0073] The 5G-CN 152 provides the UEs 156 with an interface to one or more DNs, such as public DNs (e.g., the Internet), private DNs, and / or intra-operator DNs. As part of the interface functionality, the 5G-CN 152 may set up end-to-end connections between the UEs 156 and the one or more DNs, authenticate the UEs 156, and provide charging functionality. Compared to the CN of a 3GPP 4G network, the basis of the 5G-CN 152 may be a service-based architecture. This means that the architecture of the nodes making up the 5G-CN 152 may be defined as network functions that offer services via interfaces to other network functions. The network functions of the 5G-CN 152 may be implemented in several ways, including as network elements on dedicated or shared hardware, as software instances running on dedicated or shared hardware, or as virtualized functions instantiated on a platform (e.g., a cloud-based platform).

[0074] As illustrated in FIG. 1 B, the 5G-CN 152 includes an Access and Mobility Management Function (AMF) 158A and a User Plane Function (UPF) 158B, which are shown as one component AMF / UPF 158 in FIG. 1 B for ease of illustration. The UPF 158B may serve as a gateway between the NG-RAN 154 and the one or more DNs. The UPF 158B may perform functions such as packet routing and forwarding, packet inspection and user plane policy rule enforcement, traffic usage reporting, uplink classification to support routing of traffic flows to the one or more DNs, quality of service (QoS) handling for the user plane (e.g., packet filtering, gating, uplink / downlink rate enforcement, and uplink traffic verification), downlink packet buffering, and downlink data notification triggering. The UPF 158B may serve as an anchor point for intra- / inter-Radio Access Technology (RAT) mobility, an external protocol (or packet) data unit (PDU) session point of interconnect to the one or more DNs, and / or a branching point to support a multi-homed PDUsession. The UEs 156 may be configured to receive services through a PDU session, which is a logical connection between a UE and a DN.

[0075] The AMF 158A may perform functions such as Non-Access Stratum (NAS) signaling termination, NAS signaling security, Access Stratum (AS) security control, inter-CN node signaling for mobility between 3GPP access networks, idle mode UE reachability (e.g., control and execution of paging retransmission), registration area management, intra-system and inter-system mobility support, access authentication, access authorization including checking of roaming rights, mobility management control (subscription and policies), network slicing support, and / or session management function (SMF) selection. NAS may refer to the functionality operating between a CN and a UE, and AS may refer to the functionality operating between the UE and a RAN.

[0076] The 5G-CN 152 may include one or more additional network functions that are not shown in FIG. 1 B for the sake of clarity. For example, the 5G-CN 152 may include one or more of a Session Management Function (SMF), an NR Repository Function (NRF), a Policy Control Function (PCF), a Network Exposure Function (NEF), a Unified Data Management (UDM), an Application Function (AF), and / or an Authentication Server Function (AUSF).

[0077] The NG-RAN 154 may connect the 5G-CN 152 to the UEs 156 through radio communications over the air interface. The NG-RAN 154 may include one or more gNBs, illustrated as gNB 160A and gNB 160B (collectively gNBs 160) and / or one or more ng-eNBs, illustrated as ng-eNB 162A and ng-eNB 162B (collectively ng-eNBs 162). The gNBs 160 and ng-eNBs 162 may be more generically referred to as base stations. The gNBs 160 and ng-eNBs 162 may include one or more sets of antennas for communicating with the UEs 156 over an air interface. For example, one or more of the gNBs 160 and / or one or more of the ng-eNBs 162 may include three sets of antennas to respectively control three cells (or sectors). Together, the cells of the gNBs 160 and the ng-eNBs 162 may provide radio coverage to the UEs 156 over a wide geographic area to support UE mobility.

[0078] As shown in FIG. 1 B, the gNBs 160 and / or the ng-eNBs 162 may be connected to the 5G-CN 152 by means of an NG interface and to other base stations by an Xn interface. The NG and Xn interfaces may be established using direct physical connections and / or indirect connections over an underlying transport network, such as an internet protocol (IP) transport network. The gNBs 160 and / or the ng-eNBs 162 may be connected to the UEs 156 by means of a Uu interface. For example, as illustrated in FIG. 1 B, gNB 160A may be connected to the UE 156A by means of a Uu interface. The NG, Xn, and Uu interfaces are associated with a protocol stack. The protocol stacks associated with the interfaces may be used by the network elements in FIG. 1 B to exchange data and signaling messages and may include two planes: a user plane and a control plane. The user plane may handle data of interest to a user. The control plane may handle signaling messages of interest to the network elements.

[0079] The gNBs 160 and / or the ng-eNBs 162 may be connected to one or more AMF / UPF functions of the 5G-CN 152, such as the AMF / UPF 158, by means of one or more NG interfaces. For example, the gNB 160A may be connected to the UPF 158B of the AMF / UPF 158 by means of an NG-User plane (NG-U) interface. The NG-U interface may provide delivery (e.g., non-guaranteed delivery) of user plane PDUs between the gNB 160A and the UPF 158B. The gNB 160A may be connected to the AMF 158A by means of an NG-Control plane (NG-C) interface. The NG-C interface may provide, for example, NG interface management, UE context management, UE mobility management, transport of NAS messages, paging, PDU session management, and configuration transfer and / or warning message transmission.

[0080] The gNBs 160 may provide NR user plane and control plane protocol terminations towards the UEs 156 over the Uu interface. For example, the gNB 160A may provide NR user plane and control plane protocol terminations toward the UE 156A over a Uu interface associated with a first protocol stack. The ng- eNBs 162 may provide Evolved UMTS Terrestrial Radio Access (E-UTRA) user plane and control plane protocol terminations towards the UEs 156 over a Uu interface, where E-UTRA refers to the 3GPP 4G radio-access technology. For example, the ng-eNB 162B may provide E-UTRA user plane and control plane protocol terminations towards the UE 156B over a Uu interface associated with a second protocol stack.

[0081] The 5G-CN 152 was described as being configured to handle NR and 4G radio accesses. It will be appreciated by one of ordinary skill in the art that it may be possible for NR to connect to a 4G core network in a mode known as "non-standalone operation.” In non-standalone operation, a 4G core network is used to provide (or at least support) control-plane functionality (e.g., initial access, mobility, and paging). Although only one AMF / UPF 158 is shown in FIG. 1 B, one gNB or ng-eNB may be connected to multiple AMF / UPF nodes to provide redundancy and / or to load share across the multiple AMF / UPF nodes.

[0082] As discussed, an interface (e.g., Uu, Xn, and NG interfaces) between the network elements in FIG. 1 B may be associated with a protocol stack that the network elements use to exchange data and signaling messages. A protocol stack may include two planes: a user plane and a control plane. The user plane may handle data of interest to a user, and the control plane may handle signaling messages of interest to the network elements.

[0083] FIG. 2A and FIG. 2B respectively illustrate examples of NR user plane and NR control plane protocol stacks for the Uu interface that lies between a UE 210 and a gNB 220. The protocol stacks illustrated in FIG. 2A and FIG. 2B may be the same or similar to those used for the Uu interface between, for example, the UE 156A and the gNB 160A shown in FIG. 1 B.

[0084] FIG. 2A illustrates a NR user plane protocol stack comprising five layers implemented in the UE 210 and the gNB 220. At the bottom of the protocol stack, physical layers (PHYs) 211 and 221 may provide transport services to the higher layers of the protocol stack and may correspond to layer 1 of the OpenSystems Interconnection (OS I) model. The next four protocols above PHYs 211 and 221 comprise media access control layers (MACs) 212 and 222, radio link control layers (RLCs) 213 and 223, packet data convergence protocol layers (PDCPs) 214 and 224, and service data application protocol layers (SDAPs) 215 and 225. Together, these four protocols may make up layer 2, or the data link layer, of the OSI model.

[0085] FIG. 3 illustrates an example of services provided between protocol layers of the NR user plane protocol stack. Starting from the top of FIG. 2A and FIG. 3, the SDAPs 215 and 225 may perform QoS flow handling. The UE 210 may receive services through a PDU session, which may be a logical connection between the UE 210 and a DN. The PDU session may have one or more QoS flows. A UPF of a CN (e.g., the UPF 158B) may map IP packets to the one or more QoS flows of the PDU session based on QoS requirements (e.g., in terms of delay, data rate, and / or error rate). The SDAPs 215 and 225 may perform mapping / de-mapping between the one or more QoS flows and one or more data radio bearers. The mapping / de-mapping between the QoS flows and the data radio bearers may be determined by the SDAP 225 at the gNB 220. The SDAP 215 at the UE 210 may be informed of the mapping between the QoS flows and the data radio bearers through reflective mapping or control signaling received from the gNB 220. For reflective mapping, the SDAP 225 at the gNB 220 may mark the downlink packets with a QoS flow indicator (QFI), which may be observed by the SDAP 215 at the UE 210 to determine the mapping / de-mapping between the QoS flows and the data radio bearers.

[0086] The PDCPs 214 and 224 may perform header compression / decompression to reduce the amount of data that needs to be transmitted over the air interface, ciphering / deciphering to prevent unauthorized decoding of data transmitted over the air interface, and integrity protection (to ensure control messages originate from intended sources. The PDCPs 214 and 224 may perform retransmissions of undelivered packets, in-sequence delivery and reordering of packets, and removal of packets received in duplicate due to, for example, an intra-g NB handover. The PDCPs 214 and 224 may perform packet duplication to improve the likelihood of the packet being received and, at the receiver, remove any duplicate packets. Packet duplication may be useful for services that require high reliability.

[0087] Although not shown in FIG. 3, PDCPs 214 and 224 may perform mapping / de-mapping between a split radio bearer and RLC channels in a dual connectivity scenario. Dual connectivity is a technique that allows a UE to connect to two cells or, more generally, two cell groups: a master cell group (MCG) and a secondary cell group (SCG). A split bearer is when a single radio bearer, such as one of the radio bearers provided by the PDCPs 214 and 224 as a service to the SDAPs 215 and 225, is handled by cell groups in dual connectivity. The PDCPs 214 and 224 may map / de-map the split radio bearer between RLC channels belonging to cell groups.

[0088] The RLCs 213 and 223 may perform segmentation, retransmission through Automatic Repeat Request (ARQ), and removal of duplicate data units received from MACs 212 and 222, respectively. TheRLCs 213 and 223 may support three transmission modes: transparent mode (TM); unacknowledged mode (UM); and acknowledged mode (AM). Based on the transmission mode an RLC is operating, the RLC may perform one or more of the noted functions. The RLC configuration may be per logical channel with no dependency on numerologies and / or Transmission Time Interval (TTI) durations. As shown in FIG. 3, the RLCs 213 and 223 may provide RLC channels as a service to PDCPs 214 and 224, respectively.

[0089] The MACs 212 and 222 may perform multiplexing / demultiplexing of logical channels and / or mapping between logical channels and transport channels. The multiplexing / demultiplexing may include multiplexing / demultiplexing of data units, belonging to the one or more logical channels, into / from Transport Blocks (TBs) delivered to / from the PHYs 211 and 221 . The MAC 222 may be configured to perform scheduling, scheduling information reporting, and priority handling between UEs by means of dynamic scheduling. Scheduling may be performed in the gNB 220 (at the MAC 222) for downlink and uplink. The MACs 212 and 222 may be configured to perform error correction through Hybrid Automatic Repeat Request (HARQ) (e.g., one HARQ entity per carrier in case of Carrier Aggregation (CA)), priority handling between logical channels of the UE 210 by means of logical channel prioritization, and / or padding. The MACs 212 and 222 may support one or more numerologies and / or transmission timings. In an example, mapping restrictions in a logical channel prioritization may control which numerology and / or transmission timing a logical channel may use. As shown in FIG. 3, the MACs 212 and 222 may provide logical channels as a service to the RLCs 213 and 223.

[0090] The PHYs 211 and 221 may perform mapping of transport channels to physical channels and digital and analog signal processing functions for sending and receiving information over the air interface. These digital and analog signal processing functions may include, for example, coding / decoding and modulation / demodulation. The PHYs 211 and 221 may perform multi-antenna mapping. As shown in FIG.3, the PHYs 211 and 221 may provide one or more transport channels as a service to the MACs 212 and 222

[0091] FIG. 4A illustrates an example downlink data flow through the NR user plane protocol stack. FIG. 4A illustrates a downlink data flow of three IP packets (n, n+1 , and m) through the NR user plane protocol stack to generate two TBs at the gNB 220. An uplink data flow through the NR user plane protocol stack may be similar to the downlink data flow depicted in FIG. 4A.

[0092] The downlink data flow of FIG. 4A begins when SDAP 225 receives the three IP packets from one or more QoS flows and maps the three packets to radio bearers. In FIG. 4A, the SDAP 225 maps IP packets n and n+1 to a first radio bearer 402 and maps IP packet m to a second radio bearer 404. An SDAP header (labeled with an "H” in FIG. 4A) is added to an IP packet. The data unit from / to a higher protocol layer is referred to as a service data unit (SDU) of the lower protocol layer and the data unit to / from a lower protocol layer is referred to as a protocol data unit (PDU) of the higher protocol layer. As shown inFIG 4A, the data unit from the SDAP 225 is an SDU of lower protocol layer PDCP 224 and is a PDU of the SDAP 225.

[0093] The remaining protocol layers in FIG. 4A may perform their associated functionality (e.g with respect to FIG. 3), add corresponding headers, and forward their respective outputs to the next lower layer. For example, the PDCP 224 may perform IP-header compression and ciphering and forward its output to the RLC 223. The RLC 223 may optionally perform segmentation (e.g., as shown for IP packet m in FIG. 4A) and forward its output to the MAC 222. The MAC 222 may multiplex a number of RLC PDUs and may attach a MAC subheader to an RLC PDU to form a transport block. In NR, the MAC subheaders may be distributed across the MAC PDU, as illustrated in FIG. 4A. In LTE, the MAC subheaders may be entirely located at the beginning of the MAC PDU. The NR MAC PDU structure may reduce processing time and associated latency because the MAC PDU subheaders may be computed before the full MAC PDU is assembled.

[0094] FIG. 4B illustrates an example format of a MAC subheader in a MAC PDU. The MAC subheader includes: an SDU length field for indicating the length (e.g., in bytes) of the MAC SDU to which the MAC subheader corresponds; a logical channel identifier (LCID) field for identifying the logical channel from which the MAC SDU originated to aid in the demultiplexing process; a flag (F) for indicating the size of the SDU length field; and a reserved bit (R) field for future use.

[0095] FIG. 4B further illustrates MAC control elements (CEs) inserted into the MAC PDU by a MAC, such as MAC 212 or MAC 222 For example, FIG. 4B illustrates two MAC CEs inserted into the MAC PDU. MAC CEs may be inserted at the beginning of a MAC PDU for downlink transmissions (as shown in FIG. 4B) and at the end of a MAC PDU for uplink transmissions. MAC CEs may be used for in-band control signaling. Example MAC CEs include: scheduling-related MAC CEs, such as buffer status reports and power headroom reports; activation / deactivation MAC CEs, such as those for activation / deactivation of PDCP duplication detection, channel state information (CSI) reporting, sounding reference signal (SRS) transmission, and prior configured components; discontinuous reception (DRX) related MAC CEs; timing advance MAC CEs; and random access related MAC CEs. A MAC CE may be preceded by a MAC subheader with a similar format as described for MAC SDUs and may be identified with a reserved value in the LCID field that indicates the type of control information included in the MAC CE.

[0096] Before describing the NR control plane protocol stack, logical channels, transport channels, and physical channels are first described as well as a mapping between the channel types. One or more of the channels may be used to carry out functions associated with the NR control plane protocol stack described later below.

[0097] FIG. 5A and FIG. 5B illustrate, for downlink and uplink respectively, a mapping between logical channels, transport channels, and physical channels. Information is passed through channels between theRLC, the MAC, and the PHY of the NR protocol stack. A logical channel may be used between the RLC and the MAC and may be classified as a control channel that carries control and configuration information in the NR control plane or as a traffic channel that carries data in the NR user plane. A logical channel may be classified as a dedicated logical channel that is dedicated to a specific UE or as a common logical channel that may be used by more than one UE. A logical channel may also be defined by the type of information it carries. The set of logical channels defined by NR includes, for example:

[0098] - a paging control channel (PCCH) for carrying paging messages used to page a UE whose location is not known to the network on a cell level;

[0099] - a broadcast control channel (BCCH) for carrying system information messages in the form of a master information block (M I B) and several system information blocks (SIBs), wherein the system information messages may be used by the UEs to obtain information about how a cell is configured and how to operate within the cell;

[0100] - a common control channel (CCCH) for carrying control messages together with random access;

[0101] - a dedicated control channel (DCCH) for carrying control messages to / from a specific the UE to configure the UE; and

[0102] - a dedicated traffic channel (DTCH) for carrying user data to / from a specific the UE.

[0103] Transport channels are used between the MAC and PHY layers and may be defined by how the information they carry is transmitted over the air interface. The set of transport channels defined by NR includes, for example:

[0104] -- a paging channel (PCH) for carrying paging messages that originated from the PCCH;

[0105] -- a broadcast channel (BCH) for carrying the MIB from the BCCH;

[0106] - a downlink shared channel (DL-SCH) for carrying downlink data and signaling messages, including the SIBs from the BCCH;

[0107] - an uplink shared channel (UL-SCH) for carrying uplink data and signaling messages; and

[0108] - a random access channel (RACH) for allowing a UE to contact the network without any prior scheduling.

[0109] The PHY may use physical channels to pass information between processing levels of the PHY. A physical channel may have an associated set of time-frequency resources for carrying the information of one or more transport channels. The PHY may generate control information to support the low-level operation of the PHY and provide the control information to the lower levels of the PHY via physical control channels, known as L1 / L2 control channels. The set of physical channels and physical control channels defined by NR includes, for example:

[0110] - a physical broadcast channel (PBCH) for carrying the MIB from the BCH;

[0111] - a physical downlink shared channel (PDSCH) for carrying downlink data and signaling messages from the DL-SCH, as well as paging messages from the PCH;

[0112] -- a physical downlink control channel (PDCCH) for carrying downlink control information (DCI), which may include downlink scheduling commands, uplink scheduling grants, and uplink power control commands;

[0113] - a physical uplink shared channel (PUSCH) for carrying uplink data and signaling messages from the UL-SCH and in some instances uplink control information (UCI) as described below;

[0114] - a physical uplink control channel (PUCCH) for carrying UCI, which may include HARQ acknowledgments, channel quality indicators (CQI), pre-coding matrix indicators (PM I), rank indicators (Rl), and scheduling requests (SR); and

[0115] - a physical random access channel (PRACH) for random access.

[0116] Similar to the physical control channels, the physical layer generates physical signals to support the low-level operation of the physical layer. As shown in FIG. 5A and FIG. 5B, the physical layer signals defined by NR include: primary synchronization signals (PSS), secondary synchronization signals (SSS), channel state information reference signals (CSI-RS), demodulation reference signals (DMRS), sounding reference signals (SRS), and phase-tracking reference signals (PT-RS). These physical layer signals will be described in greater detail below.

[0117] FIG. 2B illustrates an example NR control plane protocol stack. As shown in FIG. 2B, the NR control plane protocol stack may use the same / similar first four protocol layers as the example NR user plane protocol stack. These four protocol layers include the PHYs 211 and 221 , the MACs 212 and 222, the RLCs 213 and 223, and the PDCPs 214 and 224. Instead of having the SDAPs 215 and 225 at the top of the stack as in the NR user plane protocol stack, the NR control plane stack has radio resource controls (RRCs) 216 and 226 and NAS protocols 217 and 237 at the top of the NR control plane protocol stack.

[0118] The NAS protocols 217 and 237 may provide control plane functionality between the UE 210 and the AMF 230 (e.g., the AMF 158A) or, more generally, between the UE 210 and the CN. The NAS protocols 217 and 237 may provide control plane functionality between the UE 210 and the AMF 230 via signaling messages, referred to as NAS messages. There is no direct path between the UE 210 and the AMF 230 through which the NAS messages can be transported. The NAS messages may be transported using the AS of the Uu and NG interfaces. NAS protocols 217 and 237 may provide control plane functionality such as authentication, security, connection setup, mobility management, and session management.

[0119] The RRCs 216 and 226 may provide control plane functionality between the UE 210 and the gNB 220 or, more generally, between the UE 210 and the RAN. The RRCs 216 and 226 may provide control plane functionality between the UE 210 and the gNB 220 via signaling messages, referred to as RRC messages. RRC messages may be transmitted between the UE 210 and the RAN using signaling radiobearers and the same / similar PDCP, RLC, MAC, and PHY protocol layers. The MAC may multiplex controlplane and user-plane data into the same transport block (TB). The RRCs 216 and 226 may provide control plane functionality such as: broadcast of system information related to AS and NAS; paging initiated by the CN or the RAN; establishment, maintenance and release of an RRC connection between the UE 210 and the RAN; security functions including key management; establishment, configuration, maintenance and release of signaling radio bearers and data radio bearers; mobility functions; QoS management functions; the UE measurement reporting and control of the reporting; detection of and recovery from radio link failure (RLF); and / or NAS message transfer. As part of establishing an RRC connection, RRCs 216 and 226 may establish an RRC context, which may involve configuring parameters for communication between the UE 210 and the RAN.

[0120] FIG. 6 is an example diagram showing RRC state transitions of a UE. The UE may be the same or similar to the wireless device 106 depicted in FIG. 1A, the UE 210 depicted in FIG. 2A and FIG. 2B, or any other wireless device described in the present disclosure. As illustrated in FIG. 6, a UE may be in at least one of three RRC states: RRC connected 602 (e.g ., RRC_CONNECTED), RRC idle 604 (e.g., RRC_I OLE), and RRC inactive 606 (e.g., RRCJNACTIVE).

[0121] In RRC connected 602, the UE has an established RRC context and may have at least one RRC connection with a base station. The base station may be similar to one of the one or more base stations included in the RAN 104 depicted in FIG. 1A, one of the gNBs 160 or ng-eNBs 162 depicted in FIG. 1 B, the gNB 220 depicted in FIG. 2A and FIG. 2B, or any other base station described in the present disclosure. The base station with which the UE is connected may have the RRC context for the UE. The RRC context, referred to as the UE context, may comprise parameters for communication between the UE and the base station. These parameters may include, for example: one or more AS contexts; one or more radio link configuration parameters; bearer configuration information (e.g., relating to a data radio bearer, signaling radio bearer, logical channel, QoS flow, and / or PDU session); security information; and / or PHY, MAC, RLC, PDCP, and / or SDAP layer configuration information. While in RRC connected 602, mobility of the UE may be managed by the RAN (e.g., the RAN 104 or the NG-RAN 154). The UE may measure the signal levels (e.g., reference signal levels) from a serving cell and neighboring cells and report these measurements to the base station currently serving the UE. The UE's serving base station may request a handover to a cell of one of the neighboring base stations based on the reported measurements. The RRC state may transition from RRC connected 602 to RRC idle 604 through a connection release procedure 608 or to RRC inactive 606 through a connection inactivation procedure 610.

[0122] In RRC idle 604, an RRC context may not be established for the UE. In RRC idle 604, the UE may not have an RRC connection with the base station. While in RRC idle 604, the UE may be in a sleep state for the majority of the time (e.g., to conserve battery power). The UE may wake up periodically (e.g., oncein every discontinuous reception cycle) to monitor for paging messages from the RAN. Mobility of the UE may be managed by the UE through a procedure known as cell reselection. The RRC state may transition from RRC idle 604 to RRC connected 602 through a connection establishment procedure 612, which may involve a random access procedure as discussed in greater detail below.

[0123] In RRC inactive 606, the RRC context previously established is maintained in the UE and the base station. This allows for a fast transition to RRC connected 602 with reduced signaling overhead as compared to the transition from RRC idle 604 to RRC connected 602. While in RRC inactive 606, the UE may be in a sleep state and mobility of the UE may be managed by the UE through cell reselection. The RRC state may transition from RRC inactive 606 to RRC connected 602 through a connection resume procedure 614 or to RRC idle 604 though a connection release procedure 616 that may be the same as or similar to connection release procedure 608.

[0124] An RRC state may be associated with a mobility management mechanism. In RRC idle 604 and RRC inactive 606, mobility is managed by the UE through cell reselection. The purpose of mobility management in RRC idle 604 and RRC inactive 606 is to allow the network to be able to notify the UE of an event via a paging message without having to broadcast the paging message over the entire mobile communications network. The mobility management mechanism used in RRC idle 604 and RRC inactive 606 may allow the network to track the UE on a cell-group level so that the paging message may be broadcast over the cells of the cell group that the UE currently resides within instead of the entire mobile communication network. The mobility management mechanisms for RRC idle 604 and RRC inactive 606 track the UE on a cell-group level. They may do so using different granularities of grouping. For example, there may be three levels of cell-grouping granularity: individual cells; cells within a RAN area identified by a RAN area identifier (RAI); and cells within a group of RAN areas, referred to as a tracking area and identified by a tracking area identifier (TAI).

[0125] Tracking areas may be used to track the UE at the CN level. The CN (e.g., the CN 102 or the 5G-CN 152) may provide the UE with a list of TAIs associated with a UE registration area. If the UE moves, through cell reselection, to a cell associated with a TAI not included in the list of TAIs associated with the UE registration area, the UE may perform a registration update with the CN to allow the CN to update the UE’s location and provide the UE with a new the UE registration area.

[0126] RAN areas may be used to track the UE at the RAN level. For a UE in RRC inactive 606 state, the UE may be assigned a RAN notification area. A RAN notification area may comprise one or more cell identities, a list of RAIs, or a list of TAIs. In an example, a base station may belong to one or more RAN notification areas. In an example, a cell may belong to one or more RAN notification areas. If the UE moves, through cell reselection, to a cell not included in the RAN notification area assigned to the UE, the UE may perform a notification area update with the RAN to update the UE's RAN notification area.

[0127] A base station storing an RRC context for a UE or a last serving base station of the UE may be referred to as an anchor base station. An anchor base station may maintain an RRC context for the UE at least during a period of time that the UE stays in a RAN notification area of the anchor base station and / or during a period of time that the UE stays in RRC inactive 606.

[0128] A g N B, such as gNBs 160 in FIG. 1 B, may be split into two parts: a central unit (gNB-CU), and one or more distributed units (gNB-DU). A gNB-CU may be coupled to one or more gNB-DUs using an F1 interface. The gNB-CU may comprise the RRC, the PDCP, and the SDAP. A gNB-DU may comprise the RLC, the MAC, and the PHY.

[0129] In NR, the physical signals and physical channels (discussed with respect to FIG. 5A and FIG. 5B) may be mapped onto orthogonal frequency divisional multiplexing (OFDM) symbols. OFDM is a multicarrier communication scheme that transmits data over F orthogonal subcarriers (or tones). Before transmission, the data may be mapped to a series of complex symbols (e.g., M-quadrature amplitude modulation (M- QAM) or M-phase shift keying (M-PSK) symbols), referred to as source symbols, and divided into F parallel symbol streams. The F parallel symbol streams may be treated as though they are in the frequency domain and used as inputs to an Inverse Fast Fourier Transform (IFFT) block that transforms them into the time domain. The IFFT block may take in F source symbols at a time, one from each of the F parallel symbol streams, and use each source symbol to modulate the amplitude and phase of one of F sinusoidal basis functions that correspond to the F orthogonal subcarriers. The output of the IFFT block may be F timedomain samples that represent the summation of the F orthogonal subcarriers. The F time-domain samples may form a single OFDM symbol. After some processing (e.g., addition of a cyclic prefix) and up- conversion, an OFDM symbol provided by the IFFT block may be transmitted over the air interface on a carrier frequency. The F parallel symbol streams may be mixed using an FFT block before being processed by the IFFT block. This operation produces Discrete Fourier Transform (DFT)-precoded OFDM symbols and may be used by UEs in the uplink to reduce the peak to average power ratio (PAPR). Inverse processing may be performed on the OFDM symbol at a receiver using an FFT block to recover the data mapped to the source symbols.

[0130] FIG. 7 illustrates an example configuration of an NR frame into which OFDM symbols are grouped. An NR frame may be identified by a system frame number (SFN). The SFN may repeat with a period of 1024 frames. As illustrated, one NR frame may be 10 milliseconds (ms) in duration and may include 10 subframes that are 1 ms in duration. A subframe may be divided into slots that include, for example, 14 OFDM symbols per slot.

[0131] The duration of a slot may depend on the numerology used for the OFDM symbols of the slot. In NR, a flexible numerology is supported to accommodate different cell deployments (e g., cells with carrier frequencies below 1 GHz up to cells with carrier frequencies in the mm-wave range). A numerology may bedefined in terms of subcarrier spacing and cyclic prefix duration. For a numerology in NR, subcarrier spacings may be scaled up by powers of two from a baseline subcarrier spacing of 15 kHz, and cyclic prefix durations may be scaled down by powers of two from a baseline cyclic prefix duration of 4.7 ps. For example, NR defines numerologies with the following subcarrier spacing / cyclic prefix duration combinations: 15 kHz / 4.7 ps; 30 kHz / 2.3 ps; 60 kHz / 1.2 ps; 120 kHz / 0.59 ps; and 240 kHz / 0.29 ps.

[0132] A slot may have a fixed number of OFDM symbols (e.g., 14 OFDM symbols). A numerology with a higher subcarrier spacing has a shorter slot duration and, correspondingly, more slots per subframe. FIG. 7 illustrates this numerology-dependent slot duration and slots-per-subframe transmission structure (the numerology with a subcarrier spacing of 240 kHz is not shown in FIG. 7 for ease of illustration). A subframe in NR may be used as a numerology-independent time reference, while a slot may be used as the unit upon which uplink and downlink transmissions are scheduled. To support low latency, scheduling in NR may be decoupled from the slot duration and start at any OFDM symbol and last for as many symbols as needed for a transmission. These partial slot transmissions may be referred to as mini-slot or subslot transmissions.

[0133] FIG. 8 illustrates an example configuration of a slot in the time and frequency domain for an NR carrier. The slot includes resource elements (REs) and resource blocks (RBs). An RE is the smallest physical resource in NR. An RE spans one OFDM symbol in the time domain by one subcarrier in the frequency domain as shown in FIG. 8. An RB spans twelve consecutive REs in the frequency domain as shown in FIG. 8. An NR carrier may be limited to a width of 275 RBs or 275x12 = 3300 subcarriers. Such a limitation, if used, may limit the NR carrier to 50, 100, 200, and 400 MHz for subcarrier spacings of 15, 30, 60, and 120 kHz, respectively, where the 400 MHz bandwidth may be set based on a 400 MHz per carrier bandwidth limit.

[0134] FIG. 8 illustrates a single numerology being used across the entire bandwidth of the NR carrier. In other example configurations, multiple numerologies may be supported on the same carrier.

[0135] NR may support wide carrier bandwidths (e.g., up to 400 MHz for a subcarrier spacing of 120 kHz). Not all UEs may be able to receive the full carrier bandwidth (e.g., due to hardware limitations). Also, receiving the full carrier bandwidth may be prohibitive in terms of UE power consumption. In an example, to reduce power consumption and / or for other purposes, a UE may adapt the size of the UE's receive bandwidth based on the amount of traffic the UE is scheduled to receive. This is referred to as bandwidth adaptation.

[0136] NR defines bandwidth parts (BWPs) to support UEs not capable of receiving the full carrier bandwidth and to support bandwidth adaptation. In an example, a BWP may be defined by a subset of contiguous RBs on a carrier. A UE may be configured (e.g., via RRC layer) with one or more downlink BWPs and one or more uplink BWPs per serving cell (e.g., up to four downlink BWPs and up to four uplinkBWPs per serving cell). At a given time, one or more of the configured BWPs for a serving cell may be active. These one or more BWPs may be referred to as active BWPs of the serving cell. When a serving cell is configured with a secondary uplink carrier, the serving cell may have one or more first active BWPs in the uplink carrier and one or more second active BWPs in the secondary uplink carrier.

[0137] For unpaired spectra, a downlink BWP from a set of configured downlink BWPs may be linked with an uplink BWP from a set of configured uplink BWPs if a downlink BWP index of the downlink BWP and an uplink BWP index of the uplink BWP are the same. For unpaired spectra, a UE may expect that a center frequency for a downlink BWP is the same as a center frequency for an uplink BWP.

[0138] For a downlink BWP in a set of configured downlink BWPs on a primary cell (PCell) , a base station may configure a UE with one or more control resource sets (CORESETs) for at least one search space. A search space is a set of locations in the time and frequency domains where the UE may find control information. The search space may be a UE-specific search space or a common search space (potentially usable by a plurality of UEs). For example, a base station may configure a UE with a common search space, on a PCell or on a primary secondary cell (PSCell), in an active downlink BWP.

[0139] For an uplink BWP in a set of configured uplink BWPs, a BS may configure a UE with one or more resource sets for one or more PUCCH transmissions. A UE may receive downlink receptions (e.g., PDCCH or PDSCH) in a downlink BWP according to a configured numerology (e.g., subcarrier spacing and cyclic prefix duration) for the downlink BWP. The UE may transmit uplink transmissions (e.g., PUCCH or PUSCH) in an uplink BWP according to a configured numerology (e.g., subcarrier spacing and cyclic prefix length for the uplink BWP).

[0140] One or more BWP indicator fields may be provided in Downlink Control Information (DCI). A value of a BWP indicator field may indicate which BWP in a set of configured BWPs is an active downlink BWP for one or more downlink receptions. The value of the one or more BWP indicator fields may indicate an active uplink BWP for one or more uplink transmissions.

[0141] A base station may semi-statically configure a UE with a default downlink BWP within a set of configured downlink BWPs associated with a PCell. If the base station does not provide the default downlink BWP to the UE, the default downlink BWP may be an initial active downlink BWP. The UE may determine which BWP is the initial active downlink BWP based on a CORESET configuration obtained using the PBCH.

[0142] A base station may configure a UE with a BWP inactivity timer value for a PCell. The UE may start or restart a BWP inactivity timer at any appropriate time. For example, the UE may start or restart the BWP inactivity timer (a) when the UE detects a DCI indicating an active downlink BWP other than a default downlink BWP for a paired spectra operation; or (b) when a UE detects a DCI indicating an active downlink BWP or active uplink BWP other than a default downlink BWP or uplink BWP for an unpaired spectraoperation. If the UE does not detect DCI during an interval of time (e.g., 1 ms or 0.5 ms), the UE may run the BWP inactivity timer toward expiration (for example, increment from zero to the BWP inactivity timer value, or decrement from the BWP inactivity timer value to zero). When the BWP inactivity timer expires, the UE may switch from the active downlink BWP to the default downlink BWP.

[0143] In an example, a base station may semi-statically configure a UE with one or more BWPs. A UE may switch an active BWP from a first BWP to a second BWP in response to receiving a DCI indicating the second BWP as an active BWP and / or in response to an expiry of the BWP inactivity timer (e.g., if the second BWP is the default BWP).

[0144] Downlink and uplink BWP switching (where BWP switching refers to switching from a currently active BWP to a not currently active BWP) may be performed independently in paired spectra. In unpaired spectra, downlink and uplink BWP switching may be performed simultaneously. Switching between configured BWPs may occur based on RRC signaling, DCI, expiration of a BWP inactivity timer, and / or an initiation of random access.

[0145] FIG. 9 illustrates an example of bandwidth adaptation using three configured BWPs for an NR carrier. A UE configured with the three BWPs may switch from one BWP to another BWP at a switching point. In the example illustrated in FIG. 9, the BWPs include: a BWP 902 with a bandwidth of 40 MHz and a subcarrier spacing of 15 kHz; a BWP 904 with a bandwidth of 10 MHz and a subcarrier spacing of 15 kHz; and a BWP 906 with a bandwidth of 20 MHz and a subcarrier spacing of 60 kHz. The BWP 902 may be an initial active BWP, and the BWP 904 may be a default BWP. The UE may switch between BWPs at switching points. In the example of FIG. 9, the UE may switch from the BWP 902 to the BWP 904 at a switching point 908. The switching at the switching point 908 may occur for any suitable reason, for example, in response to an expiry of a BWP inactivity timer (indicating switching to the default BWP) and / or in response to receiving a DCI indicating BWP 904 as the active BWP. The UE may switch at a switching point 910 from active BWP 904 to BWP 906 in response to receiving a DCI indicating BWP 906 as the active BWP. The UE may switch at a switching point 912 from active BWP 906 to BWP 904 in response to an expiry of a BWP inactivity timer and / or in response to receiving a DCI indicating BWP 904 as the active BWP. The UE may switch at a switching point 914 from active BWP 904 to BWP 902 in response to receiving a DCI indicating BWP 902 as the active BWP.

[0146] If a UE is configured for a secondary cell with a default downlink BWP in a set of configured downlink BWPs and a timer value, UE procedures for switching BWPs on a secondary cell may be the same / similar as those on a primary cell. For example, the UE may use the timer value and the default downlink BWP for the secondary cell in the same / similar manner as the UE would use these values for a primary cell.

[0147] To provide for greater data rates, two or more carriers can be aggregated and simultaneously transmitted to / from the same UE using carrier aggregation (CA). The aggregated carriers in CA may be referred to as component carriers (CCs). When CA is used, there are a number of serving cells for the UE, one for a CC. The CCs may have three configurations in the frequency domain.

[0148] FIG. 10A illustrates the three CA configurations with two CCs. In the intraband, contiguous configuration 1002, the two CCs are aggregated in the same frequency band (frequency band A) and are located directly adjacent to each other within the frequency band. In the intraband, non-contiguous configuration 1004, the two CCs are aggregated in the same frequency band (frequency band A) and are separated in the frequency band by a gap. In the interband configuration 1006, the two CCs are located in frequency bands (frequency band A and frequency band B).

[0149] In an example, up to 32 CCs may be aggregated. The aggregated CCs may have the same or different bandwidths, subcarrier spacing, and / or duplexing schemes (TDD or FDD). A serving cell for a UE using CA may have a downlink CC. For FDD, one or more uplink CCs may be optionally configured for a serving cell. The ability to aggregate more downlink carriers than uplink carriers may be useful, for example, when the UE has more data traffic in the downlink than in the uplink.

[0150] When CA is used, one of the aggregated cells for a UE may be referred to as a primary cell (PCell). The PCell may be the serving cell that the UE initially connects to at RRC connection establishment, reestablishment, and / or handover. The PCell may provide the UE with NAS mobility information and the security input. UEs may have different PCells. In the downlink, the carrier corresponding to the PCell may be referred to as the downlink primary CC (DL PCC). In the uplink, the carrier corresponding to the PCell may be referred to as the uplink primary CC (UL PCC). The other aggregated cells for the UE may be referred to as secondary cells (SCells). In an example, the SCells may be configured after the PCell is configured for the UE. For example, an SCell may be configured through an RRC Connection Reconfiguration procedure. In the downlink, the carrier corresponding to an SCell may be referred to as a downlink secondary CC (DL SCC). In the uplink, the carrier corresponding to the SCell may be referred to as the uplink secondary CC (UL SCC).

[0151] Configured SCells for a UE may be activated and deactivated based on, for example, traffic and channel conditions Deactivation of an SCell may mean that PDCCH and PDSCH reception on the SCell is stopped and PUSCH, SRS, and CQI transmissions on the SCell are stopped. Configured SCells may be activated and deactivated using a MAC CE with respect to FIG. 4B. For example, a MAC CE may use a bitmap (e.g., one bit per SCell) to indicate which SCells (e.g., in a subset of configured SCells) for the UE are activated or deactivated. Configured SCells may be deactivated in response to an expiration of an SCell deactivation timer (e.g., one SCell deactivation timer per SCell).

[0152] Downlink control information, such as scheduling assignments and scheduling grants, for a cell may be transmitted on the cell corresponding to the assignments and grants, which is known as selfscheduling. The DCI for the cell may be transmitted on another cell, which is known as cross-carrier scheduling. Uplink control information (e.g., HARQ acknowledgments and channel state feedback, such as CQI, PMI, and / or Rl) for aggregated cells may be transmitted on the PUCCH of the PCell. For a larger number of aggregated downlink CCs, the PUCCH of the PCell may become overloaded. Cells may be divided into multiple PUCCH groups.

[0153] FIG. 10B illustrates an example of how aggregated cells may be configured into one or more PUCCH groups. A PUCCH group 1010 and a PUCCH group 1050 may include one or more downlink CCs, respectively. In the example of FIG. 10B, the PUCCH group 1010 includes three downlink CCs: a PCell 1011 , an SCell 1012, and an SCell 1013. The PUCCH group 1050 includes three downlink CCs in the present example: a PCell 1051 , an SCell 1052, and an SCell 1053. One or more uplink CCs may be configured as a PCell 1021 , an SCell 1022, and an SCell 1023. One or more other uplink CCs may be configured as a primary SCell (PSCell) 1061 , an SCell 1062, and an SCell 1063. Uplink control information (UCI) related to the downlink CCs of the PUCCH group 1010, shown as UC1 1031 , UC1 1032, and UCI 1033, may be transmitted in the uplink of the PCell 1021 . Uplink control information (UCI) related to the downlink CCs of the PUCCH group 1050, shown as UCI 1071 , UC1 1072, and UCI 1073, may be transmitted in the uplink of the PSCell 1061. In an example, if the aggregated cells depicted in FIG. 10B were not divided into the PUCCH group 1010 and the PUCCH group 1050, a single uplink PCell to transmit UCI relating to the downlink CCs, and the PCell may become overloaded. By dividing transmissions of UCI between the PCell 1021 and the PSCell 1061 , overloading may be prevented.

[0154] A cell, comprising a downlink carrier and optionally an uplink carrier, may be assigned with a physical cell ID and a cell index. The physical cell ID or the cell index may identify a downlink carrier and / or an uplink carrier of the cell, for example, depending on the context in which the physical cell ID is used A physical cell ID may be determined using a synchronization signal transmitted on a downlink component carrier. A cell index may be determined using RRC messages. In the disclosure, a physical cell ID may be referred to as a carrier ID, and a cell index may be referred to as a carrier index. For example, when the disclosure refers to a first physical cell ID for a first downlink carrier, the disclosure may mean the first physical cell ID is for a cell comprising the first downlink carrier. The same / similar concept may apply to, for example, a carrier activation. When the disclosure indicates that a first carrier is activated, the specification may mean that a cell comprising the first carrier is activated.

[0155] In CA, a multi-carrier nature of a PHY may be exposed to a MAC. In an example, a HARQ entity may operate on a serving cell A transport block may be generated per assignment / grant per serving cell Atransport block and potential HARQ retransmissions of the transport block may be mapped to a serving cell.

[0156] In the downlink, a base station may transmit (e.g., unicast, multicast, and / or broadcast) one or more Reference Signals (RSs) to a UE (e.g., PSS, SSS, CSI-RS, DMRS, and / or PT-RS, as shown in FIG. 5A). In the uplink, the UE may transmit one or more RSs to the base station (e.g., DMRS, PT-RS, and / or SRS, as shown in FIG. 5B). The PSS and the SSS may be transmitted by the base station and used by the UE to synchronize the UE to the base station. The PSS and the SSS may be provided in a synchronization signal (SS) / physical broadcast channel (PBCH) block that includes the PSS, the SSS, and the PBCH. The base station may periodically transmit a burst of SS / PBCH blocks.

[0157] FIG. 11A illustrates an example of an SS / PBCH block's structure and location. A burst of SS / PBCH blocks may include one or more SS / PBCH blocks (e.g., 4 SS / PBCH blocks, as shown in FIG. 11A). Bursts may be transmitted periodically (e.g., every 2 frames or 20 ms). A burst may be restricted to a half-frame (e.g., a first half-frame having a duration of 5 ms). It will be understood that FIG. 11A is an example, and that these parameters (number of SS / PBCH blocks per burst, periodicity of bursts, position of burst within the frame) may be configured based on, for example: a carrier frequency of a cell in which the SS / PBCH block is transmitted; a numerology or subcarrier spacing of the cell; a configuration by the network (e.g., using RRC signaling); or any other suitable factor. In an example, the UE may assume a subcarrier spacing for the SS / PBCH block based on the carrier frequency being monitored, unless the radio network configured the UE to assume a different subcarrier spacing.

[0158] The SS / PBCH block may span one or more OFDM symbols in the time domain (e.g., 4 OFDM symbols, as shown in the example of FIG. 11 A) and may span one or more subcarriers in the frequency domain (e.g., 240 contiguous subcarriers). The PSS, the SSS, and the PBCH may have a common center frequency. The PSS may be transmitted first and may span, for example, 1 OFDM symbol and 127 subcarriers. The SSS may be transmitted after the PSS (e.g., two symbols later) and may span 1 OFDM symbol and 127 subcarriers. The PBCH may be transmitted after the PSS (e.g., across the next 3 OFDM symbols) and may span 240 subcarriers.

[0159] The location of the SS / PBCH block in the time and frequency domains may not be known to the UE (e.g., if the UE is searching for the cell). To find and select the cell, the UE may monitor a carrier for the PSS. For example, the UE may monitor a frequency location within the carrier. If the PSS is not found after a certain duration (e.g., 20 ms), the UE may search for the PSS at a different frequency location within the carrier, as indicated by a synchronization raster. If the PSS is found at a location in the time and frequency domains, the UE may determine, based on a known structure of the SS / PBCH block, the locations of the SSS and the PBCH, respectively. The SS / PBCH block may be a cell-defining SS block (CD-SSB). In an example, a primary cell may be associated with a CD-SSB. The CD-SSB may be located on asynchronization raster. In an example, a cell selection / search and / or reselection may be based on the CD- SSB.

[0160] The SS / PBCH block may be used by the UE to determine one or more parameters of the cell. For example, the UE may determine a physical cell identifier (PCI) of the cell based on the sequences of the PSS and the SSS, respectively. The UE may determine a location of a frame boundary of the cell based on the location of the SS / PBCH block. For example, the SS / PBCH block may indicate that it has been transmitted in accordance with a transmission pattern, wherein a SS / PBCH block in the transmission pattern is a known distance from the frame boundary.

[0161] The PBCH may use a QPSK modulation and may use forward error correction (FEC). The FEC may use polar coding. One or more symbols spanned by the PBCH may carry one or more DMRSs for demodulation of the PBCH. The PBCH may include an indication of a current system frame number (SFN) of the cell and / or a SS / PBCH block timing index. These parameters may facilitate time synchronization of the UE to the base station. The PBCH may include a master information block (MIB) used to provide the UE with one or more parameters. The MIB may be used by the UE to locate remaining minimum system information (RMSI) associated with the cell. The RMSI may include a System Information Block Type 1 (SIB1 ). The SIB1 may contain information needed by the UE to access the cell. The UE may use one or more parameters of the MIB to monitor PDCCH, which may be used to schedule PDSCH. The PDSCH may include the SIB1 . The SIB1 may be decoded using parameters provided in the MIB. The PBCH may indicate an absence of SIB1 . Based on the PBCH indicating the absence of SIB1 , the UE may be pointed to a frequency. The UE may search for an SS / PBCH block at the frequency to which the UE is pointed.

[0162] The UE may assume that one or more SS / PBCH blocks transmitted with a same SS / PBCH block index are quasi co-located (QCLed) (e.g. , having the same / similar Doppler spread, Doppler shift, average gain, average delay, and / or spatial Rx parameters). The UE may not assume QCL for SS / PBCH block transmissions having different SS / PBCH block indices.

[0163] SS / PBCH blocks (e.g., those within a half-frame) may be transmitted in spatial directions (e.g., using different beams that span a coverage area of the cell). In an example, a first SS / PBCH block may be transmitted in a first spatial direction using a first beam, and a second SS / PBCH block may be transmitted in a second spatial direction using a second beam.

[0164] In an example, within a frequency span of a carrier, a base station may transmit a plurality of SS / PBCH blocks. In an example, a first PCI of a first SS / PBCH block of the plurality of SS / PBCH blocks may be different from a second PCI of a second SS / PBCH block of the plurality of SS / PBCH blocks. The PCIs of SS / PBCH blocks transmitted in different frequency locations may be different or the same.

[0165] The CSI-RS may be transmitted by the base station and used by the UE to acquire channel state information (CSI). The base station may configure the UE with one or more CSI-RSs for channel estimationor any other suitable purpose. The base station may configure a UE with one or more of the same / similar CSI-RSs. The UE may measure the one or more CSI-RSs. The UE may estimate a downlink channel state and / or generate a CSI report based on the measuring of the one or more downlink CSI-RSs. The UE may provide the CSI report to the base station. The base station may use feedback provided by the UE (e.g., the estimated downlink channel state) to perform link adaptation.

[0166] The base station may semi-statically configure the UE with one or more CSI-RS resource sets. A CSI-RS resource may be associated with a location in the time and frequency domains and a periodicity. The base station may selectively activate and / or deactivate a CSI-RS resource. The base station may indicate to the UE that a CSI-RS resource in the CSI-RS resource set is activated and / or deactivated.

[0167] The base station may configure the UE to report CSI measurements. The base station may configure the UE to provide CSI reports periodically, aperiodically, or semi-persistently. For periodic CSI reporting, the UE may be configured with a timing and / or periodicity of a plurality of CSI reports. For aperiodic CSI reporting, the base station may request a CSI report. For example, the base station may command the UE to measure a configured CSI-RS resource and provide a CSI report relating to the measurements. For semi-persistent CSI reporting, the base station may configure the UE to transmit periodically, and selectively activate or deactivate the periodic reporting. The base station may configure the UE with a CSI-RS resource set and CSI reports using RRC signaling.

[0168] The CSI-RS configuration may comprise one or more parameters indicating, for example, up to 32 antenna ports. The UE may be configured to employ the same OFDM symbols for a downlink CSI-RS and a control resource set (CORESET) when the downlink CSI-RS and CORESET are spatially QCLed and resource elements associated with the downlink CSI-RS are outside of the physical resource blocks (PRBs) configured for the CORESET. The UE may be configured to employ the same OFDM symbols for downlink CSI-RS and SS / PBCH blocks when the downlink CSI-RS and SS / PBCH blocks are spatially QCLed and resource elements associated with the downlink CSI-RS are outside of PRBs configured for the SS / PBCH blocks.

[0169] Downlink DMRSs may be transmitted by a base station and used by a UE for channel estimation. For example, the downlink DMRS may be used for coherent demodulation of one or more downlink physical channels (e.g., PDSCH). An NR network may support one or more variable and / or configurable DMRS patterns for data demodulation. At least one downlink DMRS configuration may support a front- loaded DMRS pattern. A front-loaded DMRS may be mapped over one or more OFDM symbols (e.g., one or two adjacent OFDM symbols). A base station may semi-statically configure the UE with a number (e.g., a maximum number) of front-loaded DMRS symbols for PDSCH. A DMRS configuration may support one or more DMRS ports. For example, for single user-MIMO, a DMRS configuration may support up to eight orthogonal downlink DMRS ports per UE. For multiuser-MIMO, a DMRS configuration may support up to 4orthogonal downlink DMRS ports per UE. A radio network may support (e.g., at least for CP-OFDM) a common DMRS structure for downlink and uplink, wherein a DMRS location, a DMRS pattern, and / or a scrambling sequence may be the same or different. The base station may transmit a downlink DMRS and a corresponding PDSCH using the same precoding matrix. The UE may use the one or more downlink DMRSs for coherent demodulation / channel estimation of the PDSCH.

[0170] In an example, a transmitter (e.g., a base station) may use a precoder matrices for a part of a transmission bandwidth. For example, the transmitter may use a first precoder matrix for a first bandwidth and a second precoder matrix for a second bandwidth. The first precoder matrix and the second precoder matrix may be different based on the first bandwidth being different from the second bandwidth. The UE may assume that a same precoding matrix is used across a set of PRBs. The set of PRBs may be denoted as a precoding resource block group (PRG).

[0171] A PDSCH may comprise one or more layers. The UE may assume that at least one symbol with DMRS is present on a layer of the one or more layers of the PDSCH. A higher layer may configure up to 3 DMRSs for the PDSCH.

[0172] Downlink PT-RS may be transmitted by a base station and used by a UE for phase-noise compensation. Whether a downlink PT-RS is present or not may depend on an RRC configuration. The presence and / or pattern of the downlink PT-RS may be configured on a UE-specific basis using a combination of RRC signaling and / or an association with one or more parameters employed for other purposes (e.g., modulation and coding scheme (MCS)), which may be indicated by DCI When configured, a dynamic presence of a downlink PT-RS may be associated with one or more DCI parameters comprising at least MCS. An NR network may support a plurality of PT-RS densities defined in the time and / or frequency domains. When present, a frequency domain density may be associated with at least one configuration of a scheduled bandwidth. The UE may assume a same precoding for a DMRS port and a PT-RS port. A number of PT-RS ports may be fewer than a number of DMRS ports in a scheduled resource. Downlink PT-RS may be confined in the scheduled time / frequency duration for the UE. Downlink PT-RS may be transmitted on symbols to facilitate phase tracking at the receiver.

[0173] The UE may transmit an uplink DMRS to a base station for channel estimation. For example, the base station may use the uplink DMRS for coherent demodulation of one or more uplink physical channels. For example, the UE may transmit an uplink DMRS with a PUSCH and / or a PUCCH. The uplink DM-RS may span a range of frequencies that is similar to a range of frequencies associated with the corresponding physical channel. The base station may configure the UE with one or more uplink DMRS configurations. At least one DMRS configuration may support a front-loaded DMRS pattern. The front-loaded DMRS may be mapped over one or more OFDM symbols (e.g., one or two adjacent OFDM symbols). One or more uplink DMRSs may be configured to transmit at one or more symbols of a PUSCH and / or a PUCCH. The basestation may semi-statically configure the UE with a number (e.g., maximum number) of front-loaded DMRS symbols for the PUSCH and / or the PUCCH, which the UE may use to schedule a single-symbol DMRS and / or a double-symbol DMRS. An NR network may support (e.g., for cyclic prefix orthogonal frequency division multiplexing (CP-OFDM)) a common DMRS structure for downlink and uplink, wherein a DMRS location, a DMRS pattern, and / or a scrambling sequence for the DMRS may be the same or different.

[0174] A PUSCH may comprise one or more layers, and the UE may transmit at least one symbol with DMRS present on a layer of the one or more layers of the PUSCH. In an example, a higher layer may configure up to three DMRSs for the PUSCH.

[0175] Uplink PT-RS (which may be used by a base station for phase tracking and / or phase-noise compensation) may or may not be present depending on an RRC configuration of the UE. The presence and / or pattern of uplink PT-RS may be configured on a UE-specific basis by a combination of RRC signaling and / or one or more parameters employed for other purposes (e.g., Modulation and Coding Scheme (MCS), which may be indicated by DCI. When configured, a dynamic presence of uplink PT-RS may be associated with one or more DCI parameters comprising at least MCS. A radio network may support a plurality of uplink PT-RS densities defined in time / frequency domain. When present, a frequency domain density may be associated with at least one configuration of a scheduled bandwidth. The UE may assume a same precoding for a DMRS port and a PT-RS port. A number of PT-RS ports may be fewer than a number of DMRS ports in a scheduled resource. For example, uplink PT-RS may be confined in the scheduled time / frequency duration for the UE.

[0176] SRS may be transmitted by a UE to a base station for channel state estimation to support uplink channel dependent scheduling and / or link adaptation. SRS transmitted by the UE may allow a base station to estimate an uplink channel state at one or more frequencies. A scheduler at the base station may employ the estimated uplink channel state to assign one or more resource blocks for an uplink PUSCH transmission from the UE. The base station may semi-statically configure the UE with one or more SRS resource sets. For an SRS resource set, the base station may configure the UE with one or more SRS resources. An SRS resource set applicability may be configured by a higher layer (e.g., RRC) parameter. For example, when a higher layer parameter indicates beam management, an SRS resource in an SRS resource set of the one or more SRS resource sets (e.g., with the same / similar time domain behavior, periodic, aperiodic, and / or the like) may be transmitted at a time instant (e.g., simultaneously). The UE may transmit one or more SRS resources in SRS resource sets. An NR network may support aperiodic, periodic and / or semi-persistent SRS transmissions. The UE may transmit SRS resources based on one or more trigger types, wherein the one or more trigger types may comprise higher layer signaling (e.g., RRC) and / or one or more DCI formats. In an example, at least one DCI format may be employed for the UE to select at least one of one or more configured SRS resource sets. An SRS trigger type 0 may refer to an SRStriggered based on a higher layer signaling. An SRS trigger type 1 may refer to an SRS triggered based on one or more DCI formats. In an example, when RUSCH and SRS are transmitted in a same slot, the UE may be configured to transmit SRS after a transmission of a RUSCH and a corresponding uplink DMRS.

[0177] The base station may semi-statically configure the UE with one or more SRS configuration parameters indicating at least one of following: a SRS resource configuration identifier; a number of SRS ports; time domain behavior of an SRS resource configuration (e.g., an indication of periodic, semi- persistent, or aperiodic SRS); slot, mini-slot, and / or subframe level periodicity; offset for a periodic and / or an aperiodic SRS resource; a number of OEDM symbols in an SRS resource; a starting OEDM symbol of an SRS resource; an SRS bandwidth; a frequency hopping bandwidth; a cyclic shift; and / or an SRS sequence ID.

[0178] An antenna port is defined such that the channel over which a symbol on the antenna port is conveyed can be inferred from the channel over which another symbol on the same antenna port is conveyed. If a first symbol and a second symbol are transmitted on the same antenna port, the receiver may infer the channel (e.g., fading gain, multipath delay, and / or the like) for conveying the second symbol on the antenna port, from the channel for conveying the first symbol on the antenna port. A first antenna port and a second antenna port may be referred to as quasi co-located (QCLed) if one or more large-scale properties of the channel over which a first symbol on the first antenna port is conveyed may be inferred from the channel over which a second symbol on a second antenna port is conveyed. The one or more large-scale properties may comprise at least one of: a delay spread; a Doppler spread; a Doppler shift; an average gain; an average delay; and / or spatial Receiving (Rx) parameters.

[0179] Channels that use beamforming require beam management. Beam management may comprise beam measurement, beam selection, and beam indication. A beam may be associated with one or more reference signals. Eor example, a beam may be identified by one or more beamformed reference signals. The UE may perform downlink beam measurement based on downlink reference signals (e.g., a channel state information reference signal (CSI-RS)) and generate a beam measurement report. The UE may perform the downlink beam measurement procedure after an RRC connection is set up with a base station.

[0180] FIG. 11 B illustrates an example of channel state information reference signals (CSI-RSs) that are mapped in the time and frequency domains. A square shown in RIG. 11 B may span a resource block (RB) within a bandwidth of a cell. A base station may transmit one or more RRC messages comprising CSI-RS resource configuration parameters indicating one or more CSI-RSs. One or more of the following parameters may be configured by higher layer signaling (e.g., RRC and / or MAC signaling) for a CSI-RS resource configuration: a CSI-RS resource configuration identity, a number of CSI-RS ports, a CSI-RS configuration (e.g., symbol and resource element (RE) locations in a subframe), a CSI-RS subframe configuration (e.g., subframe location, offset, and periodicity in a radio frame), a CSI-RS power parameter,a CSI-RS sequence parameter, a code division multiplexing (CDM) type parameter, a frequency density, a transmission comb, quasi co-location (QCL) parameters (e.g., QCL-scramblingidentity, crs-portscount, mbsfn-subfrarreconfiglist csi-rs-configZPid, qcl-csi-rs-configNZPid), and / or other radio resource parameters.

[0181] The three beams illustrated in FIG. 11 B may be configured for a UE in a UE-specific configuration. Three beams are illustrated in FIG. 11 B (beam #1 , beam #2, and beam #3), more or fewer beams may be configured. Beam #1 may be allocated with CSI-RS 1101 that may be transmitted in one or more subcarriers in an RB of a first symbol. Beam #2 may be allocated with CSI-RS 1102 that may be transmitted in one or more subcarriers in an RB of a second symbol. Beam #3 may be allocated with CSI- RS 1103 that may be transmitted in one or more subcarriers in an RB of a third symbol. By using frequency division multiplexing (FDM), a base station may use other subcarriers in a same RB (for example, those that are not used to transmit CSI-RS 1101) to transmit another CSI-RS associated with a beam for another UE. By using time domain multiplexing (TDM), beams used for the UE may be configured such that beams for the UE use symbols from beams of other UEs.

[0182] CSI-RSs such as those illustrated in FIG 11 B (e.g., CSI-RS 1101 , 1102, 1103) may be transmitted by the base station and used by the UE for one or more measurements. For example, the UE may measure a reference signal received power (RSRP) of configured CSI-RS resources. The base station may configure the UE with a reporting configuration and the UE may report the RSRP measurements to a network (for example, via one or more base stations) based on the reporting configuration. In an example, the base station may determine, based on the reported measurement results, one or more transmission configuration indication (TCI) states comprising a number of reference signals. In an example, the base station may indicate one or more TCI states to the UE (e.g., via RRC signaling, a MAC CE, and / or a DCI). The UE may receive a downlink transmission with a receive (Rx) beam determined based on the one or more TCI states. In an example, the UE may or may not have a capability of beam correspondence. If the UE has the capability of beam correspondence, the UE may determine a spatial domain filter of a transmit (Tx) beam based on a spatial domain filter of the corresponding Rx beam. If the UE does not have the capability of beam correspondence, the UE may perform an uplink beam selection procedure to determine the spatial domain filter of the Tx beam. The UE may perform the uplink beam selection procedure based on one or more sounding reference signal (SRS) resources configured to the UE by the base station. The base station may select and indicate uplink beams for the UE based on measurements of the one or more SRS resources transmitted by the UE.

[0183] In a beam management procedure, a UE may assess (e.g., measure) a channel quality of one or more beam pair links, a beam pair link comprising a transmitting beam transmitted by a base station and a receiving beam received by the UE. Based on the assessment, the UE may transmit a beam measurementreport indicating one or more beam pair quality parameters comprising, e.g., one or more beam identifications (e.g., a beam index, a reference signal index, or the like), RSRP, a precoding matrix indicator (PMI), a channel quality indicator (CQI), and / or a rank indicator (Rl).

[0184] FIG. 12A illustrates examples of three downlink beam management procedures: P1 , P2, and P3. Procedure P1 may enable a UE measurement on transmit (Tx) beams of a transmission reception point (TRP) (or multiple TRPs), e.g., to support a selection of one or more base station Tx beams and / or UE Rx beams (shown as ovals in the top row and bottom row, respectively, of P1). Beamforming at a TRP may comprise a Tx beam sweep for a set of beams (shown, in the top rows of P1 and P2, as ovals rotated in a counterclockwise direction indicated by the dashed arrow). Beamforming at a UE may comprise an Rx beam sweep for a set of beams (shown, in the bottom rows of P1 and P3, as ovals rotated in a clockwise direction indicated by the dashed arrow). Procedure P2 may be used to enable a UE measurement on Tx beams of a TRP (shown, in the top row of P2, as ovals rotated in a counterclockwise direction indicated by the dashed arrow). The UE and / or the base station may perform procedure P2 using a smaller set of beams than is used in procedure P1 , or using narrower beams than the beams used in procedure P1 . This may be referred to as beam refinement. The UE may perform procedure P3 for Rx beam determination by using the same Tx beam at the base station and sweeping an Rx beam at the UE.

[0185] FIG. 12B illustrates examples of three uplink beam management procedures: U1 , U2, and U3. Procedure U1 may be used to enable a base station to perform a measurement on Tx beams of a UE, e.g., to support a selection of one or more UE Tx beams and / or base station Rx beams (shown as ovals in the top row and bottom row, respectively, of U1). Beamforming at the UE may include, e.g., a Tx beam sweep from a set of beams (shown in the bottom rows of U1 and U3 as ovals rotated in a clockwise direction indicated by the dashed arrow). Beamforming at the base station may include, e.g., an Rx beam sweep from a set of beams (shown, in the top rows of U1 and U2, as ovals rotated in a counterclockwise direction indicated by the dashed arrow). Procedure U2 may be used to enable the base station to adjust its Rx beam when the UE uses a fixed Tx beam. The UE and / or the base station may perform procedure U2 using a smaller set of beams than is used in procedure P1 , or using narrower beams than the beams used in procedure P1 . This may be referred to as beam refinement The UE may perform procedure U3 to adjust its Tx beam when the base station uses a fixed Rx beam.

[0186] A UE may initiate a beam failure recovery (BFR) procedure based on detecting a beam failure. The UE may transmit a BFR request (e.g., a preamble, a UCI, an SR, a MAC CE, and / or the like) based on the initiating of the BFR procedure. The UE may detect the beam failure based on a determination that a quality of beam pair link(s) of an associated control channel is unsatisfactory (e.g., having an error rate higher than an error rate threshold, a received signal power lower than a received signal power threshold, an expiration of a timer, and / or the like).

[0187] The UE may measure a quality of a beam pair link using one or more reference signals (RSs) comprising one or more SS / PBCH blocks, one or more CSI-RS resources, and / or one or more demodulation reference signals (DMRSs). A quality of the beam pair link may be based on one or more of a block error rate (BLER), an RSRP value, a signal to interference plus noise ratio (SINR) value, a reference signal received quality (RSRQ) value, and / or a CSI value measured on RS resources. The base station may indicate that an RS resource is quasi co-located (QCLed) with one or more DM-RSs of a channel (e.g ., a control channel, a shared data channel, and / or the like). The RS resource and the one or more DMRSs of the channel may be QCLed when the channel characteristics (e.g., Doppler shift, Doppler spread, average delay, delay spread, spatial Rx parameter, fading, and / or the like) from a transmission via the RS resource to the UE are similar or the same as the channel characteristics from a transmission via the channel to the UE.

[0188] A network (e.g., a gNB and / or an ng-eNB of a network) and / or the UE may initiate a random access procedure. A UE in an RRCJDLE state and / or an RRCJNACTIVE state may initiate the random access procedure to request a connection setup to a network. The UE may initiate the random access procedure from an RRC_CONNECTED state. The UE may initiate the random access procedure to request uplink resources (e.g., for uplink transmission of an SR when there is no PUCCH resource available) and / or acquire uplink timing (e.g., when uplink synchronization status is non-synchronized). The UE may initiate the random access procedure to request one or more system information blocks (SIBs) (e.g., other system information such as SIB2, SIB3, and / or the like). The UE may initiate the random access procedure for a beam failure recovery request. A network may initiate a random access procedure for a handover and / or for establishing time alignment for an SCell addition.

[0189] FIG. 13A illustrates a four-step contention-based random access procedure. Prior to initiation of the procedure, a base station may transmit a configuration message 1310 to the UE. The procedure illustrated in FIG. 13A comprises transmission of four messages: a Msg 1 1311, a Msg 2 1312, a Msg 3 1313, and a Msg 4 1314. The Msg 1 1311 may include and / or be referred to as a preamble (or a random access preamble). The Msg 2 1312 may include and / or be referred to as a random access response (RAR).

[0190] The configuration message 1310 may be transmitted, for example, using one or more RRC messages The one or more RRC messages may indicate one or more random access channel (RACH) parameters to the UE. The one or more RACH parameters may comprise at least one of following: general parameters for one or more random access procedures (e.g., RACH-configGeneral)', cell-specific parameters (e.g., RACH-ConfigCommon),' and / or dedicated parameters (e.g., RACH-configDedicated) The base station may broadcast or multicast the one or more RRC messages to one or more UEs. The one or more RRC messages may be UE-specific (e.g., dedicated RRC messages transmitted to a UE in an RRC_CONNECTED state and / or in an RRCJNACTIVE state). The UE may determine, based on the oneor more RACH parameters, a time-frequency resource and / or an uplink transmit power for transmission of the Msg 1 1311 and / or the Msg 3 1313. Based on the one or more RACH parameters, the UE may determine a reception timing and a downlink channel for receiving the Msg 2 1312 and the Msg 4 1314.

[0191] The one or more RACH parameters provided in the configuration message 1310 may indicate one or more Physical RACH (PRACH) occasions available for transmission of the Msg 1 1311. The one or more PRACH occasions may be predefined. The one or more RACH parameters may indicate one or more available sets of one or more PRACH occasions (e.g ., prach-Con fig Index). The one or more RACH parameters may indicate an association between (a) one or more PRACH occasions and (b) one or more reference signals. The one or more RACH parameters may indicate an association between (a) one or more preambles and (b) one or more reference signals. The one or more reference signals may be SS / PBCH blocks and / or CSI-RSs. For example, the one or more RACH parameters may indicate a number of SS / PBCH blocks mapped to a PRACH occasion and / or a number of preambles mapped to a SS / PBCH blocks.

[0192] The one or more RACH parameters provided in the configuration message 1310 may be used to determine an uplink transmit power of Msg 1 1311 and / or Msg 3 1313. For example, the one or more RACH parameters may indicate a reference power for a preamble transmission (e.g., a received target power and / or an initial power of the preamble transmission). There may be one or more power offsets indicated by the one or more RACH parameters. For example, the one or more RACH parameters may indicate: a power ramping step; a power offset between SSB and CSI-RS; a power offset between transmissions of the Msg 1 1311 and the Msg 3 1313; and / or a power offset value between preamble groups. The one or more RACH parameters may indicate one or more thresholds based on which the UE may determine at least one reference signal (e.g., an SSB and / or CSI-RS) and / or an uplink carrier (e.g., a normal uplink (NUL) carrier and / or a supplemental uplink (SUL) carrier).

[0193] The Msg 1 1311 may include one or more preamble transmissions (e.g., a preamble transmission and one or more preamble retransmissions). An RRC message may be used to configure one or more preamble groups (e.g., group A and / or group B). A preamble group may comprise one or more preambles. The UE may determine the preamble group based on a pathloss measurement and / or a size of the Msg 3 1313. The UE may measure an RSRP of one or more reference signals (e.g., SSBs and / or CSI-RSs) and determine at least one reference signal having an RSRP above an RSRP threshold (e.g., rsrp- ThresholdSSB and / or rsrp-ThresholdCSI-RS). The UE may select at least one preamble associated with the one or more reference signals and / or a selected preamble group, for example, if the association between the one or more preambles and the at least one reference signal is configured by an RRC message.

[0194] The UE may determine the preamble based on the one or more RACH parameters provided in the configuration message 1310. For example, the UE may determine the preamble based on a pathloss measurement, an RSRP measurement, and / or a size of the Msg 3 1313. As another example, the one or more RACH parameters may indicate: a preamble format; a maximum number of preamble transmissions; and / or one or more thresholds for determining one or more preamble groups (e.g . , group A and group B). A base station may use the one or more RACH parameters to configure the UE with an association between one or more preambles and one or more reference signals (e.g., SSBs and / or CSI-RSs). If the association is configured, the UE may determine the preamble to include in Msg 1 1311 based on the association. The Msg 1 1311 may be transmitted to the base station via one or more PRACH occasions. The UE may use one or more reference signals (e.g., SSBs and / or CSI-RSs) for selection of the preamble and for determining of the PRACH occasion. One or more RACH parameters (e.g., ra-ssb-OccasionMsklndex and / or ra-OccasionList) may indicate an association between the PRACH occasions and the one or more reference signals.

[0195] The UE may perform a preamble retransmission if no response is received following a preamble transmission. The UE may increase an uplink transmit power for the preamble retransmission. The UE may select an initial preamble transmit power based on a pathloss measurement and / or a target received preamble power configured by the network. The UE may determine to retransmit a preamble and may ramp up the uplink transmit power. The UE may receive one or more RACH parameters (e.g., PREAMBLE_POWER_RAMPING_STEP) indicating a ramping step for the preamble retransmission The ramping step may be an amount of incremental increase in uplink transmit power for a retransmission. The UE may ramp up the uplink transmit power if the UE determines a reference signal (e.g., SSB and / or CSI- RS) that is the same as a previous preamble transmission. The UE may count a number of preamble transmissions and / or retransmissions (e.g., PREAMBLE_TRANSMISSION_COUNTER). The UE may determine that a random access procedure completed unsuccessfully, for example, if the number of preamble transmissions exceeds a threshold configured by the one or more RACH parameters (e.g., preambleTransMax) .

[0196] The Msg 2 1312 received by the UE may include an RAR. In some scenarios, the Msg 2 1312 may include multiple RARs corresponding to multiple UEs The Msg 2 1312 may be received after or in response to the transmitting of the Msg 1 1311. The Msg 2 1312 may be scheduled on the DL-SCH and indicated on a PDCCH using a random access RNTI (RA-RNTI). The Msg 2 1312 may indicate that the Msg 1 1311 was received by the base station. The Msg 2 1312 may include a time-alignment command that may be used by the UE to adjust the UE’s transmission timing, a scheduling grant for transmission of the Msg 3 1313, and / or a Temporary Cell RNTI (TC-RNTI). After transmitting a preamble, the UE may start a time window (e.g., ra-ResponseWindow) to monitor a PDCCH for the Msg 2 1312. The UE maydetermine when to start the time window based on a PRACH occasion that the UE uses to transmit the preamble. For example, the UE may start the time window one or more symbols after a last symbol of the preamble (e.g., at a first PDCCH occasion from an end of a preamble transmission). The one or more symbols may be determined based on a numerology. The PDCCH may be in a common search space (e.g., a Typel-PDCCH common search space) configured by an RRC message. The UE may identify the RAR based on a Radio Network Temporary Identifier (RNTI). RNTIs may be used depending on one or more events initiating the random access procedure. The UE may use random access RNTI (RA-RNTI). The RA-RNTI may be associated with PRACH occasions in which the UE transmits a preamble. For example, the UE may determine the RA-RNTI based on: an OFDM symbol index; a slot index; a frequency domain index; and / or a UL carrier indicator of the PRACH occasions. An example of RA-RNTI may be as follows:

[0197] RA-RNTI= 1 + s_id + 14 x t_id + 14 x 80 x fjd + 14 x 80 x 8 x ul_carrier_id , where s_id may be an index of a first OFDM symbol of the PRACH occasion (e.g., 0 < sjd < 14), t_id may be an index of a first slot of the PRACH occasion in a system frame (e.g., 0 < t_id < 80), f_id may be an index of the PRACH occasion in the frequency domain (e.g., 0 < f_id < 8), and ul_carrier_id may be a UL carrier used for a preamble transmission (e.g., 0 for an NUL carrier, and 1 for an SUL carrier).

[0198] The UE may transmit the Msg 3 1313 in response to a successful reception of the Msg 2 1312 (e.g., using resources identified in the Msg 2 1312). The Msg 3 1313 may be used for contention resolution in, for example, the contention-based random access procedure illustrated in FIG. 13A. In some scenarios, a plurality of UEs may transmit a same preamble to a base station and the base station may provide an RAR that corresponds to a UE. Collisions may occur if the plurality of UEs interpret the RAR as corresponding to themselves. Contention resolution (e.g., using the Msg 3 1313 and the Msg 4 1314) may be used to increase the likelihood that the UE does not incorrectly use an identity of another the UE. To perform contention resolution, the UE may include a device identifier in the Msg 3 1313 (e.g , a C-RNTI if assigned, a TC-RNTI included in the Msg 2 1312, and / or any other suitable identifier).

[0199] The Msg 4 1314 may be received after or in response to the transmitting of the Msg 3 1313. If a C-RNTI was included in the Msg 3 1313, the base station will address the UE on the PDCCH using the C-RNTI. If the UE's unique C-RNTI is detected on the PDCCH, the random access procedure is determined to be successfully completed. If a TC-RNTI is included in the Msg 3 1313 (e.g., if the UE is in an RRCJDLE state or not otherwise connected to the base station), Msg 4 1314 will be received using a DL-SCH associated with the TC-RNTI. If a MAC PDU is successfully decoded and a MAC PDU comprises the UE contention resolution identity MAC CE that matches or otherwise corresponds with the CCCH SDU sent (e.g., transmitted) in Msg 3 1313, the UE may determine that the contention resolution is successful and / or the UE may determine that the random access procedure is successfully completed.

[0200] The UE may be configured with a supplementary uplink (SUL) carrier and a normal uplink (NUL) carrier. An initial access (e.g., random access procedure) may be supported in an uplink carrier. For example, a base station may configure the UE with two separate RACH configurations: one for an SUL carrier and the other for an NUL carrier. For random access in a cell configured with an SUL carrier, the network may indicate which carrier to use (NUL or SUL). The UE may determine the SUL carrier, for example, if a measured quality of one or more reference signals is lower than a broadcast threshold. Uplink transmissions of the random access procedure (e.g., the Msg 1 1311 and / or the Msg 3 1313) may remain on the selected carrier. The UE may switch an uplink carrier during the random access procedure (e.g., between the Msg 1 1311 and the Msg 3 1313) in one or more cases. For example, the UE may determine and / or switch an uplink carrier for the Msg 1 1311 and / or the Msg 3 1313 based on a channel clear assessment (e.g., a listen-before-talk).

[0201] FIG. 13B illustrates a two-step contention-free random access procedure. Similar to the four-step contention-based random access procedure illustrated in FIG. 13A, a base station may, prior to initiation of the procedure, transmit a configuration message 1320 to the UE. The configuration message 1320 may be analogous in some respects to the configuration message 1310. The procedure illustrated in FIG. 13B comprises transmission of two messages: a Msg 1 1321 and a Msg 2 1322. The Msg 1 1321 and the Msg 2 1322 may be analogous in some respects to the Msg 1 1311 and a Msg 2 1312 illustrated in FIG. 13A, respectively. As will be understood from FIGS. 13A and 13B, the contention-free random access procedure may not include messages analogous to the Msg 3 1313 and / or the Msg 4 1314.

[0202] The contention-free random access procedure illustrated in FIG. 13B may be initiated for a beam failure recovery, other SI request, SCell addition, and / or handover. For example, a base station may indicate or assign to the UE the preamble to be used for the Msg 1 1321 . The UE may receive, from the base station via PDCCH and / or RRC, an indication of a preamble (e.g., ra-Preamblelndex).

[0203] After transmitting a preamble, the UE may start a time window (e.g., ra-ResponseWindow) to monitor a PDCCH for the RAR. In the event of a beam failure recovery request, the base station may configure the UE with a separate time window and / or a separate PDCCH in a search space indicated by an RRC message (e.g., recovery SearchSpaceld). The UE may monitor for a PDCCH transmission addressed to a Cell RNTI (C-RNTI) on the search space. In the contention-free random access procedure illustrated in FIG. 13B, the UE may determine that a random access procedure successfully completes after or in response to transmission of Msg 1 1321 and reception of a corresponding Msg 2 1322. The UE may determine that a random access procedure successfully completes, for example, if a PDCCH transmission is addressed to a C-RNTI. The UE may determine that a random access procedure successfully completes, for example, if the UE receives an RAR comprising a preamble identifier corresponding to a preambletransmitted by the UE and / or the RAR comprises a MAC sub-PDU with the preamble identifier. The UE may determine the response as an indication of an acknowledgement for an SI request.

[0204] FIG. 13C illustrates another two-step random access procedure. Similar to the random access procedures illustrated in FIGS. 13A and 13B, a base station may, prior to initiation of the procedure, transmit a configuration message 1330 to the UE. The configuration message 1330 may be analogous in some respects to the configuration message 1310 and / or the configuration message 1320. The procedure illustrated in FIG. 13C comprises transmission of two messages: a Msg A 1331 and a Msg B 1332.

[0205] Msg A 1331 may be transmitted in an uplink transmission by the UE. Msg A 1331 may comprise one or more transmissions of a preamble 1341 and / or one or more transmissions of a transport block 1342. The transport block 1342 may comprise contents that are similar and / or equivalent to the contents of the Msg 3 1313 illustrated in FIG. 13A. The transport block 1342 may comprise UCI (e.g., an SR, a HARQ ACK / NACK, and / or the like). The UE may receive the Msg B 1332 after or in response to transmitting the Msg A 1331 . The Msg B 1332 may comprise contents that are similar and / or equivalent to the contents of the Msg 2 1312 (e.g., an RAR) illustrated in FIGS. 13A and 13B and / or the Msg 4 1314 illustrated in FIG. 13A.

[0206] The UE may initiate the two-step random access procedure in FIG. 13C for licensed spectrum and / or unlicensed spectrum. The UE may determine, based on one or more factors, whether to initiate the two-step random access procedure. The one or more factors may be: a radio access technology in use (e.g , LTE, NR, and / or the like); whether the UE has valid TA or not; a cell size; the UE's RRC state; a type of spectrum (e.g., licensed vs. unlicensed); and / or any other suitable factors.

[0207] The UE may determine, based on two-step RACH parameters included in the configuration message 1330, a radio resource and / or an uplink transmit power for the preamble 1341 and / or the transport block 1342 included in the Msg A 1331. The RACH parameters may indicate a modulation and coding schemes (MCS), a time-frequency resource, and / or a power control for the preamble 1341 and / or the transport block 1342. A time-frequency resource for transmission of the preamble 1341 (e.g., a PRACH) and a time-frequency resource for transmission of the transport block 1342 (e.g., a PUSCH) may be multiplexed using EDM, TDM, and / or CDM. The RACH parameters may enable the UE to determine a reception timing and a downlink channel for monitoring for and / or receiving Msg B 1332.

[0208] The transport block 1342 may comprise data (e.g., delay-sensitive data), an identifier of the UE, security information, and / or device information (e.g., an International Mobile Subscriber Identity (IMSI)). The base station may transmit the Msg B 1332 as a response to the Msg A 1331 . The Msg B 1332 may comprise at least one of following: a preamble identifier; a timing advance command; a power control command; an uplink grant (e.g., a radio resource assignment and / or an MCS); a UE identifier for contention resolution; and / or an RNTI (e.g., a C-RNTI or a TC-RNTI). The UE may determine that the two-steprandom access procedure is successfully completed if: a preamble identifier in the Msg B 1332 is matched to a preamble transmitted by the UE; and / or the identifier of the UE in Msg B 1332 is matched to the identifier of the UE in the Msg A 1331 (e.g., the transport block 1342).

[0209] A UE and a base station may exchange control signaling. The control signaling may be referred to as L1 / L2 control signaling and may originate from the PHY layer (e.g., layer 1) and / or the MAC layer (e.g., layer 2). The control signaling may comprise downlink control signaling transmitted from the base station to the UE and / or uplink control signaling transmitted from the UE to the base station.

[0210] The downlink control signaling may comprise: a downlink scheduling assignment; an uplink scheduling grant indicating uplink radio resources and / or a transport format; a slot format information; a preemption indication; a power control command; and / or any other suitable signaling. The UE may receive the downlink control signaling in a payload transmitted by the base station on a physical downlink control channel (PDCCH). The payload transmitted on the PDCCH may be referred to as downlink control information (DCI). In some scenarios, the PDCCH may be a group common PDCCH (GC-PDCCH) that is common to a group of UEs.

[0211] A base station may attach one or more cyclic redundancy check (CRC) parity bits to a DCI in order to facilitate detection of transmission errors. When the DCI is intended for a UE (or a group of the UEs), the base station may scramble the CRC parity bits with an identifier of the UE (or an identifier of the group of the UEs). Scrambling the CRC parity bits with the identifier may comprise Modulo-2 addition (or an exclusive OR operation) of the identifier value and the CRC parity bits. The identifier may comprise a 16-bit value of a radio network temporary identifier (RNTI).

[0212] DCIs may be used for different purposes. A purpose may be indicated by the type of RNTI used to scramble the CRC parity bits. For example, a DCI having CRC parity bits scrambled with a paging RNTI (P- RNTI) may indicate paging information and / or a system information change notification. The P-RNTI may be predefined as "FFFE” in hexadecimal. A DCI having CRC parity bits scrambled with a system information RNTI (SI-RNTI) may indicate a broadcast transmission of the system information. The SI-RNTI may be predefined as “FFFF” in hexadecimal. A DCI having CRC parity bits scrambled with a random access RNTI (RA-RNTI) may indicate a random access response (RAR). A DCI having CRC parity bits scrambled with a cell RNTI (C-RNTI) may indicate a dynamically scheduled unicast transmission and / or a triggering of PDCCH-ordered random access. A DCI having CRC parity bits scrambled with a temporary cell RNTI (TC-RNTI) may indicate a contention resolution (e.g., a Msg 3 analogous to the Msg 3 1313 illustrated in FIG. 13A). Other RNTIs configured to the UE by a base station may comprise a Configured Scheduling RNTI (CS-RNTI), a Transmit Power Control-PUCCH RNTI (TPC-PUCCH-RNTI), a Transmit Power Control-PUSCH RNTI (TPC-PUSCH-RNTI), a Transmit Power Control-SRS RNTI (TPC-SRS-RNTI),an Interruption RNTI (INT-RNTI), a Slot Format Indication RNTI (SFI-RNTI), a Semi-Persistent CSI RNTI (SP-CSI-RNTI), a Modulation and Coding Scheme Cell RNTI (MCS-C-RNTI), and / or the like.

[0213] Depending on the purpose and / or content of a DCI, the base station may transmit the DCIs with one or more DCI formats. For example, DCI format 0_0 may be used for scheduling of PUSCH in a cell. DCI format 0_0 may be a fallback DCI format (e.g., with compact DCI payloads). DCI format 0_1 may be used for scheduling of PUSCH in a cell (e.g., with more DCI payloads than DCI format 0_0). DCI format 1_0 may be used for scheduling of PDSCH in a cell. DCI format 1_0 may be a fallback DCI format (e.g., with compact DCI payloads). DCI format 1_1 may be used for scheduling of PDSCH in a cell (e.g., with more DCI payloads than DCI format 1 _0) . DCI format 2_0 may be used for providing a slot format indication to a group of UEs. DCI format 2_1 may be used for notifying a group of UEs of a physical resource block and / or OFDM symbol where the UE may assume no transmission is intended to the UE. DCI format 2_2 may be used for transmission of a transmit power control (TPC) command for PUCCH or PUSCH. DCI format 2_3 may be used for transmission of a group of TPC commands for SRS transmissions by one or more UEs. DCI format(s) for new functions may be defined in future releases. DCI formats may have different DCI sizes, or may share the same DCI size.

[0214] After scrambling a DCI with a RNTI, the base station may process the DCI with channel coding (e.g., polar coding), rate matching, scrambling and / or QPSK modulation. A base station may map the coded and modulated DCI on resource elements used and / or configured for a PDCCH. Based on a payload size of the DCI and / or a coverage of the base station, the base station may transmit the DCI via a PDCCH occupying a number of contiguous control channel elements (CCEs). The number of the contiguous CCEs (referred to as aggregation level) may be 1 , 2, 4, 8, 16, and / or any other suitable number. A CCE may comprise a number (e.g., 6) of resource-element groups (REGs). A REG may comprise a resource block in an OFDM symbol. The mapping of the coded and modulated DCI on the resource elements may be based on mapping of CCEs and REGs (e.g., CCE-to-REG mapping).

[0215] FIG. 14A illustrates an example of CORESET configurations for a bandwidth part. The base station may transmit a DCI via a PDCCH on one or more control resource sets (CORESETs). A CORESET may comprise a time-frequency resource in which the UE tries to decode a DCI using one or more search spaces. The base station may configure a CORESET in the time-frequency domain. In the example of FIG. 14A, a first CORESET 1401 and a second CORESET 1402 occur at the first symbol in a slot. The first CORESET 1401 overlaps with the second CORESET 1402 in the frequency domain. A third CORESET 1403 occurs at a third symbol in the slot. A fourth CORESET 1404 occurs at the seventh symbol in the slot. CORESETs may have a different number of resource blocks in frequency domain.

[0216] FIG. 14B illustrates an example of a CCE-to-REG mapping for DCI transmission on a CORESET and PDCCH processing. The CCE-to-REG mapping may be an interleaved mapping (e.g., for the purposeof providing frequency diversity) or a non-interleaved mapping (e.g., for the purposes of facilitating interference coordination and / or frequency-selective transmission of control channels). The base station may perform different or same CCE-to-REG mapping on different CORESETs. A CORESET may be associated with a CCE-to-REG mapping by RRC configuration. A CORESET may be configured with an antenna port quasi co-location (QCL) parameter. The antenna port QCL parameter may indicate QCL information of a demodulation reference signal (DMRS) for PDCCH reception in the CORESET.

[0217] The base station may transmit, to the UE, RRC messages comprising configuration parameters of one or more CORESETs and one or more search space sets. The configuration parameters may indicate an association between a search space set and a CORESET. A search space set may comprise a set of PDCCH candidates formed by CCEs at a given aggregation level. The configuration parameters may indicate: a number of PDCCH candidates to be monitored per aggregation level; a PDCCH monitoring periodicity and a PDCCH monitoring pattern; one or more DCI formats to be monitored by the UE; and / or whether a search space set is a common search space set or a UE-specific search space set. A set of CCEs in the common search space set may be predefined and known to the UE. A set of CCEs in the UE- specific search space set may be configured based on the UE's identity (e.g., C-RNTI).

[0218] As shown in FIG. 14B, the UE may determine a time-frequency resource for a CORESET based on RRC messages. The UE may determine a CCE-to-REG mapping (e.g., interleaved or non-interleaved, and / or mapping parameters) for the CORESET based on configuration parameters of the CORESET. The UE may determine a number (e.g., at most 10) of search space sets configured on the CORESET based on the RRC messages. The UE may monitor a set of PDCCH candidates according to configuration parameters of a search space set. The UE may monitor a set of PDCCH candidates in one or more CORESETs for detecting one or more DCIs. Monitoring may comprise decoding one or more PDCCH candidates of the set of the PDCCH candidates according to the monitored DCI formats. Monitoring may comprise decoding a DCI content of one or more PDCCH candidates with possible (or configured) PDCCH locations, possible (or configured) PDCCH formats (e.g., number of CCEs, number of PDCCH candidates in common search spaces, and / or number of PDCCH candidates in the UE-specific search spaces) and possible (or configured) DCI formats. The decoding may be referred to as blind decoding. The UE may determine a DCI as valid for the UE, in response to CRC checking (e.g., scrambled bits for CRC parity bits of the DCI matching a RNTI value). The UE may process information contained in the DCI (e.g., a scheduling assignment, an uplink grant, power control, a slot format indication, a downlink preemption, and / or the like).

[0219] The UE may transmit uplink control signaling (e.g., uplink control information (UCI)) to a base station. The uplink control signaling may comprise hybrid automatic repeat request (HARQ) acknowledgements for received DL-SCH transport blocks. The UE may transmit the HARQacknowledgements after receiving a DL-SCH transport block. Uplink control signaling may comprise channel state information (CSI) indicating channel quality of a physical downlink channel. The UE may transmit the CSI to the base station. The base station, based on the received CSI, may determine transmission format parameters (e.g., comprising multi-antenna and beamforming schemes) for a downlink transmission. Uplink control signaling may comprise scheduling requests (SR). The UE may transmit an SR indicating that uplink data is available for transmission to the base station. The UE may transmit a UCI (e.g., HARQ acknowledgements (HARQ-ACK), CSI report, SR, and the like) via a physical uplink control channel (PUCCH) or a physical uplink shared channel (RUSCH). The UE may transmit the uplink control signaling via a PUCCH using one of several PUCCH formats.

[0220] There may be five PUCCH formats and the UE may determine a PUCCH format based on a size of the UCI (e.g., a number of uplink symbols of UCI transmission and a number of UCI bits). PUCCH format 0 may have a length of one or two OFDM symbols and may include two or fewer bits. The UE may transmit UCI in a PUCCH resource using PUCCH format 0 if the transmission is over one or two symbols and the number of HARQ-ACK information bits with positive or negative SR (HARQ-ACK / SR bits) is one or two. PUCCH format 1 may occupy a number between four and fourteen OFDM symbols and may include two or fewer bits. The UE may use PUCCH format 1 if the transmission is four or more symbols and the number of HARQ-ACK / SR bits is one or two. PUCCH format 2 may occupy one or two OFDM symbols and may include more than two bits. The UE may use PUCCH format 2 if the transmission is over one or two symbols and the number of UCI bits is two or more. PUCCH format 3 may occupy a number between four and fourteen OFDM symbols and may include more than two bits. The UE may use PUCCH format 3 if the transmission is four or more symbols, the number of UCI bits is two or more and PUCCH resource does not include an orthogonal cover code. PUCCH format 4 may occupy a number between four and fourteen OFDM symbols and may include more than two bits. The UE may use PUCCH format 4 if the transmission is four or more symbols, the number of UCI bits is two or more and the PUCCH resource includes an orthogonal cover code.

[0221] The base station may transmit configuration parameters to the UE for a plurality of PUCCH resource sets using, for example, an RRC message. The plurality of PUCCH resource sets (e.g., up to four sets) may be configured on an uplink BWP of a cell. A PUCCH resource set may be configured with a PUCCH resource set index, a plurality of PUCCH resources with a PUCCH resource being identified by a PUCCH resource identifier (e.g., pucch-Resourceid), and / or a number (e.g., a maximum number) of UCI information bits the UE may transmit using one of the plurality of PUCCH resources in the PUCCH resource set. When configured with a plurality of PUCCH resource sets, the UE may select one of the plurality of PUCCH resource sets based on a total bit length of the UCI information bits (e.g., HARQ-ACK, SR, and / or CSI). If the total bit length of UCI information bits is two or fewer, the UE may select a firstPUCCH resource set having a PUCCH resource set index equal to "0” If the total bit length of UCI information bits is greater than two and less than or equal to a first configured value, the UE may select a second PUCCH resource set having a PUCCH resource set index equal to “1”. If the total bit length of UCI information bits is greater than the first configured value and less than or equal to a second configured value, the UE may select a third PUCCH resource set having a PUCCH resource set index equal to “2". If the total bit length of UCI information bits is greater than the second configured value and less than or equal to a third value (e.g., 1406), the UE may select a fourth PUCCH resource set having a PUCCH resource set index equal to “3”.

[0222] After determining a PUCCH resource set from a plurality of PUCCH resource sets, the UE may determine a PUCCH resource from the PUCCH resource set for UCI (HARQ-ACK, CSI, and / or SR) transmission. The UE may determine the PUCCH resource based on a PUCCH resource indicator in a DCI (e.g., with a DCI format 1_0 or DCI for 1_1) received on a PDCCH. A three-bit PUCCH resource indicator in the DCI may indicate one of eight PUCCH resources in the PUCCH resource set. Based on the PUCCH resource indicator, the UE may transmit the UCI (HARQ-ACK, CSI and / or SR) using a PUCCH resource indicated by the PUCCH resource indicator in the DCI.

[0223] FIG. 15 illustrates an example of a wireless device 1502 in communication with a base station 1504 in accordance with embodiments of the present disclosure. The wireless device 1502 and base station 1504 may be part of a mobile communication network, such as the mobile communication network 100 illustrated in FIG. 1A, the mobile communication network 150 illustrated in FIG. 1 B, or any other communication network. Only one wireless device 1502 and one base station 1504 are illustrated in FIG. 15, but it will be understood that a mobile communication network may include more than one UE and / or more than one base station, with the same or similar configuration as those shown in FIG. 15.

[0224] The base station 1504 may connect the wireless device 1502 to a core network (not shown) through radio communications over the air interface (or radio interface) 1506. The communication direction from the base station 1504 to the wireless device 1502 over the air interface 1506 is known as the downlink, and the communication direction from the wireless device 1502 to the base station 1504 over the air interface is known as the uplink. Downlink transmissions may be separated from uplink transmissions using FDD, TDD, and / or some combination of the two duplexing techniques.

[0225] In the downlink, data to be sent to the wireless device 1502 from the base station 1504 may be provided to the processing system 1508 of the base station 1504. The data may be provided to the processing system 1508 by, for example, a core network. In the uplink, data to be sent to the base station 1504 from the wireless device 1502 may be provided to the processing system 1518 of the wireless device 1502. The processing system 1508 and the processing system 1518 may implement layer 3 and layer 2 OSI functionality to process the data for transmission. Layer 2 may include an SDAP layer, a PDCP layer,an RLC layer, and a MAC layer, for example, with respect to FIG. 2A, FIG. 2B, FIG. 3, and FIG. 4A. Layer 3 may include an RRC layer as with respect to FIG. 2B.

[0226] After being processed by processing system 1508, the data to be sent to the wireless device 1502 may be provided to a transmission processing system 1510 of base station 1504. Similarly, after being processed by the processing system 1518, the data to be sent to base station 1504 may be provided to a transmission processing system 1520 of the wireless device 1502. The transmission processing system 1510 and the transmission processing system 1520 may implement layer 1 OSI functionality. Layer 1 may include a PHY layer with respect to FIG. 2A, FIG. 2B, FIG. 3, and FIG. 4A. For transmit processing, the PHY layer may perform, for example, forward error correction coding of transport channels, interleaving, rate matching, mapping of transport channels to physical channels, modulation of physical channel, multiple-input multiple-output (MIMO) or multi-antenna processing, and / or the like.

[0227] At the base station 1504, a reception processing system 1512 may receive the uplink transmission from the wireless device 1502. At the wireless device 1502, a reception processing system 1522 may receive the downlink transmission from base station 1504. The reception processing system 1512 and the reception processing system 1522 may implement layer 1 OSI functionality. Layer 1 may include a PHY layer with respect to FIG. 2A, FIG. 2B, FIG. 3, and FIG. 4A. For receive processing, the PHY layer may perform, for example, error detection, forward error correction decoding, deinterleaving, demapping of transport channels to physical channels, demodulation of physical channels, MIMO or multi-antenna processing, and / or the like.

[0228] As shown in FIG. 15, a wireless device 1502 and the base station 1504 may include multiple antennas. The multiple antennas may be used to perform one or more MIMO or multi-antenna techniques, such as spatial multiplexing (e.g., single-user MIMO or multi-user MIMO), transmit / receive diversity, and / or beamforming. In other examples, the wireless device 1502 and / or the base station 1504 may have a single antenna

[0229] The processing system 1508 and the processing system 1518 may be associated with a memory 1514 and a memory 1524, respectively. Memory 1514 and memory 1524 (e.g., one or more non-transitory computer readable mediums) may store computer program instructions or code that may be executed by the processing system 1508 and / or the processing system 1518 to carry out one or more of the functionalities discussed in the present application. Although not shown in FIG. 15, the transmission processing system 1510, the transmission processing system 1520, the reception processing system 1512, and / or the reception processing system 1522 may be coupled to a memory (e.g., one or more non- transitory computer readable mediums) storing computer program instructions or code that may be executed to carry out one or more of their respective functionalities.

[0230] The processing system 1508 and / or the processing system 1518 may comprise one or more controllers and / or one or more processors. The one or more controllers and / or one or more processors may comprise, for example, a general-purpose processor, a digital signal processor (DSP), a microcontroller, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) and / or other programmable logic device, discrete gate and / or transistor logic, discrete hardware components, an onboard unit, or any combination thereof. The processing system 1508 and / or the processing system 1518 may perform at least one of signal coding / processing, data processing, power control, input / output processing, and / or any other functionality that may enable the wireless device 1502 and the base station 1504 to operate in a wireless environment.

[0231] The processing system 1508 and / or the processing system 1518 may be connected to one or more peripherals 1516 and one or more peripherals 1526, respectively. The one or more peripherals 1516 and the one or more peripherals 1526 may include software and / or hardware that provide features and / or functionalities, for example, a speaker, a microphone, a keypad, a display, a touchpad, a power source, a satellite transceiver, a universal serial bus (USB) port, a hands-free headset, a frequency modulated (FM) radio unit, a media player, an Internet browser, an electronic control unit (e.g., for a motor vehicle), and / or one or more sensors (e.g., an accelerometer, a gyroscope, a temperature sensor, a radar sensor, a lidar sensor, an ultrasonic sensor, a light sensor, a camera, and / or the like). The processing system 1508 and / or the processing system 1518 may receive user input data from and / or provide user output data to the one or more peripherals 1516 and / or the one or more peripherals 1526 The processing system 1518 in the wireless device 1502 may receive power from a power source and / or may be configured to distribute the power to the other components in the wireless device 1502. The power source may comprise one or more sources of power, for example, a battery, a solar cell, a fuel cell, or any combination thereof. The processing system 1508 and / or the processing system 1518 may be connected to a GPS chipset 1517 and a GPS chipset 1527, respectively. The GPS chipset 1517 and the GPS chipset 1527 may be configured to provide geographic location information of the wireless device 1502 and the base station 1504, respectively.

[0232] FIG. 16A illustrates an example structure for uplink transmission. A baseband signal representing a physical uplink shared channel may perform one or more functions. The one or more functions may comprise at least one of: scrambling; modulation of scrambled bits to generate complex-valued symbols; mapping of the complex-valued modulation symbols onto one or several transmission layers; transform precoding to generate complex-valued symbols; precoding of the complex-valued symbols; mapping of precoded complex-valued symbols to resource elements; generation of complex-valued time-domain Single Carrier-Frequency Division Multiple Access (SC-FDMA) or CP-OFDM signal for an antenna port; and / or the like. In an example, when transform precoding is enabled, a SC-FDMA signal for uplink transmission maybe generated. In an example, when transform precoding is not enabled, a CP-OFDM signal for uplink transmission may be generated by FIG. 16A. These functions are illustrated as examples and it is anticipated that other mechanisms may be implemented in various embodiments.

[0233] FIG. 16B illustrates an example structure for modulation and up-conversion of a baseband signal to a carrier frequency. The baseband signal may be a complex-valued SC-FDMA or CP-OFDM baseband signal for an antenna port and / or a complex-valued Physical Random Access Channel (PRACH) baseband signal. Filtering may be employed prior to transmission.

[0234] FIG. 16C illustrates an example structure for downlink transmissions. A baseband signal representing a physical downlink channel may perform one or more functions. The one or more functions may comprise: scrambling of coded bits in a codeword to be transmitted on a physical channel; modulation of scrambled bits to generate complex-valued modulation symbols; mapping of the complex-valued modulation symbols onto one or several transmission layers; precoding of the complex-valued modulation symbols on a layer for transmission on the antenna ports; mapping of complex-valued modulation symbols for an antenna port to resource elements; generation of complex-valued time-domain OFDM signal for an antenna port; and / or the like. These functions are illustrated as examples and it is anticipated that other mechanisms may be implemented in various embodiments.

[0235] FIG. 16D illustrates another example structure for modulation and up-conversion of a baseband signal to a carrier frequency. The baseband signal may be a complex-valued OFDM baseband signal for an antenna port. Filtering may be employed prior to transmission.

[0236] A wireless device may receive from a base station one or more messages (e.g., RRC messages) comprising configuration parameters of a plurality of cells (e.g., primary cell, secondary cell). The wireless device may communicate with at least one base station (e.g., two or more base stations in dual connectivity) via the plurality of cells. The one or more messages (e.g., as a part of the configuration parameters) may comprise parameters of physical, MAC, RLC, PCDP, SDAP, RRC layers for configuring the wireless device. For example, the configuration parameters may comprise parameters for configuring physical and MAC layer channels, bearers, etc. For example, the configuration parameters may comprise parameters indicating values of timers for physical, MAC, RLC, PCDP, SDAP, RRC layers, and / or communication channels.

[0237] A timer may begin running once it is started and continue running until it is stopped or until it expires. A timer may be started if it is not running or restarted if it is running. A timer may be associated with a value (e.g., the timer may be started or restarted from a value or may be started from zero and expire once it reaches the value). The duration of a timer may not be updated until the timer is stopped or expires (e.g., due to BWP switching). A timer may be used to measure a time period / window for a process. When the specification refers to an implementation and procedure related to one or more timers, it will beunderstood that there are multiple ways to implement the one or more timers For example, it will be understood that one or more of the multiple ways to implement a timer may be used to measure a time period / window for the procedure. For example, a random access response window timer may be used for measuring a window of time for receiving a random access response. In an example, instead of starting and expiry (or expiration) of a random access response window timer, the time difference between two time stamps may be used. When a timer is restarted, a process for measurement of time window may be restarted. Other example implementations may be provided to restart a measurement of a time window.

[0238] A base station may transmit one or more MAC PDUs to a wireless device. In an example, a MAC PDU may be a bit string that is byte aligned (e.g., aligned to a multiple of eight bits) in length. In an example, bit strings may be represented by tables in which the most significant bit is the leftmost bit of the first line of the table, and the least significant bit is the rightmost bit on the last line of the table. More generally, the bit string may be read from left to right and then in the reading order of the lines. In an example, the bit order of a parameter field within a MAC PDU is represented with the first and most significant bit in the leftmost bit and the last and least significant bit in the rightmost bit.

[0239] In an example, a MAC SDU may be a bit string that is byte aligned (e.g., aligned to a multiple of eight bits) in length. In an example, a MAC SDU may be included in a MAC PDU from the first bit onward. A MAC CE may be a bit string that is byte aligned (e.g., aligned to a multiple of eight bits) in length. A MAC subheader may be a bit string that is byte aligned (e.g., aligned to a multiple of eight bits) in length. In an example, a MAC subheader may be placed immediately in front of a corresponding MAC SDU, MAC CE, or padding. A MAC entity may ignore the value of reserved bits in a DL MAC PDU.

[0240] In an example, a MAC PDU may comprise one or more MAC subPDUs. A MAC subPDU of the one or more MAC subPDUs may comprise: a MAC subheader only (including padding); a MAC subheader and a MAC SDU; a MAC subheader and a MAC CE; a MAC subheader and padding, or a combination thereof. The MAC SDU may be of variable size. A MAC subheader may correspond to a MAC SDU, a MAC CE, or padding.

[0241] In an example, when a MAC subheader corresponds to a MAC SDU, a variable-sized MAC CE, or padding, the MAC subheader may comprise: an R field with a one-bit length; an F field with a one-bit length; an LCID field with a multi-bit length; an L field with a multi-bit length, or a combination thereof.

[0242] FIG. 17A shows an example of a MAC subheader with an R field, an F field, an LCID field, and an L field. In the example MAC subheader of FIG. 17A, the LCID field may be six bits in length, and the L field may be eight bits in length. FIG. 17B shows an example of a MAC subheader with an R field, an F field, an LCID field, and an L field. In the example MAC subheader shown in FIG. 17B, the LCID field may be six bits in length, and the L field may be sixteen bits in length When a MAC subheader corresponds to a fixed sized MAC CE or padding, the MAC subheader may comprise: an R field with a two-bit length and an LCIDfield with a multi-bit length. FIG. 17C shows an example of a MAC subheader with an R field and an LCID field. In the example MAC subheader shown in FIG. 17C, the LCID field may be six bits in length, and the R field may be two bits in length.

[0243] FIG. 18A shows an example of a DL MAC PDU. Multiple MAC CEs, such as MAC CE 1 and 2, may be placed together. A MAC subPDU, comprising a MAC CE, may be placed before: a MAC subPDU comprising a MAC SDU, or a MAC subPDU comprising padding. FIG. 18B shows an example of a UL MAC PDU. Multiple MAC CEs, such as MAC CE 1 and 2, may be placed together. In an embodiment, a MAC subPDU comprising a MAC CE may be placed after all MAC subPDUs comprising a MAC SDU. In addition, the MAC subPDU may be placed before a MAC subPDU comprising padding.

[0244] In an example, a MAC entity of a base station may transmit one or more MAC CEs to a MAC entity of a wireless device. FIG. 19 shows an example of multiple LCIDs that may be associated with the one or more MAC CEs. The one or more MAC CEs comprise at least one of: a SP ZP CSI-RS Resource Set Act! vation / Deacti vation MAC CE, a PUCCH spatial relation Activation / Deactivation MAC CE, a SP SRS Activation / Deactivation MAC CE, a SP CSI reporting on PUCCH Activation / Deactivation MAC CE, a TCI State Indication for UE-specific PDCCH MAC CE, a TCI State Indication for UE-specific PDSCH MAC CE, an Aperiodic CSI Trigger State Subselection MAC CE, a SP CSI-RS / CSI-IM Resource Set Activation / Deactivation MAC CE, a wireless device contention resolution identity MAC CE, a timing advance command MAC CE, a DRX command MAC CE, a Long DRX command MAC CE, an SCell activation / deactivation MAC CE (1 Octet), an SCell activation / deactivation MAC CE (4 Octet), and / or a duplication activation / deactivation MAC CE. In an example, a MAC CE, such as a MAC CE transmitted by a MAC entity of a base station to a MAC entity of a wireless device, may have an LCID in the MAC subheader corresponding to the MAC CE. Different MAC CE may have different LCID in the MAC subheader corresponding to the MAC CE. For example, an LCID given by 111011 in a MAC subheader may indicate that a MAC CE associated with the MAC subheader is a long DRX command MAC CE.

[0245] In an example, the MAC entity of the wireless device may transmit to the MAC entity of the base station one or more MAC CEs. FIG. 20 shows an example of the one or more MAC CEs. The one or more MAC CEs may comprise at least one of: a short buffer status report (BSR) MAC CE, a beam failure recovery (BFR) MAC CE, a truncated BFR MAC CE, a truncated enhanced BFR MAC CE, a long BSR MAC CE, a C-RNTI MAC CE, a configured grant confirmation MAC CE, a single entry PHR MAC CE, a multiple entry PHR MAC CE, a short truncated BSR, and / or a long truncated BSR etc. In an example, a MAC CE may have an LCID in the MAC subheader corresponding to the MAC CE. Different MAC CE may have different LCID in the MAC subheader corresponding to the MAC CE. For example, an LCID given by 43 in a MAC subheader may indicate that a MAC CE associated with the MAC subheader is a truncated enhanced BFR MAC CE.

[0246] In carrier aggregation (CA), two or more component carriers (CCs) may be aggregated. A wireless device may simultaneously receive or transmit on one or more CCs, depending on capabilities of the wireless device, using the technique of CA. In an embodiment, a wireless device may support CA for contiguous CCs and / or for non-contiguous CCs. CCs may be organized into cells. For example, CCs may be organized into one primary cell (PCell) and one or more secondary cells (SCells) . When configured with CA, a wireless device may have one RRC connection with a network. During an RRC connection establishment / re-establishment / handover, a cell providing NAS mobility information may be a serving cell. During an RRC connection re-establishment / handover procedure, a cell providing a security input may be a serving cell. In an example, the serving cell may denote a PCell. In an example, a base station may transmit, to a wireless device, one or more messages comprising configuration parameters of a plurality of one or more SCells, depending on capabilities of the wireless device.

[0247] When configured with CA, a base station and / or a wireless device may employ an activation / deactivation mechanism of an SCell to improve battery or power consumption of the wireless device. When a wireless device is configured with one or more SCells, a base station may activate or deactivate at least one of the one or more SCells. Upon configuration of an SCell, the SCell may be deactivated unless an SCell state associated with the SCell is set to “activated” or “dormant".

[0248] A wireless device may activate / d eactivate an SCell in response to receiving an SCell Activation / Deactivation MAC CE (e.g., as shown in FIG. 21 A and / or FIG. 21 B which will be described later in this specification). In an example, a base station may transmit, to a wireless device, one or more messages comprising an SCell timer (e.g., sCellDeactivationTimer). In an example, a wireless device may deactivate an SCell in response to an expiry of the SCell timer.

[0249] When a wireless device receives an SCell Activation / Deactivation MAC CE activating an SCell, the wireless device may activate the SCell. In response to the activating the SCell, the wireless device may perform operations comprising SRS transmissions on the SCell; CQI / PM l / RI / CRI reporting for the SCell; PDCCH monitoring on the SCell; PDCCH monitoring for the SCell; and / or PUCCH transmissions on the SCell. In response to the activating of the SCell, the wireless device may start or restart a first SCell timer (e.g., sCellDeactivationTimer) associated with the SCell. The wireless device may start or restart the first SCell timer in the slot when the SCell Activation / Deactivation MAC CE activating the SCell has been received. In an example, in response to the activating the SCell, the wireless device may (re-)initialize one or more suspended configured uplink grants of a configured grant Type 1 associated with the SCell according to a stored configuration. In an example, in response to activating the SCell, the wireless device may trigger PHR.

[0250] When a wireless device receives an SCell Activation / Deactivation MAC CE deactivating an activated SCell, the wireless device may deactivate the activated SCell. In an example, when a first SCelltimer (e.g . , sCellDeactivationTimer) associated with an activated SCell expires, the wireless device may deactivate the activated SCell. In response to the deactivating the activated SCell, the wireless device may stop the first SCell timer associated with the activated SCell. In an example, in response to the deactivating the activated SCell, the wireless device may clear one or more configured downlink assignments and / or one or more configured uplink grants of a configured uplink grant Type 2 associated with the activated SCell. In an example, in response to the deactivating the activated SCell, the wireless device may: suspend one or more configured uplink grants of a configured uplink grant Type 1 associated with the activated SCell; and / or flush HARQ buffers associated with the activated SCell.

[0251] When an SCell is deactivated, a wireless device may not perform operations comprising: transmitting SRS on the SCell; reporting CQI / PM l / RI / CRI for the SCell; transmitting on UL-SCH on the SCell; transmitting on RACH on the SCell; monitoring at least one first PDCCH on the SCell; monitoring at least one second PDCCH for the SCell; and / or transmitting a PUCCH on the SCell. When at least one first PDCCH on an activated SCell indicates an uplink grant or a downlink assignment, a wireless device may restart a first SCell timer (e.g., sCellDeactivationTimer) associated with the activated SCell. In an example, when at least one second PDCCH on a serving cell (e.g., a PCell or an SCell configured with PUCCH, i.e. , PUCCH SCell) scheduling the activated SCell indicates an uplink grant or a downlink assignment for the activated SCell, a wireless device may restart the first SCell timer (e.g., sCellDeactivationTimer) associated with the activated SCell. In an example, when an SCell is deactivated, if there is an ongoing random access procedure on the SCell, a wireless device may abort the ongoing random access procedure on the SCell.

[0252] FIG. 21 A shows an example of an SCell Activation / Deacti vation MAC CE of one octet. A first MAC PDU subheader with a first LCID (e.g., '111010' as shown in FIG. 19) may identify the SCellAct! vation / Deacti vation MAC CE of one octet. The SCell Act! vation / Deacti vation MAC CE of one octet may have a fixed size. The SCell Activation / Deactivation MAC CE of one octet may comprise a single octet. The single octet may comprise a first number of C-fields (e.g., seven) and a second number of R-fields (e.g., one).

[0253] FIG. 21 B shows an example of an SCell Activation / Deactivation MAC CE of four octets. A second MAC PDU subheader with a second LCID (e.g., ‘111001’ as shown in FIG. 19) may identify the SCell Activation / Deactivation MAC CE of four octets. The SCell Activation / Deactivation MAC CE of four octets may have a fixed size. The SCell Activation / Deactivation MAC CE of four octets may comprise four octets. The four octets may comprise a third number of C-fields (e.g., 31) and a fourth number of R-fields (e.g., 1).

[0254] In FIG. 21A and / or FIG. 21 B, a Ci field may indicate an activation / deactivation status of an SCell with an SCell index i if an SCell with SCell index i is configured. In an example, when the Ci field is set to one, an SCell with an SCell index I may be activated. In an example, when the Ci field is set to zero, an SCell with an SCell index i may be deactivated. In an example, if there is no SCell configured with SCellindex i, the wireless device may ignore the Ci field. In FIG. 21 A and FIG. 21 B, an R field may indicate a reserved bit. The R field may be set to zero.

[0255] A base station may configure a wireless device with uplink (UL) bandwidth parts (BWPs) and downlink (DL) BWPs to enable bandwidth adaptation (BA) on a PCell. If carrier aggregation is configured, the base station may further configure the wireless device with at least DL BWP(s) (i.e., there may be no UL BWPs in the UL) to enable BA on an SCell. For the PCell, an initial active BWP may be a first BWP used for initial access. For the SCell, a first active BWP may be a second BWP configured for the wireless device to operate on the SCell upon the SCell being activated. In paired spectrum (e.g., FDD), a base station and / or a wireless device may independently switch a DL BWP and an UL BWP. In unpaired spectrum (e.g., TDD), a base station and / or a wireless device may simultaneously switch a DL BWP and an UL BWP.

[0256] In an example, a base station and / or a wireless device may switch a BWP between configured BWPs by means of a DCI or a BWP inactivity timer. When the BWP inactivity timer is configured for a serving cell, the base station and / or the wireless device may switch an active BWP to a default BWP in response to an expiry of the BWP inactivity timer associated with the serving cell. The default BWP may be configured by the network. In an example, for FDD systems, when configured with BA, one UL BWP for each uplink carrier and one DL BWP may be active at a time in an active serving cell. In an example, for TDD systems, one DL / UL BWP pair may be active at a time in an active serving cell. Operating on the one UL BWP and the one DL BWP (or the one DL / UL pair) may improve wireless device battery consumption. BWPs other than the one active UL BWP and the one active DL BWP that the wireless device may work on may be deactivated. On deactivated BWPs, the wireless device may: not monitor PDCCH; and / or not transmit on PUCCH, PRACH, and UL-SCH.

[0257] In an example, a serving cell may be configured with at most a first number (e.g., four) of BWPs. In an example, for an activated serving cell, there may be one active BWP at any point in time. In an example, a BWP switching for a serving cell may be used to activate an inactive BWP and deactivate an active BWP at a time. In an example, the BWP switching may be controlled by a PDCCH indicating a downlink assignment or an uplink grant. In an example, the BWP switching may be controlled by a BWP inactivity timer (e.g., bwp-ln activity Timer) In an example, the BWP switching may be controlled by a MAC entity in response to initiating a Random Access procedure. Upon addition of an SpCell or activation of an SCell, one BWP may be initially active without receiving a PDCCH indicating a downlink assignment or an uplink grant. The active BWP for a serving cell may be indicated by RRC and / or PDCCH. In an example, for unpaired spectrum, a DL BWP may be paired with a UL BWP, and BWP switching may be common for both UL and DL.

[0258] FIG. 22 shows an example of BWP switching on a cell (e.g., PCell or SCell). In an example, a wireless device may receive, from a base station, at least one RRC message comprising parameters of a cell and one or more BWPs associated with the cell. The RRC message may comprise: RRC connection reconfiguration message (e.g., RRCReconfiguration); RRC connection reestablishment message (e.g., RRCReestablishment); and / or RRC connection setup message (e.g., RRCSetup). Among the one or more BWPs, at least one BWP may be configured as the first active BWP (e.g., BWP 1), one BWP as the default BWP (e.g., BWP 0). The wireless device may receive a command (e.g., RRC message, MAC CE or DCI) to activate the cell at an nth slot. In case the cell is a PCell, the wireless device may not receive the command activating the cell, for example, the wireless device may activate the PCell once the wireless device receives RRC message comprising configuration parameters of the PCell. The wireless device may start monitoring a PDCCH on BWP 1 in response to activating the cell.

[0259] In an example, the wireless device may start (or restart) a BWP inactivity timer (e.g., bwp- InactivityTimer) at an mthslot in response to receiving a DCI indicating DL assignment on BWP 1 . The wireless device may switch back to the default BWP (e.g., BWP 0) as an active BWP when the BWP inactivity timer expires, at sthslot. The wireless device may deactivate the cell and / or stop the BWP inactivity timer when the sCellDeactivationTimer expires (e.g., if the cell is a SCell). In response to the cell being a PCell, the wireless device may not deactivate the cell and may not apply the sCellDeactivationTimer on the PCell.

[0260] In an example, a MAC entity may apply normal operations on an active BWP for an activated serving cell configured with a BWP comprising: transmitting on UL-SCH; transmitting on RACH; monitoring a PDCCH; transmitting PUCCH; receiving DL-SCH; and / or (re-) initializing any suspended configured uplink grants of configured grant Type 1 according to a stored configuration, if any.

[0261] In an example, on an inactive BWP for each activated serving cell configured with a BWP, a MAC entity may: not transmit on UL-SCH; not transmit on RACH; not monitor a PDCCH; not transmit PUCCH; not transmit SRS, not receive DL-SCH; clear any configured downlink assignment and configured uplink grant of configured grant Type 2; and / or suspend any configured uplink grant of configured Type 1.

[0262] In an example, if a MAC entity receives a PDCCH for a BWP switching of a serving cell while a Random Access procedure associated with this serving cell is not ongoing, a wireless device may perform the BWP switching to a BWP indicated by the PDCCH. In an example, if a bandwidth part indicator field is configured in DCI format 1_1 , the bandwidth part indicator field value may indicate the active DL BWP, from the configured DL BWP set, for DL receptions. In an example, if a bandwidth part indicator field is configured in DCI format 0_1 , the bandwidth part indicator field value may indicate the active UL BWP, from the configured UL BWP set, for UL transmissions.

[0263] In an example, for a primary cell, a wireless device may be provided by a higher layer parameter Default-DL-BWP a default DL BWP among the configured DL BWPs. If a wireless device is not provided a default DL BWP by the higher layer parameter Default-DL-BWP, the default DL BWP is the initial active DL BWP. In an example, a wireless device may be provided by higher layer parameter bwp-lnactivityTimer, a timer value for the primary cell. If configured, the wireless device may increment the timer, if running, every interval of 1 millisecond for frequency range 1 or every 0.5 milliseconds for frequency range 2 if the wireless device may not detect a DCI format 1_1 for paired spectrum operation or if the wireless device may not detect a DCI format 1_1 or DCI format 0_1 for unpaired spectrum operation during the interval.

[0264] In an example, if a wireless device is configured for a secondary cell with higher layer parameter Default-DL-BWP indicating a default DL BWP among the configured DL BWPs and the wireless device is configured with higher layer parameter bwp-lnactivityTimer indicating a timer value, the wireless device procedures on the secondary cell may be same as on the primary cell using the timer value for the secondary cell and the default DL BWP for the secondary cell.

[0265] In an example, if a wireless device is configured by higher layer parameter Active-BWP-DL-SCell a first active DL BWP and by higher layer parameter Active-BWP-UL-SCell a first active UL BWP on a secondary cell or carrier, the wireless device may use the indicated DL BWP and the indicated UL BWP on the secondary cell as the respective first active DL BWP and first active UL BWP on the secondary cell or carrier.

[0266] In an example, a set of PDCCH candidates for a wireless device to monitor is defined in terms of PDCCH search space sets. A search space set comprises a CSS set or a USS set. A wireless device monitors PDCCH candidates in one or more of the following search spaces sets: a TypeO-PDCCH CSS set configured by pdcch-ConfigSIB1 in MIB or by searchSpaceSIBI in PDCCH-ConfigCommon or by searchSpaceZero in PDCCH-ConfigCommon for a DCI format with CRC scrambled by a SI-RNTI on the primary cell of the MCG, a TypeOA-PDCCH CSS set configured by searchSpaceOtherSystemlnformation in PDCCH-ConfigCommon for a DCI format with CRC scrambled by a SI-RNTI on the primary cell of the MCG, a Typel-PDCCH CSS set configured by ra-SearchSpace in PDCCH-ConfigCommon for a DCI format with CRC scrambled by a RA-RNTI, a MsgB-RNTI, or a TC-RNTI on the primary cell, a Type2- PDCCH CSS set configured by pagingSearchSpace in PDCCH-ConfigCommon for a DCI format with CRC scrambled by a P-RNTI on the primary cell of the MCG, a Type3-PDCCH CSS set configured by SearchSpace in PDCCH-Config with searchSpaceType = common for DCI formats with CRC scrambled by INT-RNTI, SFI-RNTI, TPC-PUSCH-RNTI, TPC-PUCCH-RNTI, TPC-SRS-RNTI, CI-RNTI, or PS-RNTI and, only for the primary cell, C-RNTI, MCS-C-RNTI, or CS-RNTI(s), and a USS set configured by SearchSpace in PDCCH-Config with searchSpaceType = ue-Specific for DCI formats with CRC scrambled by C-RNTI, MCS-C-RNTI, SP-CSI-RNTI, CS-RNTI(s), SL-RNTI, SL-CS-RNTI, or SL-L-CS-RNTI.

[0267] In an example, a wireless device determines a PDCCH monitoring occasion on an active DL BWP based on one or more PDCCH configuration parameters (e.g. , based on example embodiment of FIG. 27 which will be described later) comprising: a PDCCH monitoring periodicity, a PDCCH monitoring offset, and a PDCCH monitoring pattern within a slot. For a search space set (SS s), the wireless device determines that a PDCCH monitoring occasion(s) exists in a slot with number nfin a frame with number n^if is a number of slots in a frame when numerology p isconfigured. osis a slot offset indicated in the PDCCH configuration parameters (e.g., based on example embodiment of FIG. 27). ksis a PDCCH monitoring periodicity indicated in the PDCCH configuration parameters (e.g., based on example embodiment of FIG. 27). The wireless device monitors PDCCH candidates for the search space set for Tsconsecutive slots, starting from slotand does not monitor PDCCH candidates for search space set s for the next ks— Tsconsecutive slots. In an example, a USS atCCE aggregation level L e {1, 2, 4, 8, 16} is defined by a set of PDCCH candidates for CCE aggregation level L.

[0268] In an example, a wireless device decides, for a search space set s associated with CORESET p,CCE indexes for aggregation level L corresponding to PDCCH candidate ms nciof the search space set in slot for an active DL BWP of a serving cell corresponding to carrier indicator field value nCIas L ■p mod 3 = 1, Ap= 39839 for p mod 3 = 2, and D = 65537', i = 0, ••• , L — f; / CCE pis the number ofCCEs, numbered from 0 to NCCE p— 1, in CORESET p nCIis the carrier indicator field value if the wireless device is configured with a carrier indicator field by CrossCarrierSchedulingConfig for the serving cell on which PDCCH is monitored; otherwise, including for any CSS, nCI= O,' ms nci= 0, .-is the number of PDCCH candidates the wireless device is configured to monitor for aggregation level L of a search space set s for a serving cell corresponding to nCI', for any CSS, M^ax=over all configured nCIvalues for a CCE aggregation level L of search space set s; and the RNTI value used for nRNT| is the C-RNTI.

[0269] In an example, a wireless device may monitor a set of PDCCH candidates according to configuration parameters of a search space set comprising a plurality of search spaces (SSs). The wireless device may monitor a set of PDCCH candidates in one or more CORESETs for detecting one or more DCIs. A CORESET may be configured based on the example embodiment of FIG. 26 which will be described later. Monitoring may comprise decoding one or more PDCCH candidates of the set of thePDCCH candidates according to the monitored DCI formats. Monitoring may comprise decoding a DCI content of one or more PDCCH candidates with possible (or configured) PDCCH locations, possible (or configured) PDCCH formats (e.g., number of CCEs, number of PDCCH candidates in common SSs, and / or number of PDCCH candidates in the UE-specific SSs) and possible (or configured) DCI formats. The decoding may be referred to as blind decoding. The possible DCI formats may be based on example embodiments of FIG. 23.

[0270] FIG. 23 shows examples of DCI formats which may be used by a base station to transmit control information to a wireless device or used by the wireless device for PDCCH monitoring. Different DCI formats may comprise different DCI fields and / or have different DCI payload sizes. Different DCI formats may have different signaling purposes In an example, DCI format 0_0 may be used to schedule PUSCH in one cell. DCI format 0_1 may be used to schedule one or multiple PUSCH in one cell or indicate CG-DFI (configured grant-Downlink Feedback Information) for configured grant PUSCH, etc. The DCI format(s) which the wireless device may monitor in a SS may be configured.

[0271] FIG. 24A shows an example of configuration parameters of a master information block (MIB) of a cell (e g., PCell). In an example, a wireless device, based on receiving primary synchronization signal (PSS) and / or secondary synchronization signal (SSS), may receive a MIB via a PBCH. The configuration parameters of a MIB may comprise six bits (systemFrameNumber) of system frame number (SFN), subcarrier spacing indication (subCarrierSpacingCommon), a frequency domain offset (ssb- SubcarrierOffset) between SSB and overall resource block grid in number of subcarriers, an indication (cellBarred) indicating whether the cell is bared, a DMRS position indication (dmrs-TypeA-Position) indicating position of DMRS, parameters of CORESET and SS of a PDCCH (pdcch-ConfigSIB1) comprising a common CORESET, a common search space and necessary PDCCH parameters, etc.

[0272] In an example, a pdcch-ConfigSIB1 may comprise a first parameter (e.g., control ResourceSetZero) indicating a common ControlResourceSet (CORESET) with ID #0 (e.g., CORESETSO) of an initial BWP of the cell, control ResourceSetZero may be an integer between 0 and 15. Each integer between 0 and 15 may identify a configuration of CORESET#0.

[0273] FIG. 24B shows an example of a configuration of CORESET#0. As shown in FIG. 24B, based on a value of the integer of controlResourceSetZero, a wireless device may determine a SSB and CORESET#0 multiplexing pattern, a number of RBs for CORESET#0, a number of symbols for CORESET#0, an RB offset for CORESET#0.

[0274] In an example, a pdcch-ConfigSIB1 may comprise a second parameter (e.g., search SpaceZero) indicating a common search space with ID #0 (e.g., SS#0) of the initial BWP of the cell. searchSpaceZero may be an integer between 0 and 15. Each integer between 0 and 15 may identify a configuration of SS#0.

[0275] FIG. 24C shows an example of a configuration of SS#0. As shown in FIG. 24C, based on a value of the integer of searchSpaceZero, a wireless device may determine one or more parameters (e.g., 0, M) for slot determination of PDCCH monitoring, a first symbol index for PDCCH monitoring and / or a number of search spaces per slot.

[0276] In an example, based on receiving a MIB, a wireless device may monitor PDCCH via SS#0 of CORESET#0 for receiving a DCI scheduling a system information block 1 (SIB1 ). A SIB1 message may be implemented based on the example embodiment of FIG. 25. The wireless device may receive the DCI with CRC scrambled with a system information radio network temporary identifier (SI-RNTI) dedicated for receiving the SIB1.

[0277] FIG. 25 shows an example of RRC configuration parameters of system information block (SIB). A SIB (e.g., SIB1) may be transmitted to all wireless devices in a broadcast way. The SIB may contain information relevant when evaluating if a wireless device is allowed to access a cell, information of paging configuration and / or scheduling configuration of other system information. A SIB may contain radio resource configuration information that is common for all wireless devices and barring information applied to a unified access control. In an example, a base station may transmit to a wireless device (or a plurality of wireless devices) one or more SIB information. As shown in FIG. 25, parameters of the one or more SIB information may comprise: one or more parameters (e.g., cellSelectionlnfo) for cell selection related to a serving cell, one or more configuration parameters of a serving cell (e.g., in ServingCellConfigCommonSIB IE), and one or more other parameters. The ServingCellConfigCommonSIB IE may comprise at least one of: common downlink parameters (e.g., in DownlinkConfigCommonSIB IE) of the serving cell, common uplink parameters (e.g., in UplinkConfigCommonSIB IE) of the serving cell, and other parameters.

[0278] In an example, a DownlinkConfigCommonSIB IE may comprise parameters of an initial downlink BWP (initialDownlinkBWP IE) of the serving cell (e.g., SpCell). The parameters of the initial downlink BWP may be comprised in a BWP-DownlinkCommon IE (as shown in FIG. 26). The BWP-DownlinkCommon IE may be used to configure common parameters of a downlink BWP of the serving cell. The base station may configure the locationAndBandwidth so that the initial downlink BWP contains the entire CORESET#0 of this serving cell in the frequency domain. The wireless device may apply the locationAndBandwidth upon reception of this field (e.g , to determine the frequency position of signals described in relation to this locationAndBandwidth) but it keeps CORESET#0 until after reception of RRCSetup / RRCResume / RRCReestablishment.

[0279] In an example, the DownlinkConfigCommonSIB IE may comprise parameters of a paging channel configuration. The parameters may comprise a paging cycle value (T, by defaultPagingCycle IE), a parameter (nAndPaging FrameOffset IE) indicating total number N) of paging frames (PFs) and paging frame offset (PF_offsef) in a paging DRX cycle, a number (Ns) for total paging occasions (POs) per PF, afirst PDCCH monitoring occasion indication parameter {firstPDCCH-MonitoringOccasionofPO IE) indicating a first PDCCH monitoring occasion for paging of each PO of a PF. The wireless device, based on parameters of a PCCH configuration, may monitor PDCCH for receiving paging message.

[0280] In an example, the parameter first-PDCCH-MonitoringOccasionOfPO may be signaled in SIB1 for paging in initial DL BWP. For paging in a DL BWP other than the initial DL BWP, the parameter first- PDCCH-MonitoringOccasionOfPO may be signaled in the corresponding BWP configuration.

[0281] FIG. 26 shows an example of RRC configuration parameters (e.g., BWP-DownlinkCommon IE) in a downlink BWP of a serving cell. A base station may transmit to a wireless device (or a plurality of wireless devices) one or more configuration parameters of a downlink BWP (e.g., initial downlink BWP) of a serving cell.

[0282] As shown in FIG. 26, the one or more configuration parameters of the downlink BWP may comprise: one or more generic BWP parameters of the downlink BWP, one or more cell specific parameters for PDCCH of the downlink BWP (e.g., in pdcch-ConfigCommon IE), one or more cell specific parameters for the PDSCH of this BWP (e.g., in pdsch-ConfigCommon IE), and one or mor other parameters.

[0283] A pdcch-ConfigCommon IE may comprise parameters of COESET #0 (e.g., controlResourceSetZero) which may be used in any common or UE-specific search spaces.

[0284] A value of the controlResourceSetZero may be interpreted like the corresponding bits in MIB pdcch-ConfigSIB1.

[0285] A pdcch-ConfigCommon IE may comprise parameters (e.g., in commonControlResourceSet) of an additional common control resource set which may be configured and used for any common or UE-specific search space. If the network configures this field, it uses a ControlResourceSetld other than 0 for this ControlResourceSet.

[0286] The network configures the commonControlResourceSet in SIB1 so that it is contained in the bandwidth of CORESET#0. A pdcch-ConfigCommon IE may comprise parameters (e.g., in commonSearchSpaceLisf) of a list of additional common search spaces.

[0287] Parameters of a search space may be implemented based on the example of FIG. 27 which will be described later. A pdcch-ConfigCommon IE may indicate, from a list of search spaces, a search space for paging (e.g., pagingSearchSpace), a search space for random access procedure (e.g., ra-Search Space), a search space for SIB1 message (e.g., searchSpaceSIBI), a common search space#0 (e.g., searchSpaceZero), and one or more other search spaces.

[0288] As shown in FIG. 26, a control resource set (CORESET) may be associated with a CORESET index (e g., ControlResourceSetld).

[0289] A CORESET may be implemented based on example embodiments described above with respect to FIG. 14A and / or FIG. 14B.

[0290] The CORESET index with a value of 0 may identify a common CORESET configured in MIB and in ServingCellConfigCommon (controlResourceSetZero) and may not be used in the ControlResourceSet IE.

[0291] The CORESET index with other values may identify CORESETs configured by dedicated signaling or in SIB1. The controlResourceSetld is unique among the BWPs of a serving cell. A CORESET may be associated with coresetPool Index indicating an index of a CORESET pool for the CORESET.

[0292] A CORESET may be associated with a time duration parameter (e.g., duration) indicating contiguous time duration of the CORESET in number of symbols.

[0293] In an example, as shown in FIG. 26, configuration parameters of a CORESET may comprise at least one of: frequency resource indication (e.g., frequencyDomain Resources), a CCE-REG mapping type indicator (e.g., cce-REG-MappingType), a plurality of TCI states, an indicator indicating whether a TCI is present in a DCI, and the like.

[0294] FIG. 27 shows an example of configuration of a search space (e.g., SearchSpace IE).

[0295] In an example, one or more search space configuration parameters of a search space may comprise at least one of: a search space ID (searchSpaceld), a control resource set ID (controlResourceSetld), a monitoring slot periodicity and offset parameter (monltoringSlotPeriodicityAndOffset), a search space time duration value (duration), a monitoring symbol indication (monitoringSymbolsWithinSlot), a number of candidates for an aggregation level (nrofCandidates), and / or a SS type indicating a common SS type or a UE-specific SS type (searchSpaceType) .

[0296] The monitoring slot periodicity and offset parameter may indicate slots (e.g., in a radio frame) and slot offset (e.g., relative to a starting of a radio frame) for PDCCH monitoring.

[0297] The monitoring symbol indication may indicate on which symbol(s) of a slot a wireless device may monitor PDCCH on the SS. The control resource set ID may identify a control resource set on which a SS may be located.

[0298] In an example, a base station may transmit one or more SSBs periodically to a wireless device, or a plurality of wireless devices.

[0299] A wireless device (in RRCJDLE state, RRCJNACTIVE state, or RRC_CONNECTED state) may use the one or more SSBs for time and frequency synchronization with a cell of the base station.

[0300] An SSB, comprising a primary synchronization signal (PSS), a secondary synchronization signal (SSS), a physical broadcast channel (PBCH), and a PBCH DM-RS, may be transmitted based on example embodiments described above with respect to FIG. 11A.

[0301] An SSB may occupy a number (e.g., 4) of OFDM symbols as shown in FIG. 11 A. The base station may transmit one or more SSBs in a SSB burst, e.g., to enable beam-sweeping for PSS / SSS and PBCH.

[0302] An SSB burst comprises a set of SSBs, each SSB potentially transmitted on a different beam. SSBs in the SSB burst may be transmitted in time-division multiplexing fashion.

[0303] In an example, an SSB burst may always be confined to a 5ms window and is either located in first-half or in the second half of a 10ms radio frame. In this specification, an SSB burst may be equivalently referred to as a transmission window (e.g., 5ms) in which the set of SSBs are transmitted.

[0304] In an example, the base station may indicate a transmission periodicity of SSB via RRC message (e.g., ssb-PeriodicityServingCell in ServingCellConfigCommonSIB of SIB1 message, or ServingCellConfigCommon of a serving cell).

[0305] A candidate value of the transmission periodicity may be in a range of {5ms, 10ms, 20ms, 40ms, 80ms, 160ms}. The maximum number of candidate SSBs (Lmax) within an SSB burst depends upon the carrier frequency / band of the cell.

[0306] In an example, Lmax- 4 if fc<— 3GHz, wherein fc is the carrier frequency of the cell. Lmax- 8 if 3GHz<fc<=6GHz. Lmax=64 if fc>=6GHz, etc.

[0307] In an example, a starting OFDM symbol index of a candidate SSB (occupying 4 OFDM symbols) within a SSB burst (5ms) may depend on a subcarrier spacing (SOS) and a carrier frequency band of the cell.

[0308] FIG. 28 shows an example of starting OFDM symbol index determination.

[0309] As shown in FIG. 28, starting OFDM symbol indexes of SSBs in a SSB burst, for a cell configured with 15 kHz and carrier frequency fc<3GHz (Lmax=4), are 2, 8, 16, and 22. OFDM symbols in a half-frame are indexed with the first symbol of the first slot being indexed as 0.

[0310] Starting OFDM symbol indexes of SSBs in a SSB burst, for a cell configured with 15 kHz and carrier frequency 3GHz<fc<6GHz (Lmax=8), are 2, 8, 16, 22, 30, 36, 44 and 50, etc.

[0311] In an example, when the base station is not transmitting the SSBs with beam forming, the base station may transmit only one SSB by using the first SSB starting position.

[0312] FIG. 29 shows an example of SSB transmission of a cell by a base station.

[0313] In the example of FIG. 29, a SOS of the cell is 15 kHz, and the cell is configured with 3GHz<fc<=6GHz.

[0314] Based on the example of FIG. 29, maximum number of candidate SSBs in a SSB burst is 8 (Lmax=8).

[0315] As shown in FIG. 29, SSB#1 starts at symbol#2 of 70 symbols in 5ms, SSB#2 starts at symbol#8, SSB#3 starts at symbol#16, SSB#4 starts at symbol#22, SSB#5 starts at symbol#30, SSB#6 starts at symbol#36, SSB#7 starts at symbol#44, and SSB#8 starts at symbol 50.

[0316] The SSB burst is transmitted in the first half (not the second half as shown in FIG. 29) of a radio frame with 10 ms.

[0317] In an example, the SSB bust (also for each SSB of the SSB burst) may be transmitted in a periodicity.

[0318] In the example of FIG. 29, a default periodicity of a SSB burst is 20 ms, e.g., before a wireless device receives a SIB1 message for initial access of the cell.

[0319] The base station, with 20 ms transmission periodicity of SSB (or SSB burst), may transmit the SSB burst in the first 5 ms of each 20 ms.

[0320] The base station does not transmit the SSB burst in the rest 15 ms of the each 20 ms.

[0321] In an example, a base station may transmit RRC messages (e.g., SIB1 and / or ServingCellConfigCommon IE) indicating cell specific configuration parameters of SSB transmission of a serving cell (e.g., a PCell or a SCell).

[0322] The cell specific configuration parameters may comprise a value for a transmission periodicity (ssb-PeriodicityServingCell) of a SSB burst, locations of a number of SSBs (e.g., active SSBs), of a plurality of candidate SSBs, comprised in the SSB burst. The plurality of candidate SSBs may be implemented based on example embodiments described above with respect to FIG. 28.

[0323] The cell specific configuration parameters may comprise position indication of a SSB in a SSB burst (e.g., ssb-PositionslnBurst). The position indication may comprise a first bitmap (e.g., groupPresence) and a second bitmap (e.g., inOneGroup) indicating locations of a number of SSBs comprised in a SSB burst.

[0324] In an example, a base station may transmit a Master Information Block (MIB) on PBCH, to indicate configuration parameters (for CORESET#0) for a wireless device monitoring PDCCH for receiving a SIB1 message.

[0325] The base station may transmit a MIB message with a transmission periodicity of 80 millisecond (ms). The same MIB message may be repeated (according to SSB periodicity) within the 80 ms. Contents of a MIB message are same over 80 ms period. The same MIB is transmitted over all SSBs within a SS burst.

[0326] In an example, PBCH may indicate that there is no associated SIB1 , in which case a wireless device may be pointed to another frequency from where to search for an SSB that is associated with a SIB1 as well as a frequency range where the wireless device may assume no SSB associated with SIB1 is present. The indicated frequency range may be confined within a contiguous spectrum allocation of the same operator in which SSB is detected.

[0327] In an example, a base station may transmit a SIB1 message with a periodicity of 160 ms. The base station may transmit the same SIB1 message with variable transmission repetition periodicity within 160 ms.

[0328] The default transmission repetition periodicity of SIB1 is 20 ms.

[0329] The base station may determine an actual transmission repetition periodicity based on network implementation.

[0330] In an example, for SSB and CORESET multiplexing pattern 1 , SIB1 repetition transmission period is 20 ms. For SSB and CORESET multiplexing pattern 2 / 3, SIB1 transmission repetition period is the same as the SSB period.

[0331] SIB1 may comprise information regarding the availability and scheduling (e.g , mapping of SIBs to SI message, periodicity, Sl-window size) of other SIBs, an indication whether one or more SIBs are only provided on-demand and in which case, configuration parameters needed by a wireless device to perform an SI request.

[0332] In an example, a base station may transmit SSBs over each serving cell (e.g., a PCell or an SCell) of multiple serving cells configured for a wireless device.

[0333] The base station may transmit SSBs over some serving cells of the multiple serving cells and may not transmit SSBs over other serving cells of the multiple serving cells.

[0334] A serving cell without always-on SSBs may be referred to as an SSB-less serving cell.

[0335] A serving cell with SSBs always transmitted by the base station may be referred to as an always- on-SSB serving cell.

[0336] In addition to always-on SSB and SSB-less, a base station may transmit SSBs over a serving cell based on indication from a wireless device, or from another base station, and / or triggered by the base station itself (e.g., by transmitting a SCell activation / deactivation MAC CE).

[0337] When there is no indication from the wireless device or from another base station or there is no trigger from the base station, the base station may stop transmitting the SSBs. The SSBs transmitted / stopped upon a request may be referred to as on-demand SSBs.

[0338] FIG. 30 shows examples of a variety of SSB transmissions.

[0339] In an example, a base station may configure a serving cell (e.g., a PCell or a SCell, Cell 1 in FIG.30) with always-on SSBs, in which case, the base station keeps transmitting the SSBs with periodicity (e.g., ssb-PeriodicityServingCell) based on configuration parameters of the SSBs.

[0340] The SSBs may be transmitted in a way that a number (e.g., indicated by ssb-PositionsInBurst) of SSBs are comprised in a SSB burst and the SSB burst is transmitted periodically according to the periodicity, e.g , according to example of FIG. 29

[0341] In an example, the always-on SSBs may be mandatorily configured on a PCell, and optionally configured on a SCell. The wireless device may obtain time and / or frequency synchronization (and / or beam alignment) with the serving cell based on the periodically transmitted SSBs. Always transmitting SSBs may increase power consumption of the base station.

[0342] As shown in FIG. 30, a base station may configure a serving cell (e.g., a SCell, Cell 2 in FIG. 30) without SSB transmission, e.g., in order to reduce power consumption of the serving cell. The wireless device may refer to another serving cell (e.g., a PCell or PSCell, or a SCell, Cell 1 in FIG. 30) for obtaining time and / or frequency synchronization with this serving cell.

[0343] The PCell / PSCell / SCell used as the reference (e.g., or a SSB reference cell) of SSBs of this serving cell may be configured by RRC messages (e.g., ServingCellConfigCommon IE, e.g., based on example embodiments of FIG. 33 which will be explained later) of the serving cell.

[0344] The SSB reference cell may be intra-band (in the same frequency band) deployed with this serving cell or may be inter-band (in different frequency bands) deployed with this serving cell.

[0345] The SSB-less configuration for a serving cell may be limited to cases when there is always a SSB reference cell in carrier aggregation (CA) or dual connectivity (DC) deployment and / or when the time / frequency synchronization error between the SSB reference cell and the serving cell is within a threshold, and / or they are deployed in the same frequency range (FR).

[0346] Allowing a serving cell without SSB transmissions may reduce power consumption of the base station.

[0347] As shown in FIG. 30, a base station may configure a serving cell (e.g., a SCell, e.g., Cell 3) with on-demand SSB transmissions, e.g., in order to provide SSBs for time / frequency synchronization and / or parallel ly reduce power consumption of the serving cell especially when there is no SSB reference cell for this serving cell (e.g., due to a single cell deployment, or time / frequency synchronization error between the SSB reference cell and this serving cell being greater than the threshold).

[0348] There are multiple ways of providing the on-demand SSBs for this serving cell.

[0349] As a first way (as shown in FIG. 30) of providing the on-demand SSBs for a serving cell, the base station may trigger to transmit the on-demand SSB based on receiving an uplink wake up signal (WUS) from a wireless device.

[0350] The WUS may be based on existing technologies (e.g., a preamble, an SRS, and / or a SR, etc.), or a new signal designed specifically for the on-demand SSB request. The wireless device may trigger the transmission of the WUS based on traffic loading and / or power level of the wireless device.

[0351] In an example, the wireless device may trigger the transmission of the WUS based on channel measurement of discovery reference signals (DRSs) (if configured) of the serving cell

[0352] In an example, a DRS may be a simplified SSB with only PSS and without SSS or PBCH, a simplified SSB with only SSS and without PSS or PBCH, or a CSI-RS, or a position RS, or a newly defined RS specifically for the on-demand SSB request, or a low-power synchronization signal (LP-SSB) based on on-off-keying (OOK) modulation different from OFDM-based SSBs.

[0353] Before triggering the on-demand SSB for the serving cell, the base station may (optionally) transmit the DRSs for facilitating the wireless device to perform the channel measurement (which may be used by the wireless device to determine whether to trigger the transmission of the WUS).

[0354] When receiving the WUS (e.g., indicating wakeup), the base station may start to transmit the on- demand SSBs. When receiving the WUS (e.g., indicating go-to-sleep) or when not receiving the WUS indicating wakeup on a WUS occasion, the base station may stop (or skip) transmitting the on-demand SSBs.

[0355] Allowing the wireless device to request on-demand SSB transmissions (or request stopping the on- demand transmissions) may enable the base station to stop SSBs transmissions for power / energy saving when there is no wireless device active in this serving cell.

[0356] As a second way (as shown in FIG. 30) of providing the on-demand SSBs for a serving cell, the base station may trigger to transmit the on-demand SSB by transmitting an on-demand SSB trigger.

[0357] In an example, the on-demand SSB trigger may be different from a SCell activation / deactivation MAC CE.

[0358] In an example, the on-demand SSB trigger may be comprised in a SCell activation / deactivation MAC CE indicating both an activation of the SCell and the transmissions of on-demand SSBs via the SCell. The base station may activate the SCell for a wireless device by transmitting a SCell activation / deactivation MAC CE (e.g., based on examples of FIG. 21A and / or FIG. 21 B.).

[0359] Before the on-demand SSBs are triggered, the base station may skip (or may stop / refrain from) transmitting the on-demand SSBs

[0360] After the on-demand SSBs are triggered, the base station may start transmitting the on-demand SSBs.

[0361] In an example, the base station may determine when / whether to activate the SCell (together with the on-demand SSB transmissions) based on traffic load / request of wireless device(s) and / or requests from another base station via backhaul link.

[0362] In an example, the DRSs described above may be optionally transmitted by the base station. The wireless device may transmit channel measurements of the serving cell based on the DRSs to help the base station to decide when / whether to activate the serving cell.

[0363] FIG. 31 shows examples of a variety of SCell activation mechanisms.

[0364] In an example, a wireless device may activate a SCell based on always-on SSBs. The SCell activation with always-on SSBs may be different from a fast SCell activation with tracking reference signal(TRS).

[0365] A TRS may be an aperiodic CSI-RS based on RRC configuration of the SCell.

[0366] As shown in FIG. 31 , when configured with always-on SSBs, the delay (e.g., SCell activation delay) within which the wireless device is required to be able to activate the deactivated SCell depends upon the specified conditions.

[0367] Upon receiving SCell activation command (e.g., SCell Activation MAC CE) in slot n, the wireless device is required to transmit valid CSI report and apply actions related to the activation command for the SCell being activated no later than in slot n +NR slot length

[0368] THARQ (in ms) is the timing between DL data transmission of the MAC CE and acknowledgement transmission corresponding to the reception of the MAC CE.

[0369] Tactivationjime is the SCell activation delay in millisecond with a value determined based on a value of TpirstssB, Trsand TFirstssB.MA and whether the SCell is known or unknown and / or whether the SCell belongs to FR1 or FR2 (e.g , according to 3GPP TS 38.133 clause 8.3.2 SCell Activation delay requirement for deactivated SCell). TpirstssB is the time to the end of the first complete SSB burst indicated by the SMTC, or within 5ms if SMTC is not configured, after slot n +THARQ+ 3ms° NR slot length

[0370] As shown in FIG. 31 , when configured with TRS (e.g., A-TRS, A-CSI-RS), the delay (e.g., SCell activation delay) within which the wireless device is required to activate the deactivated SCell depends upon the specified conditions.

[0371] If the wireless device is allocated A-TRS for fast SCell activation, the wireless device is not required to use the SSB of the target SCell.

[0372] Upon receiving SCell activation command (e.g., SCell Activation MAC CE) in slot n, the wireless device is required to transmit valid CSI report and apply actions related to the activation command for the SCell being activated no later than in slot n +(jn ms)a NR slot lengthv' is the timing between DL data transmission and acknowledgement, Tactivationjime is the SCell activation delay in millisecond with a value determined based on a value of TpirstATRs, Tgapand TATRS and whether the SCell is known or unknown and / or whether the SCell belongs to FR1 or FR2 (e.g., according to 3GPP TS 38.133 clause 8.3.16 Fast SCell Activation delay requirement for deactivated SCell). TpirstATRs is the time to the end of the first comp rlete CSI-RS burst for SCell activation after slot n +T lARQ +3mswhere the CSI-RS burst NR slot length is defined as four CSI-RS resources in two consecutive slots.

[0373] In an example, an SCell in FR1 is (considered by the wireless device) known if it has been meeting the following conditions, otherwise SCell in FR1 is unknown:During the period equal to max(5* measCycleSCell, 5*DRX cycles) for FR1 before the reception of the SCell activation command: the wireless device has sent a valid measurement report for the SCell being activated and the SSB measured remains detectable according to the cell identification conditions. the SSB measured during the period equal to max(5* measCycleSCell, 5*DRX cycles) also remains detectable during the SCell activation delay according to the cell identification conditions.

[0374] measCycleSCell may be configured in RRC measurement configuration parameters of the SCell. The length of a DRX cycle may be configured in RRC messages.

[0375] For the first SCell activation in FR2 bands, the SCell is known if it has been meeting the following conditions, otherwise, the first SCell in FR2 band is unknown:During the period equal to 4s for UE supporting power class 1 / 5 and 3s for a wireless device supporting power class 2 / 3 / 4 before the wireless device receives the last activation command for PDCCH TCI, PDSCH TCI (when applicable) and semi-persistent CSI-RS for CQI reporting (when applicable): the wireless device has sent a valid L3-RSRP measurement report with SSB index, andSCell activation command is received after L3-RSRP reporting and no later than the time when UE receives MAC-CE command for TCI activationDuring the period from L3-RSRP reporting to the valid CQI reporting, the reported SSBs with indexes remain detectable according to the cell identification conditions specified, and the TCI state is selected based on one of the latest reported SSB indexes.

[0376] In the example of FIG. 31 , the SCell activation delay for a SCell configured with always-on SSBs may be longer than the SCell activation delay for a SCell configured with TRS.

[0377] FIG. 32A and FIG. 32B show examples of a SCell activation / deactivation MAC CE for fast SCell activation.

[0378] A base station may transmit to a wireless device a (Enhanced, compared to the SCellAct! vation / Deacti vation MAC CE described above with respect to FIG. 21A) SCell Activation / Deacti vation MAC CE for fast SCell activation.

[0379] In the example of FIG. 32A, the Enhanced SCell Activation / Deactivation MAC CE with one octet Ci field is identified by a MAC subheader with eLCID. It has a variable size and consists of seven C-fields, one R-field and zero or more TRS IDj fields in ascending order based on the SCelllndexfor SCells indicated by the Ci field(s) to be activated. The Enhanced SCell Activation / Deactivation MAC CE of with one octet Ci field is defined as shown in FIG. 32A.

[0380] In the example of FIG. 32B, the Enhanced SCell Activation / Deactivation MAC CE with four octet Ci field is identified by a MAC subheader with eLCID. It has a variable size and consists of 31 C-fields, one R- field and zero or more TRS IDj fields in ascending order based on the SCelllndex for SCells indicated by the Ci field(s) to be activated. The Enhanced SCell Activation / Deactivation MAC CE with four octet Ci field is defined as shown in FIG. 32B.

[0381] In the examples of FIG. 32A and FIG. 32B, for the Ci field, if there is an SCell configured for the MAC entity with SCelllndex , this field indicates the activation / deactivation status of the SCell with SCelllndex i, else the MAC entity shall ignore the Ci field. The Ci field is set to 1 to indicate that the SCell with SCelllndex i shall be activated and that a TRS IDj field is included for the SCell. The Ci field is set to 0 to indicate that the SCell with SCelllndex i shall be deactivated and that no TRS ID field is included for this SCell.

[0382] In the examples of FIG. 32A and FIG. 32B, for the TRS ID, field, if TRS I Dj is set to a non-zero value, it indicates the corresponding TRS addressed by scellActivatlonRS-ld is activated. If TRS IDj is set to zero, it indicates that no TRS is used for the corresponding SCell.

[0383] In the examples of FIG. 32A and FIG. 32B, the R field is a reserved bit, set to 0

[0384] In the examples of FIG. 32A and FIG. 32B, a TRS indicated by TRS ID is one of a plurality of TRSs (each TRS has a TRS ID) configured for the SCell. The base station transmits to the wireless device RRC messages comprising configuration parameters of the plurality of TRSs of the SCell.

[0385] In an example, in response to receiving the Enhanced SCell Activation / Deactivation MAC CE (as described above with respect to FIG. 32A and / or FIG. 32B), the wireless device may activate / deactivate one or more SCells and utilize the TRS (for CSI measurement and / or SCell activation) indicated by the MAC CE.

[0386] FIG. 33 shows an example of SSB configurations for a SCell.

[0387] In an example, a wireless device may receive from a base station one or more RRC messages (e.g ., RRCReconfiguration IE). The one or more RRC messages may comprise configuration parameters (e.g., comprised in CellG roupConfig IE, as shown in FIG. 33) of cell group. The configuration parameters of a cell group may comprise SCell configuration parameters of a plurality of SCells (e.g., sCellToAddModList IE).

[0388] In the example of FIG. 33, the SCell configuration parameters of each SCell may comprise a SCell index (sCelllndex), cell common parameters (comprised in ServingCellConfigComm IE) of the SCell, cell parameters (comprised in ServingCellConfig IE) dedicated for the UE of the SCell, and / or a SSB measurement timing configuration (SMTC) (e.g., smtc) for a L3 beam / cell measurement associated with radio resource management (RRM) procedures.

[0389] In the example of FIG. 33, the cell common parameters of the SCell may comprise downlink common configuration parameters (e.g., comprised in DownlinkConfigCommon IE), SSB burst configuration (ssb-PositionsInBursf) , SSB periodicity (ssb-periodicityServingCell), SSB subcarrier spacingssbSubcarrrierSpacing) and SSB transmission power (ss-PBCH-BlockPower).

[0390] In the example of FIG. 33, the downlink common configuration parameters of the SCell may comprise downlink frequency information (e.g., comprised in FrequencylnfoDL), configuration parameters of initial downlink BWP etc. The downlink frequency information of the SCell may comprise a parameter (absoluteFrequencySSB) indicating the frequency of the SSB to be used for this SCell.

[0391] If the parameter (absoluteFrequencySSB) is absent, the wireless device obtains timing reference from the SpCell or an SCell if applicable as described in TS 38.213, or from the SpCell or an SCell indicated by referenceCell, or from the "default cell" if the referenceCell is absent.

[0392] In the example of FIG. 33, the parameter is an ARFCN (absolute radio frequency channel number) value (ARFCN-ValueNR) specified for NR system. The downlink frequency information of the SCell may comprise a parameter (absoluteFrequencyPointA) indicating the absolute frequency position of the reference resource block (Common RB 0) of the SCell.

[0393] In the example of FIG. 33, the downlink frequency information of the SCell may comprise a parameter (referenceCell) indicating a reference cell, i.e., the cell which provides the timing reference and AGC source for this SCell, if this SCell is an SSB-less SCell. If the reference cell is an SCell or PSCell, it should be an activated SCell or activated PSCell. If this field (referenceCell) is absent, a "default cell" is the reference cell.

[0394] FIG. 34 shows an example of on-demand SSB transmissions for a SCell, e.g., based on and / or in addition to the examples of FIG. 30.

[0395] In an example, on-demand SSB transmissions may be used by a base station for network energy saving (operation / configuration / mode / state) on a SCell. When there are no / less active wireless devices in a SCell, the base station may stop always-on SSB transmissions via the SCell or may not transmit / configure the always-on SSB transmissions.

[0396] In an example, on-demand SSB transmissions may be equivalently referred to as adaptive SSB transmissions with a SSB transmission periodicity adaptation, e.g., when the SCell is in an activated state, where the base station may transmit a command indicating an adaption of the SSB transmission periodicity.

[0397] In this specification, the on-demand SSB trigger may be referred to as an indication of SSB periodicity adaptation when the SCell is in an activated state.

[0398] In an example, when the base station determines to activate the SCell for a wireless device, the base station may trigger on-demand SSB transmissions for the wireless device.

[0399] In an example, when a wireless device determines to trigger the on-demand SSB transmissions for a SCell, the wireless device may transmit uplink signals indicating a trigger of the on-demand SSB transmission on the SCell.

[0400] In the example of FIG. 34, on-demand SSBs may be transmitted on an SCell from time instance A to time instance B. The wireless device may receive, in a slot, from a base station a signaling / command indicating / triggering transmissions of the on-demand SSBs.

[0401] In an example, the time instance A when the on-demand SSBs are transmitted / start to be transmitted via the SCell may be determined as at least one of: a number (T) of slots after the slot where the wireless device receives the signaling / command from the base station to trigger the on-demand SSB transmissions or transmits HARQ-ACK corresponding to the signaling / command; the slot where the base station provides / transmits the signaling / command to trigger the on-demand SSB transmissions; the time when the current scenario (e.g., a first scenario during which the SCell is configured to the wireless device but before the wireless device receives a SCell activation command) transitions to the next scenario (e.g., a second scenario during which the UE has received the SCell activation command); or the first transmission occasion of on-demand SSB burst T slots after the slot where the wireless device receives the signaling / command from the base station to trigger the on-demand SSB transmissions or transmits HARQ- ACK corresponding to the signaling / command.

[0402] In an example, a time duration between the reception of the signaling / command indicating / triggering the transmissions of the on-demand SSBs and the time instance A may be referred to as a time gap of the application of the signaling / command.

[0403] In an example, the time instance B may be determined based on examples of FIG. 36 which will be described later in this specification.

[0404] In the example of FIG. 34, the on-demand SSBs may be transmitted in different cases (e.g., case 1 , case 2), in terms of whether always-on SSBs are transmitted via the SCell

[0405] In the example of FIG. 34, the base station may transmit always-on SSBs (e.g., legacy SSBs) periodically on the SCell regardless of whether the SCell is in an activated state or in a deactivated state if the always-on SSBs are configured on the SCell.

[0406] In the example of FIG. 34, for on-demand SSBs configured with case 1 , the base station does not transmit always-on SSBs via the SCell before the SCell is activated or before the on-demand SSBs are transmitted. The base station transmits the on-demand SSBs (e.g., with periodicity P2) from time instance A to time instance B. After the on-demand SSBs are completed, e.g., at time instance B, the base station may stop the on-demand SSB transmission.

[0407] In the example of FIG. 34, for on-demand SSBs configured with case 2, the base station transmits always-on SSBs (e.g., with periodicity P1) via the SCell regardless of whether the on-demand SSBs aretransmitted or not and / or regardless of whether the SCell is in the activated state or in the deactivated state. The base station transmits the on-demand SSBs (e.g., with periodicity P2) from time instance A to time instance B. After the on-demand SSBs are completed, e.g., at time instance B, the base station may stop the on-demand SSB transmission and continue the always-on SSBs transmissions.

[0408] In the example of FIG. 34, the time instance A on which the on-demand SSBs are transmitted on the SCell may be based on an on-demand SSB triggering / command / signaling.

[0409] In an example, the on-demand SSB triggering / command / signaling may be a RRC message, a MAC CE and / or a DCI.

[0410] In an example, depending on whether the wireless device receives the on-demand SSB triggering / command / signaling before or after the wireless device receives a SCell activation command, there may be two scenarios.

[0411] FIG. 35 shows an example of on-demand SSB transmission scenarios for a SCell, e.g., based on examples of FIG. 34. In the example of FIG. 35, the legacy SSBs are illustrated as a purpose of comparison with the on-demand SSBs.

[0412] In the example of FIG. 35, in a first scenario (Scenario 1) of on-demand SSB triggering, after a SCell is configured (e.g., by RRC messages) and before the SCell is activated, the base station transmits the on-demand SSB triggering / command / signaling indicating transmission of the on-demand SSBs via the SCell before the wireless device receives, and / or the base station transmits, a SCell Activation / deactivation MAC CE (or a SCell activation command) indicating an activation of the SCell. The wireless device, based on the on-demand SSBs (with a transmission periodicity P1 ), may perform downlink synchronization, AGC tuning and / or L3 measurement / report for the SCell.

[0413] In an example, the on-demand SSBs may be transmitted with shorter periodicity than the legacy / always-on SSBs on the SCell. Based on the L3 measurement / report of the SCell, the base station may transmit the SCell activation / deactivation MAC CE indicating the activation of the SCell

[0414] In an example, the wireless device may determine that the SCell is a known cell based on the L3 measurement / report obtained on the on-demand SSBs of the SCell and when the wireless device receives the MAC CE.

[0415] In an example, the wireless device may determine whether a SCell is a known cell or a unknow cell based on examples of FIG. 31 .

[0416] In an example, the wireless device may activate the SCell with a shorter SCell activation delay based on determining that the SCell is a known cell. During the SCell activation delay, the wireless device may continue using the on-demand SSBs for L1 CSI report.

[0417] After the wireless device transmits a valid L1 CSI report, based on the on-demand SSBs, of the SCell to the base station, the wireless device completes the SCell activation after which the SCell is considered, by the wireless device, in the activated state.

[0418] Receiving the on-demand SSB command / trigger and / or the on-demand SSBs, before the SCell activation command is received, may enable the wireless device to reduce SCell activation delay.

[0419] In the example of FIG. 35, in a second scenario (Scenario 2) of on-demand SSB triggering, after a SCell is configured (e.g., by RRC messages), the base station transmits the on-demand SSB triggering / command / signaling, together with a SCell activation command and / or after the SCell activation command, indicating transmission of the on-demand SSBs via the SCell. The wireless device, based on receiving the SCell activation command the on-demand SSB triggering / command / signaling, may perform downlink synchronization, AGC tuning and / or L3 measurement / report based on the on-demand SSBs, for the activation of the SCell.

[0420] In an example, the on-demand SSBs may be transmitted with shorter periodicity than the legacy / always-on SSBs on the SCell. In an example, before receiving the SCell activation command, the wireless device may determine that the SCell is an unknow SCell (e.g., if no always-on SSBs are configured for the SCell). Based on the L3 measurement / report of the SCell, the wireless device may determine that the SCell is a known cell based on the L3 measurement / report obtained on the on-demand SSBs of the SCell.

[0421] In an example, the wireless device may activate the SCell with a longer SCell activation delay compared with scenario 1 . During the SCell activation delay, the wireless device may continue using the on-demand SSBs for L1 CSI report. After the wireless device transmits valid L1 CSI report, based on the on-demand SSBs, of the SCell to the base station, the wireless device completes the SCell activation after which the SCell is in the activated state.

[0422] Receiving the on-demand SSB command / trigger together with the SCell activation command may enable the wireless device to reduce power consumption of L1 / L3 measurement for the SCell.

[0423] In an example, different scenarios (e.g., Scenario 1 and Scenario 2 as shown in FIG. 35) may be applied by the base station for different purposes.

[0424] In an example, the base station may use Scenario 1 for on-demand SSB triggering for a SCell when the base station is able to predict / estimate a time for the SCell activation, e.g., based on traffic pattern of the wireless device, power limitation of the wireless device, moving speed of the wireless device, location of the wireless device, etc.

[0425] In an example, the base station may use Scenario 2 for on-demand SSB triggering for a SCell when the base station is not able to predict / estimate a time for the SCell activation.

[0426] FIG. 36 shows an example of on-demand SSB transmissions for a SCell, e.g., based on examples of FIG. 34 and / or FIG. 35. The base station and / or the wireless device may determine, based on multiple options (e.g., option 1 , option 1 A, option 2, option 3, option 4, etc.), the time duration, of on-demand SSB transmission, between time instance A and time instance B during which the on-demand SSBs are transmitted on a SCell.

[0427] In the example of FIG. 36, in option 1 , the base station, after transmitting the on-demand SSB trigger (e.g., after the time gap as described above with respect to FIG. 34), may start to transmit the on- demand SSBs with a periodicity (P1) from time instance A. The base station may keep transmitting the on- demand SSBs after the on-demand SSB trigger.

[0428] In the example of FIG. 36, in option 1 A, the base station, after transmitting the on-demand SSB trigger (e.g., after the time gap), may transmit the on-demand SSBs with a periodicity (P1) from time instance A to time instance B. The base station and / or the wireless device determine the time instance B based on an indication (e.g., on-demand SSB turn-off indication) from the base station indicating that the on-demand SSBs are stopped on the SCell. The base station may stop the on-demand SSBs from time instance B.

[0429] In the example of FIG. 36, in option 2, the base station, after transmitting the on-demand SSB trigger (e.g., after the time gap), may transmit the on-demand SSBs from time instance A to time instance B. The base station and / or the wireless device determine the time instance B based on a time duration indicated by the on-demand SSB trigger. The base station may stop the on-demand SSBs from time instance B.

[0430] In the example of FIG. 36, in option 3, the base station, after transmitting the on-demand SSB trigger (e.g., after the time gap), may transmit the on-demand SSBs from time instance A to time instance B. The base station and / or the wireless device determine the time instance B based on a total number of transmissions of the on-demand SSBs / SSB bursts indicated by the on-demand SSB trigger. The base station may stop the on-demand SSBs from time instance B.

[0431] In the example of FIG. 36, in option 4, the base station, after transmitting the on-demand SSB trigger (e.g., after the time gap), may transmit the on-demand SSBs from time instance A to time instance B. The base station and / or the wireless device may determine the time instance B based on option 1 A / 2 / 3. The base station may stop the on-demand SSBs from time instance B and transmit second SSBs (e.g., another set of SSBs) with different periodicity, e.g., P2. This case may be referred to as an SSB periodicity adaptation (e.g., from P1 to P2).

[0432] Examples of FIG. 34, FIG. 35 and / or FIG. 36 may be combined for different purposes, e.g., trade- off / balance among network energy saving of the base station, L3 measurement accuracy, SCell activation delay and / or power consumption of the wireless device. In an example, Case 1 of FIG. 34 may becombined with Scenario 1 of FIG. 35 (and / or with option 1A / 2 / 3 of FIG. 36) to reduce both power consumption of the base station and / or the wireless device and / or SCell activation delay. Case 2 of FIG. 34 may be combined with Scenario 2 of FIG. 35 (and / or with option 1A / 2 / 3 of FIG. 36) to improve L3 measurement accuracy of the wireless device and / or reduce power consumption of the wireless device, etc.

[0433] In current 3GPP technical discussions on Rel.19 network energy saving, it is proposed that on- demand SSBs may be used as signal reference for SCell activation / deactivation (comprising synchronization), CSI measurement / report, beam management, RLM / BFR, etc. For network energy saving, the base station may be configured with on-demand SSBs, with or without always-on SSBs. The always-on SSBs and the on-demand SSBs may be implemented based on examples of FIG. 34, FIG. 35 and / or FIG. 36.

[0434] In this specification, when OD-SSBs are configured on a cell, AO-SSBs may be referred to or simplified as SSBs when there is no ambiguity for citing an SSB. The legacy SSBs (configured in FIG. 33) may be referred to as AO-SSBs in this specification.

[0435] FIG. 37 shows an example embodiment of RRC configuration of AO-SSBs and OD-SSBs of a cell.

[0436] In an example, a base station may transmit to a wireless device one or more RRC messages (ServingCellConfigCommon as shown in FIG. 37, and / or ServingCellConfig) comprising configuration parameter of a cell (e.g. , a SCell).

[0437] In an example, the configuration parameters of the cell may comprise first parameters of AO-SSBs of the cell, e.g., based on examples of FIG. 28, FIG. 29 and / or FIG. 33. The first parameters may comprise ssb-PositionlnBurst indicating time domain locations of a number of SSBs in each AO-SSB burst, ssb- periodicityServingCell indicating a transmission periodicity of the AO-SSBs, ssbSubCarrierSpacing indicating a SCS of the AO-SSBs, ss-PBCH-BlockPower indicating a transmission power of the AO-SSBs, etc. The frequency location of the AO-SSBs is indicated by absoluteFrequencySSB which is comprised in FrequencylnfoDL IE in DownlinkConfigCommon IE of ServingCellConfigCommon IE (as shown in FIG. 33) of the cell.

[0438] In an example, when the cell is an SSB-less cell (e.g., when absoluteFrequencySSB is absent in FrequencylnfoDL IE in DownlinkConfigCommon IE of ServingCellConfigCommon IE of the cell), one or more of the first parameters (e.g., ssb-Position In Burst, ssb-periodicityServingCell, ssbSubCarrierSpacing) may be absent in the configuration parameters of the cell of the one or more RRC messages.

[0439] In the example of FIG. 37, the configuration parameters of the cell may comprise an OD-SSB configuration (e.g., ondemandssbConfig, odssbConfig, etc.). The OD-SSB configuration may be configured with parameters separately and / or independently from the first parameters of the AO-SSBs of the cell.

[0440] In an example, the OD-SSB configuration may be associated with second parameters comprising: a parameter (e.g., absoluteFrequencySSB) indicating a frequency location of the OD-SSBs within the cell, a parameter (e.g., ssb-Position In Burst) indicating time domain locations of a number of SSBs in each OD- SSB burst, a parameter (e.g., ssb-periodicityServingCell) indicating a transmission periodicity of the OD- SSBs, a parameter (e.g., ssbSubCarrierSpacing) indicating a SOS of the OD-SSBs, a parameter (e.g., ss- PBCH-BlockPower) indicating a transmission power of the OD-SSBs, a parameter (e.g., ssb-TimeOffset) indicating a time offset between the first OD-SSB transmission occasion and a reference point, etc.

[0441] In an example embodiment, the frequency location of the OD-SSBs and the frequency location of the AO-SSBs may be configured in the same BWP (e.g., the configured initial downlink BWP, the configured first active downlink BWP) of the cell.

[0442] In an example embodiment, the frequency location of the OD-SSBs and the frequency location of the AO-SSBs may be configured in different frequency resources in the same BWP of the cell.

[0443] In 3GPP Rel .19 network energy saving technologies, in addition to the OD-SSB transmission described in FIG. 37, another SSB power saving technology may comprise SSB time-domain adaptation for a cell.

[0444] FIG. 38 shows an example of SSB time-domain adaptation for a cell. In the example of FIG. 38, a base station transmits to a wireless device one or more SSBs with a first periodicity (e.g., P1 ) .

[0445] In an example, the first periodicity may be configured to a large value (e.g., 160ms), for RRM / RLM purpose when the wireless device is communicating with the base station on the cell.

[0446] In an example, when the data traffic is increased on the cell for the wireless device, the base station may reduce SSB periodicity from P1 to P2, where P2 may be smaller than P1 . P2 being smaller than P1 may allow the wireless device to obtain more SSBs in a time duration for beam / channel measurement / synchronization. The base station may transmit a first (1st) SSB time-domain adaptation indication for the purpose.

[0447] Based on receiving the first SSB time-domain adaptation indication, the wireless device determines that the SSBs are transmitted by the base station with P2. The wireless device may apply P2 for receiving the SSBs.

[0448] In an example, when the data traffic is reduced on the cell for the wireless device, the base station may increase / relax SSB periodicity from P2 to P1. The base station may transmit a second (1st) SSB timedomain adaptation indication for the purpose. Based on receiving the second SSB time-domain adaptation indication, the wireless device determines that the SSBs are transmitted by the base station with P1 . The wireless device may apply P1 for receiving the SSBs.

[0449] In an example, the SSB time-domain adaptation indication may comprise a DCI. The DCI may be a group common DCI.

[0450] In an example, the SSB time-domain adaptation indication may be applied to a PCell , and / or a SCell.

[0451] In an example, the SSB time-domain adaptation indication may be applied to CD-SSBs and / or NCD-SSBs.

[0452] In an example, for adaptation of SSB in time-domain, the base station may adapt SSB burst periodicity using one or more SSB burst periodicity values, and / or based on two SSB configurations (where up to two configurations can be active).

[0453] In an example, the multiple SSB burst periodicity values and / or the two SSB configurations may be implemented based on examples of FIG. 39A and / or FIG. 39B which will be described later in this specification

[0454] In an example, the two SSB configurations may be configured with two different SSB burst periodicity values. The two SSB configurations may comprise a sparse CD-SSB and an adaptable SSB that is not CD-SSB. The base station may adapt the SSB in the time domain based on the two SSB configurations.

[0455] In an example, two SSB configurations with different periodicities may be configured. One SSB configuration can be a default configuration, which is used most likely also for legacy UE. While an additional SSB configuration can be added for R19 NES UE. When it comes to adaptation, one way is to only activate / deactivate the additional SSB configuration, i.e., keeping the default SSB periodicity unchanged. Thus, for the legacy UE, they may detect only the default SSB periodicity, and the R19 NES UE can detect both periodicities. A group-common DCI may be used for the activation / deactivation of the additional SSB configuration.

[0456] In an example, a use case scenario where the network may use a second SSB configuration on top of a first one, e.g., to enable faster UE measurement, is the activation of an SCell. In this scenario, the second SSB configuration can be configured as on-demand SSB(s) transmitted on top of the long- periodicity-one, resulting in denser or more frequent SSBs when needed, e.g., with N additional SSB transmissions starting from a specific time instance. L1 / L2 signaling can be used to trigger the second SSB configuration.

[0457] FIG. 39A shows an example RRC message of two SSB periodicity values for SSB periodicity adaptation.

[0458] In the example of FIG. 39A, a ServingCellConfigCommon IE may comprise parameters of SSBs of a cell. The parameters may comprise ssb-PositionlnBurst, ssb-periodicityServingCell, ssbSubcarrierSpacing, ss-PBCH-BlockPower, etc. The frequency location of the SSBs may be indicated by absoluteFrequencySSB configured in FrequencylnfoDL as shown in FIG 33.

[0459] In the example of FIG. 39A, the parameters may further comprise additional-ssb-periodicity indicating an additional periodicity value for SSB periodicity adaptation. The value of additional-ssb- periodicity may be shorter / smaller than the value of ssb-periodidtyServingCell.

[0460] In an example, the base station may transmit the SSBs with a transmission periodicity by using the value of ssb-periodicityServingCeil before the SSB time-domain adaptation is enabled / activated / indicated by an SSB time-domain adaptation indication (e.g., a DCI) as shown in FIG. 38. After the SSB time-domain adaptation is enabled / activated / indicated by the SSB time-domain adaptation indication, the base station may transmit the SSBs with a transmission periodicity by using the value of additional-ssb-periodicity.When the base station transmits the SSBs with the transmission periodicity by using the value of additional- ssb-periodicity, the base station reuses other parameters of the SSBs, e.g., ssb-PositionlnBurst, ssbSubcarrierSpacing, ss-PBCH-BlockPower, etc. In this case, the SSB time-domain adaptation is implemented based on switching between two SSB periodicity values.

[0461] In an example, the base station may transmit the SSBs in the same frequency location (indicated by absoluteFrequencySSB) before the SSB time-domain adaptation and after the SSB time-domain adaptation.

[0462] FIG. 39B shows an example RRC message of two SSB configurations for SSB periodicity adaptation.

[0463] In the example of FIG. 39B, a ServingCellConfigCommon IE may comprise two SSB configurations. Existing RRC parameters in the ServingCellConfigCommon IE, e.g., ssb-PositionlnBurst, ssb-periodicityServingCeil, ssbSubcarrierSpacing, ss-PBCH-BlockPower, etc., may be referred to as configuration parameters of a first SSB configuration in this specification. The frequency location of the first SSB configuration may be indicated by absoluteFrequencySSB configured in Frequency I nfoDL as shown in FIG. 33.

[0464] In the example of FIG. 39B, a second SSB configuration of the two SSB configurations comprised in ServingCellConfigCommon IE of a cell may be configured as AdaptiveSSB-Config IE. Parameters of AdaptiveSSB-Config IE may comprise absoluteFrequencySSB, ssb-PositionlnBurst, ssbSubcarrierSpacing, ss-PBCH-BlockPower, ssb-periodicityServingCeil.

[0465] In an example, the parameters of AdaptiveSSB-Config IE may be separately and / or independently configured from the parameters of the first SSB configuration.

[0466] In an example, one or more parameters of AdaptiveSSB-Config IE may be same as the corresponding parameters of the first SSB configuration. In an example, ssb-PositionlnBurst of AdaptiveSSB-Config IE may be same as the ssb-PositionlnBurst of the first SSB configuration. In an example, ssbSubcarrierSpacing of AdaptiveSSB-Config IE may be same as the ssbSubcarrierSpacing ofthe first SSB configuration. In an example, ss-PBCH-BlockPower of AdaptiveSSB-Config IE may be same as the ss-PBCH-BlockPower of the first SSB configuration, etc.

[0467] In an example, the value of ssb-periodicityServingCell of the second SSB configuration may be shorter / smaller the value of ssb-periodicityServingCell of the first SSB configuration.

[0468] In an example, absoluteFrequencySSB of the second SSB configuration may be different from absoluteFrequencySSB of the first SSB configuration. When absoluteFrequencySSB of the second SSB configuration is absent in the AdaptiveSSB-Config IE, the SSBs are transmitted according to the second SSB configuration and in the frequency location (indicated by absoluteFrequencySSB of the first SSB configuration) when the SSB periodicity adaptation is enabled / activated / indicated.

[0469] In an example, when the SSBs are not configured as CD-SSBs, the absoluteFrequencySSB of the second SSB configuration may be present in the AdaptiveSSB-Config IE. When the SSBs are configured as CD-SSBs, the absoluteFrequencySSB of the second SSB configuration may be absent in the AdaptiveSSB-Config IE.

[0470] In an example, the base station may transmit the SSBs according to the parameters of the first SSB configuration before the SSB time-domain adaptation is enabled / activated / indicated by an SSB timedomain adaptation indication (e.g., a DCI) as shown in FIG. 38. After the SSB time-domain adaptation is enabled / activated / indicated by the SSB time-domain adaptation indication, the base station may transmit the SSBs according to the parameters of the second SSB configuration. In this case, the SSB time-domain adaptation is implemented based on switching between two SSB configurations.

[0471] / / Issue 1 : how to indicate the SSB periodicity adaptation indication for multiple cells?

[0472] In existing technologies (as shown in FIG. 38, FIG. 39A and / or FIG. 39B), SSB time-domain (or periodicity) adaptation (indicated by DCI) is used to change SSB periodicity value, or switch between two SSB configurations. When configured with two SSB configurations, the base station may transmit SSBs with a first SSB configuration, in addition, the base station may use a MAC CE / DCI to trigger, activate and / or deactivate the additional SSB configuration. It is disclosed that the SSB periodicity adaptation may be based on a MAC CE or a DCI (or a group common DCI).

[0473] However, based on existing technologies, it is unclear for a base station and / or a wireless device (or from viewpoint of the base station and / or the wireless device) how to indicate / apply the SSB periodicity adaptation for one or more cells.

[0474] FIG. 40 shows example issues of the existing technologies for indicating / applying the SSB periodicity adaptation for one or more cells.

[0475] In the example of FIG. 40, a base station transmits to a wireless device a SCell activation command, at T1 , indicating an activation of a SCell The SCell may be configured with AO-SSBs with a transmission periodicity P1 , e.g., based on examples of FIG. 34 (for Case 2) and / or FIG. 37.

[0476] In the example of FIG. 40, the base station transmits an SSB time-domain adaptation indication indicating a SSB periodicity adaptation (from P1 to P2) for the SCell, e.g based on examples of FIG. 38, FIG. 39A and / or FIG. 39B. The SSB time-domain adaptation indication may be comprised in a DCI (e.g., a unicast DCI or a group common DCI).

[0477] In an example, the wireless device may be configured with multiple cells (e.g., PCell, PSCell, SCells), it is unclear, based on existing technologies, how to indicate SSB periodicity adaptations for the multiple cells. The base station, based on existing technologies, may transmit multiple DCIs to the wireless device, each DCI corresponding to a respective cell of the multiple cells and indicating the SSB periodicity adaptation for the respective cell. The multiple DCIs may be per wireless device transmitted. Existing technologies may increase signaling overhead for the SSB periodicity adaptation for a plurality of cells and / or for multiple wireless devices.

[0478] One or more example embodiments comprise receiving, by a wireless device from a base station, one or more RRC messages comprising configuration parameters of a DCI with a DCI format. The DCI format may comprise a plurality of SSB periodicity (or time-domain) adaptation indications for the wireless device. The configuration parameters indicate that each SSB periodicity indication, of the plurality of SSB periodicity (or time-domain) adaptation indications in the DCI format, is associated with a respective cell of a plurality of cells configured for the wireless device. Each SSB periodicity indication indicates an SSB periodicity adaptation for a corresponding cell of the plurality of cells.

[0479] In an example, the plurality of SSB periodicity adaptation indications of the wireless device may be comprised in an indication block of the DCI format, wherein the DCI format comprises a plurality of indication blocks for a plurality of wireless devices. Each indication block of the plurality of indication blocks is associated with (or corresponds to) a specific wireless device of a plurality of wireless devices. The one or mor RRC messages may indicate a position indication indicating a starting position of the indication block associated with the wireless device. Different wireless devices may be associated with (or may be configured with) different position indications for the indication blocks of the DCI format for the SSB periodicity adaptation indications for multiple cells. When receiving the DCI format, the wireless device may apply the SSB periodicity adaptation indications (for the plurality of cells configured for the wireless device) comprised in the indication block, of the indication blocks of the DCI format. The position (e.g., the starting position) of the indication block, associated with the wireless device and within the indication blocks of the DCI format, may be determined based on the position indication associated with the wireless device.

[0480] According to an example embodiment, a size of an indication block is determined, by the base station and / or the wireless device, based on a total number of serving cells (e.g., in MCG or in SCG) comprising a PCell and / or one or more SCells configured for the wireless device. In an example, when 7 SCells are configured with a PCell for a wireless device, the size of the indication block for the wirelessdevice may be 8 bits. In an example, when 31 SCells are configured with a PCell for a wireless device, the size of the indication block for the wireless device may be 32 bits.

[0481] In an example embodiment, the plurality of cells may comprise the PCell and SCells of a MCG, or the PSCell and SCells of a SCG, etc., configured for the wireless device. The MCG and the SCG may be associated with different DCIs, wherein a first DCI is used to indicate SSB periodicity adaptation for the cells of the MCG and a second DCI is used to indicate SSB periodicity adaptation for the cells of the SCG. An MCG and a SCG may be implemented based on the examples described above with respect to FIG. 3.

[0482] In an example embodiment, the wireless device receives the DCI with the DCI format comprising the plurality of SSB periodicity adaptation indications.

[0483] In an example embodiment, the plurality of SSB periodicity adaptation indications may be comprised in an indication block of indication blocks of the DCI format, wherein each indication block is associated with a respective wireless device of multiple wireless devices.

[0484] In an example embodiment, when receiving the DCI format, the wireless device may apply the SSB periodicity adaptation indications (for the plurality of cells configured for the wireless device) comprised in an indication block, of indication blocks of the DCI format. The position (e.g., the starting position) of the indication block, associated with the wireless device and within the indication blocks of the DCI format, may be determined based on the position indication associated with the wireless device.

[0485] In an example embodiment, the wireless device applies a first SSB periodicity adaptation indication, of the plurality of SSB periodicity adaptation indications, for a first cell of the plurality of cells, based on: the first SSB periodicity adaptation indication being associated with the first cell and the first SSB periodicity adaptation indication indicating an SSB periodicity change / adaptation. The applying the first SSB periodicity adaptation indication for the first cell may comprise switching to a second SSB periodicity value of the first cell, or switching to a second SSB configuration of the first cell based on examples of FIG. 39A and / or FIG. 39B.

[0486] In an example, the wireless device applies a second SSB periodicity adaptation indication, of the plurality of SSB periodicity adaptation indications, for a second cell of the plurality of cells configured for the wireless device, based on: the second SSB periodicity adaptation indication being associated with the second cell and the second SSB periodicity adaptation indication indicating an SSB periodicity change / adaptation. The applying the second SSB periodicity adaptation indication for the second cell may comprise switching to a second SSB periodicity value of the second cell, or switching to a second SSB configuration of the second cell based on examples of FIG. 39A and / or FIG. 39B.

[0487] In an example, the wireless device does not apply SSB periodicity adaptation for a third cell of the plurality of cells configured for the wireless device, based on: the third SSB periodicity adaptation indication being associated with the third cell and the third SSB periodicity adaptation indication not indicating an SSBperiodicity change / adaptation The not applying the SSB periodicity adaptation indication for the third cell may comprise maintaining the SSB periodicity value unchanged or maintaining the SSB configuration unchanged for the third cell.

[0488] According to an example embodiment, the plurality of SSB periodicity adaptation indications are present in the DCI format (or in an indication block of indication blocks of the DCI format) according to an ascending order of cell indexes of the plurality of cells configured for the wireless device. In this case, the right-most indication of the DCI format corresponds to a first cell (e.g., PCell or a SCell with the lowest SCell index) with the lowest cell index, the second right-most indication corresponds to a second cell with the second lowest cell index, etc.

[0489] According to an example embodiment, the plurality of SSB periodicity adaptation indications are present in the DCI format (or in an indication block of indication blocks of the DCI format) according to a descending order of cell indexes of the plurality of cells. In this case, the right-most indication of the DCI format corresponds to a first cell with the highest cell index, the second right-most indication corresponds to a second cell with the second highest cell index, etc.

[0490] Based on example embodiments, predefining the associations between the plurality of SSB periodicity adaptation indications and the plurality of cells for a wireless device, according to the ascending / descending order of cell indexes of the plurality of cells, may reduce signaling overhead for the configuration of the associations.

[0491] According to an example embodiment, the one or more RRC messages comprises a plurality of location indications for SSB periodicity adaptation indications of the plurality of cells, wherein each location (or position) indication indicates, a location (or position) of a SSB periodicity adaptation indication, of the plurality of SSB periodicity adaptation indications in the DCI format (or in an indication block of indication blocks of the DCI format), for a cell associated with the location indication.

[0492] Based on example embodiments, configuring the associations between the plurality of SSB periodicity adaptation indications and the plurality of cells, by the one or more RRC messages, may enable the base station to flexibly indicate the associations between the plurality of SSB periodicity adaptation indications and the plurality of cells for different wireless devices, so that the base station can use a single group common DCI to indicate SSB periodicity adaptation for multiple cells of multiple wireless devices, where different wireless devices may be configured with different cells.

[0493] According to an example embodiment, a size of a first SSB periodicity adaptation indication for a first cell is determined, by the base station and / or the wireless device, as: a non-zero value based on the first cell being configured with SSB periodicity adaptation; and a zero value (in which case, the indication is absent in the DCI) based on the first cell not being configured with the SSB periodicity adaptation.

[0494] Example embodiments may reduce signaling overhead for SSB periodicity adaptation indications for multiple cells, therefore reducing power consumption of the base station and / or the wireless device.

[0495] In the example of FIG. 40, the base station may transmit the SSB time-domain adaptation indication at T2. Based on existing technologies, it is unclear (from the wireless device point of view) when the SSBs are changed to the adapted periodicity by the base station if the wireless device receives the group common DCI indicating the SSB time-domain adaptation for a cell. Switching between two SSB configurations or adapting SSB periodicity may require some processing time at the base station and / or the wireless device. The wireless device may have no knowledge of the length of a time gap between T2 and T3 where the first SSB transmission occasion with the adapted periodicity (e.g., P2) is available. The base station and the wireless device, by implementing existing technologies, may misalign the adaptation timing for the SSBs, which may result in communication / link broken between the base station and the wireless device.

[0496] One or more example embodiments comprise receiving, by a wireless device from a base station, at a first time interval (e.g., a slot / symbol / subframe), a DCI comprising an SSB periodicity (or time-domain) adaptation indication for a cell. The wireless device determines a time gap between the last symbol of the first time interval and a first symbol of a periodicity-adapted SSB transmission occasion based on at least one of: the wireless device’s capability for applying SSB periodicity adaptation; and / or indication from the base station. The wireless device and / or the base station determines the time gap is shorter than the application time / gap for OD-SSB trigger. The wireless device and / or the base station determines that the adapted SSBs are available no earlier than the time gap after the last symbol of the first time interval. The wireless device starts to receive the periodicity-adapted SSBs no earlier than the time gap after the last symbol of the first time interval. The wireless device and / or the base station determines that the SSBs are transmitted with the orig in al / defau It SSB periodicity (or without the adaptation) before the end of the time gap after the last symbol of the first time interval. The wireless device starts to receive the periodicity- ad apted / changed SSBs after (or no earlier than) the time gap starting from the last symbol of the first time interval.

[0497] According to an example embodiment, the time gap may be preconfigured and / or predefined as a fixed value.

[0498] In an example embodiment, the fixed value may be same as the application time for applying a cell discontinuous transmission (DTX) activation / deactivation command (e.g., DCI format 2_9).

[0499] In an example, when a wireless device receives in slot m on the active DL BWP of a first serving cell a PDCCH providing DCI format 2_9 that indicates a change in activation or deactivation of a current cell DTX operation or cell DRX operation for a second serving cell, the wireless device operates on the second serving cell according to the indicated cell DTX operation or cell DRX operation starting from a sloton the active DL BWP or on the active UL BWP of the second serving cell, respectively, that is not before the beginning of the slot m + d on the active DL BWP of the first serving cell where d is a number of slots for the SCS of the active DL BWP of the first serving cell. The value of d may be predefined / p recon figured based on SCS, e.g . , according to Table 11 .5-1 of 3GPP TS 38.213.

[0500] In an example embodiment, the fixed value may be different from the application time for applying a cell discontinuous transmission (DTX) activation / deactivation command (e.g., DCI format 2_9).

[0501] According to an example embodiment, the time gap is in unit of slots, according to the SCS of the reference cell. The reference cell may be a cell on which the DCI is received, or the SCell for which the SSB periodicity adaptation indication is applied. In an example, the SCS may be determined as the lowest SCS among the cell (or an active BWP of the cell) on which the DCI is received, the SCell (or an active BWP of the SCell) for which the SSB periodicity adaptation indication is applied.

[0502] According to an example embodiment, the wireless device transmits the wireless device capability information comprising one or more parameters indicating the (minimum) time gap for application of the SSB periodicity adaptation indication for a SCell (in an activated state) The (minimum) time gap for application of the SSB periodicity adaptation indication for a SCell (in an activated state) may be separately indicated from a time gap for application of the OD-SSB trigger for a SCell (in a deactivated state) comprised in the one or more parameters. The time gap for application of the SSB periodicity adaptation indication may be shorter than the time gap for application of the OD-SSB trigger. The one or more parameters may be per frequency band indicated. The wireless device transmits wireless device capability information in response to receiving from the base station one or more RRC messages comprising a request of the wireless device capability information.

[0503] According to an example embodiment, the wireless device transmits the wireless device capability information comprising one or more parameters indicating whether SSB periodicity adaptation indication is applied to AO-SSBs and / or OD-SSBs of a SCell. The one or more parameters may indicate at least one of: whether the SSB periodicity adaptation indication is applied to AO-SSBs, whether the SSB periodicity adaptation indication is applied to OD-SSBs, and / or whether the SSB periodicity adaptation indication is applied to both the AO-SSBs and the OD-SSBs of the SCell. The one or more parameters may be per frequency band indicated The wireless device transmits wireless device capability information in response to receiving from the base station one or more RRC messages comprising a request of the wireless device capability information.

[0504] Example embodiments may align the base station and the wireless device regarding the timing for the application of SSB periodicity adaptation indication for a cell, therefore reducing power consumption of the base station and / or the wireless device.

[0505] In the example of FIG. 40, the base station transmits the SSBs for the SCell with the adapted SSB periodicity (P2), after transmitting the SSB periodicity adaptation indication. The base station and / or the wireless device may deactivate the SCell, at T4, e.g., where T4 may occur when the SSBs are periodically transmitted with P2 for the SCell. In existing technologies, it is unclear how to perform SSB time-domain adaptation for a SCell in a deactivated state (e.g., after T4). The base station and the wireless device, by implementing existing technologies, may misalign the transmission (time-domain) pattern for the SSBs, which may result in increased power consumption of the wireless device and / or the base station.

[0506] One or more example embodiments comprise receiving, by a wireless device from a base station, one or more RRC messages comprising configuration parameters of SSBs of a SCell, wherein the configuration parameters indicate a first periodicity and a second periodicity. The wireless device receives, via the SCell, the SSBs with the first periodicity. The wireless device receives a command (e.g., a group common DCI) indicating an SSB periodicity adaptation for the SCell. Based on the SCell being in an activated state and / or based on receiving the command, the wireless device applies the SSB periodicity adaptation for the SCell, wherein the applying the SSB periodicity adaptation comprises receiving, via the SCell, the SSBs with the second periodicity.

[0507] In an example, the wireless device may ignore the SSB periodicity adaptation indication for the SCell based on receiving the SSB periodicity adaptation indication when the SCell is in the deactivated state. The wireless device, when receiving the SSBs with the second periodicity on the SCell (e.g., in the activated state), determines to deactivate the SCell based on receiving a SCell deactivation command or based on an expiry of an SCell deactivation timer. The wireless device receives, via the SCell, the SSBs with the first periodicity, based on the deactivating the SCell and / or determining that the SSB periodicity adaptation is not applicable for the SCell in the deactivated state.

[0508] Example embodiments may align the base station and the wireless device regarding the application (or the applicability) of SSB periodicity adaptation indication for a SCell in different SCell states (e.g., activated state or deactivated state), therefore reducing power consumption of the base station and / or the wireless device.

[0509] FIG. 41 illustrates an example as per an aspect of an embodiment of the present disclosure.

[0510] In the example of FIG. 41 , a base station transmits to a wireless device RRC messages, e.g., at TO. The RRC messages may comprise configuration parameters of one or more cells (e.g., serving cells, PCell, SCells, etc.) (or a plurality of cells).

[0511] In an example, the configuration parameters of a cell (e.g., a PCell, a SCell, or a non-serving cell) may indicate that the SCell is configured with SSB time-domain (periodicity) adaptation.

[0512] In an example, when the SCell is configured with an additional SSB periodicity value on top of a first SSB periodicity value (e.g., based on examples of FIG. 39A), or is configured with two SSBconfigurations (e.g., based on examples of FIG. 39B) , the wireless device may determine that the SCell is configured with SSB time-domain adaptation.

[0513] In an example, when the SCell is not configured with an additional SSB periodicity value on top of a first SSB periodicity value (e.g., based on examples of FIG. 39A), or is not configured with two SSB configurations (e.g., based on examples of FIG. 39B), the wireless device may determine that the SCell is not configured with SSB time-domain adaptation.

[0514] In the example of FIG. 41 , the cell is a SCell.

[0515] In an example, SSB time-domain adaptation may comprise SSB periodicity adaptation between two periodicity values (e.g., based on examples of FIG. 39A) or between two SSB configurations (e.g., based on examples of FIG. 39B).

[0516] In an example, the configuration parameters of the cell may indicate two or more SSB periodicity values, or indicate two SSB configurations, wherein each SSB configuration is associated with one or more SSB parameters as shown in FIG. 33. The two SSB periodicity values and / or the two SSB configurations may be implemented based on examples of FIG. 39A and / or FIG. 39B.

[0517] In an example embodiment, the RRC messages comprise configuration parameters of a DCI (e.g., a group common DCI addressed to a group of wireless devices, or a unicast DCI addressed specifically to the wireless device) with a DCI format comprising a plurality of SSB periodicity (or time-domain) adaptation indications.

[0518] In an example, the group common DCI may be an existing group common DCI format (e.g., DCI format 2_6 , DCI format 2_7, DCI format 2_9), or a new group common DCI format different from the existing group common DCI formats.

[0519] In an example, the group common DCI may be based on the existing DCI format 2_9 by adding one field (e.g., one bit) in a block associated with a serving cell of the wireless device. The field may be placed after the existing Cell DTX / DRX indication and the existing NES-mode indication in the block associated with the serving cell of the wireless device. Each serving cell of the wireless device is associated with a respective block of a plurality of blocks in the DCI format 2_9. Each block of the plurality of blocks in the DCI format 2_9 comprises the field indicating an SSB periodicity (time-domain) adaptation for the serving cell.

[0520] In an example, the field being set to a first value (e.g., 1) may indicate an SSB periodicity (timedomain) adaptation (or may indicate an activation / enabling / triggering / starting of the SSB periodicity adaptation) for the serving cell of the wireless device. The field being set to a second value (e.g., 0) may not indicate an SSB periodicity (time-domain) adaptation (or may indicate a deactivation / disabling / stopping of the SSB periodicity adaptation) for the serving cell of the wireless device.

[0521] In an example embodiment, the configuration parameters indicate that each SSB periodicity indication, of the plurality of SSB periodicity adaptation indications in the DCI format, is associated with a respective cell of the one or more cells. Each SSB periodicity indication indicates an SSB periodicity adaptation for a corresponding cell of the one or more cells.

[0522] In the example of FIG. 41 , the base station transmits to the wireless device, at T1 , a SCell activation command indicating an activation of the SCell. The SCell activation command may be a SCell activation / deactivation MAC CE indicating an activation of the SCell, e.g., based on examples of FIG. 21A, FIG. 21 B, FIG. 31 , FIG. 32A and / or FIG. 32B.

[0523] In the example of FIG. 41 , the wireless device may receive the SSBs of the SCell with the first periodicity (P1 ), e.g., for SCell activation, synchronization, cell / beam measurement, etc.

[0524] In an example, the wireless device may receive the SSBs of the SCell with the first periodicity, before the SCell is activated (e.g., at T1) and after the SCell is configured and the SSBs are configured on the SCell.

[0525] In an example, the wireless device may receive the SSBs of the SCell with the first periodicity (P1) after the SCell is activated (e.g., T1).

[0526] In the examples of FIG. 41 , the wireless device receives, at T2, a DCI indicating SSB periodicity adaptation for the SCell.

[0527] In an example, the DCI may indicate an activation of SSB periodicity adaptation (from P1 to P2) by setting a bit field associated with the SSB periodicity adaptation to a first value (e.g., 1).

[0528] In an example, the wireless device, if the DCI indicating an activation of the SSB periodicity adaptation by setting the bit field to the first value (e.g., 1), may switch the periodicity of the SSBs from P1 to P2, or switch from a first SSB configuration to a second SSB configuration, wherein the first SSB configuration and the second SSB configuration are configured in the RRC messages at TO.

[0529] In an example, the wireless device, if the DCI indicating a deactivation of the SSB periodicity adaptation by setting the bit field to a second value (e.g., 0), may switch the periodicity of the SSBs from P2 to P1 , or switch from the second SSB configuration to the first SSB configuration.

[0530] In an example embodiment, the DCI is associated with a DCI format comprising a plurality of SSB periodicity adaptation indications.

[0531] In an example embodiment, the plurality of SSB periodicity adaptation indications are configured to be present in the DCI format according to an ascending order of cell indexes of the one or more cells. In this case, the right-most indication of the DCI format corresponds to a first cell with the lowest cell index, the second right-most indication corresponds to a second cell with the second lowest cell index, etc.

[0532] In an example embodiment, the plurality of SSB periodicity adaptation indications are configured to be present in the DCI format according to a descending order of cell indexes of the one or more cells. Inthis case, the right-most indication of the DCI format corresponds to a first cell with the highest cell index, the second right-most indication corresponds to a second cell with the second highest cell index, etc.

[0533] Based on example embodiments, predefining / preconfiguring the associations between the plurality of SSB periodicity adaptation indications and the plurality of cells, according to the ascending / descending order of cell indexes of the plurality of cells, may reduce signaling overhead for the configuration of the associations.

[0534] In an example embodiment, the RRC messages comprise a plurality of location indications for SSB periodicity adaptation indications of the one or more cells, wherein each location indication indicates, a location of a SSB periodicity adaptation indication, of the plurality of SSB periodicity adaptation indications in the DCI format, for a cell associated with the location indication.

[0535] In an example embodiment, different wireless devices may be associated with different location indications for SSB periodicity adaptation indications for one or more cells configured for different wireless devices. Example embodiments, by configuring UE-specific location indications for SSB periodicity adaptation indications (in a group common DCI) for one or more cells configured for a specific wireless device, may allow the base station to transmit the single group common DCI addressing to multiple wireless devices for SSB periodicity adaptation indications for one or more cells, although different wireless devices may be configured with different cells. Example embodiments may reduce signaling overhead for SSB periodicity adaptation indications for multiple wireless devices and multiple cells.

[0536] In an example embodiment, a SSB periodicity adaptation indication of a SCell may be present or absent in the DCI format. A size of a first SSB periodicity adaptation indication for a first cell is determined, by the base station and / or the wireless device, as: a non-zero value based on the first cell being configured with SSB periodicity adaptation; and a zero value based on the first cell not being configured with the SSB periodicity adaptation. Example embodiments, by determining a size of SSB periodicity adaptation indication in a DCI format based on whether the SSB periodicity adaptation is configured for a cell, may allow the base station and the wireless device to align the size of the DCI format, the location of the SSB periodicity adaptation indication, etc. Example embodiments may improve detection reliability of the DCI for the SSB periodicity adaptation indication.

[0537] In an example embodiment, a SSB periodicity adaptation indication of a SCell may be always present in the DCI format for the group common DCI. If the SCell is in an activated state and the wireless device receives the DCI format comprising an SSB periodicity adaptation indication (or activation) for the SCell, the wireless device may apply the SSB periodicity adaptation indication for the SCell (e.g., switching from P1 to P2, or switching from the first SSB configuration to the second SSB configuration). If the SCell is in a deactivated state and the wireless device receives the DCI format comprising an SSB periodicity adaptation indication (or activation) for the SCell, the wireless device may ignore the SSB periodicityadaptation indication for the SCell Example embodiments may improve power consumption of the wireless device for SSB reception / detection.

[0538] Example embodiments, by introducing a DCI format (with contents) indicating SSB periodicity adaptation for multiple cells and for multiple wireless devices, may reduce signaling overhead for SSB periodicity adaptation indications for multiple cells, therefore reducing power consumption of the base station and / or the wireless device.

[0539] In the example of FIG. 41 , the wireless device, after receiving the DCI at T2, may apply, starting from T3, a first SSB periodicity adaptation indication, of the plurality of SSB periodicity adaptation indications, for a first cell of the plurality of cells, based on: the first SSB periodicity adaptation indication being associated with the first cell and the first SSB periodicity adaptation indication indicating an SSB periodicity change.

[0540] In the example of FIG. 41 , the wireless device determines a time gap between T2 (or the last symbol of T2) and T3 (the first symbol of T3) based on at least one of: the wireless device’s capability for applying SSB periodicity adaptation; and / or indication from the base station. The wireless device determines the time gap is shorter than the application time / gap for OD-SSB trigger (e.g., based on examples of FIG. 36).

[0541] In the example of FIG. 41 , the wireless device determines that the adapted SSBs (with periodicity P2) are available no earlier than the time gap (or the end of the time gap) after T2. The wireless device starts to receive the adapted SSBs (with periodicity P2) no earlier than the time gap (or the end of the time gap) after T2. The wireless device determines that the SSBs are transmitted with the original / default SSB periodicity (P1 , or without the adaptation) before the end of the time gap after T2. The wireless device starts to receive the periodicity-adapted / changed (P2) SSBs, e.g., at T3 in FIG. 41 , which is after (or no earlier than) the end of the time gap starting from T2.

[0542] In an example embodiment, the time gap is determined in unit of slots, according to the SCS of the reference cell. The reference cell may be a cell on which the DCI is received, or the SCell for which the SSB periodicity adaptation indication is applied. In an example, the SCS may be determined as the lowest SCS among the cell (or an active BWP of the cell) on which the DCI is received, the SCell (or an active BWP of the SCell) for which the SSB periodicity adaptation indication is applied.

[0543] In an example, a SCS of a BWP / cell may be implemented based on examples of FIG. 7.

[0544] In an example embodiment, the wireless device transmits the wireless device capability information comprising one or more parameters indicating the (minimum) time gap for application of the SSB periodicity adaptation indication for a SCell (in an activated state). The (minimum) time gap for application of the SSB periodicity adaptation indication for a SCell (in an activated state) may be separately indicated from a time gap for application of the OD-SSB trigger for a SCell (in a deactivated state) comprised in the one or moreparameters. The time gap for application of the SSB periodicity adaptation indication may be shorter than the time gap for application of the OD-SSB trigger. The time gap for application of the OD-SSB trigger may be implemented based on examples of FIG. 36. The one or more parameters may be per frequency band indicated. The wireless device transmits wireless device capability information in response to receiving from the base station one or more RRC messages comprising a request of the wireless device capability information.

[0545] Example embodiments, by determining a minimum gap between the SSB periodicity adaptation indication and the starting of the adapted SSB transmission, may align the base station and the wireless device regarding the timing for the application of SSB periodicity adaptation indication for a cell, therefore reducing power consumption of the base station and / or the wireless device.

[0546] In the example of FIG. 41 , the wireless device receives the adapted SSBs with the second periodicity P2, from T3, after receiving the DCI indicating SSB periodicity adaptation for the SCell at T2.

[0547] In the example embodiment of FIG. 41 , based on receiving the SSB periodicity adaptation for the SCell in the activated state, the wireless device applies the SSB periodicity adaptation for the SCell, wherein the applying the SSB periodicity adaptation comprises receiving, via the SCell, the SSBs according to the second periodicity P2, or according to the second SSB configuration.

[0548] In an example embodiment, the wireless device may ignore the SSB periodicity adaptation indication (or may not apply the SSB periodicity adaptation indication) for the SCell based on receiving the SSB periodicity adaptation indication when the SCell is in the deactivated state

[0549] In an example embodiment, the wireless device, when receiving the SSBs with the second periodicity P2 (or according to the second SSB configuration) on the SCell (e.g., in the activated state), may determine to deactivate, e.g., at T4, the SCell based on receiving a SCell deactivation command (e.g., a SCell activation / deactivation MAC CE indicating the deactivation of the SCell) or based on an expiry of an SCell deactivation timer. The SCell deactivation command and / or the SCell deactivation timer may be implemented based on examples of FIG. 22.

[0550] In an example embodiment, the wireless device receives, via the SCell, the SSBs with the first periodicity P1 (or according to the first SSB configuration), based on the deactivating the SCell and / or determining that the SSB periodicity adaptation is not applicable for the SCell in the deactivated state.

[0551] In the example of FIG. 41 , the wireless device determines that the SSBs are transmitted by the base station with the first periodicity P1 (or according to the first SSB configuration) via the SCell in the deactivated state (starting from T4), even if the wireless device has not, (before T4 when the SCell is transitioned to the deactivated state), received another SSB periodicity adaptation indication indicating to switch the SSB periodicity to P1 , or indicating to switch to the first SSB configuration (with SSB periodicity configured as P1), or indicating a deactivation of the SSB periodicity adaptation.

[0552] Example embodiments may align the base station and the wireless device regarding the application of SSB periodicity adaptation indication for a SCell in different SCell states (e.g., activated state or deactivated state), therefore reducing power consumption of the base station and / or the wireless device.

[0553] The one or more examples of FIG. 41 may be extended to the case when the SCell is transitioned to a dormancy (e.g., switching an active BWP of the SCell to an RRC-configured dormant BWP of the SCell based on receiving a dormancy indication, comprised in a DCI, for the SCell).

[0554] In an example embodiment, the wireless device may ignore the SSB periodicity adaptation indication (or may not apply the SSB periodicity adaptation indication) for the SCell based on receiving the SSB periodicity adaptation indication when the SCell is in the dormancy (e.g., when the active DL BWP of the SCell is an RRC-configured dormant BWP and the SCell is activated). The wireless device may apply the SSB periodicity adaptation indication for the SCell based on receiving the SSB periodicity adaptation indication when the SCell is in the non-dormancy (e.g., when the active DL BWP of the SCell is a nondormant BWP and the SCell is activated). Example embodiments may align the base station and the wireless device regarding the application of SSB periodicity adaptation indication for an activated SCell in dormancy or in non-dormancy.

[0555] In an example embodiment, the wireless device determines that the SSBs are transmitted by the base station with the first periodicity P1 (or according to the first SSB configuration) via the SCell in the dormancy, even if the wireless device has not, (before the SCell is transitioned to the dormancy), received another SSB periodicity adaptation indication indicating to switch the SSB periodicity to P1 , or indicating to switch to the first SSB configuration (with SSB periodicity configured as P1), or indicating a deactivation of the SSB periodicity adaptation.

[0556] Example embodiments may align the base station and the wireless device regarding the application of SSB periodicity adaptation indication for a SCell in different states (e.g., dormancy or non- dormancy), therefore reducing power consumption of the base station and / or the wireless device.

[0557] According to FIG. 41 , one or more example embodiments comprise receiving, by a wireless device from a base station, one or more RRC messages comprising configuration parameters of a DCI with a DCI format comprising a plurality of SSB periodicity (or time-domain) adaptation indications. The configuration parameters indicate that each SSB periodicity indication, of the plurality of SSB periodicity (or time-domain) adaptation indications in the DCI format, is associated with a respective cell of a plurality of cells. Each SSB periodicity indication indicates an SSB periodicity adaptation for a corresponding cell of the plurality of cells. The wireless device receives the DCI with the DCI format comprising the plurality of SSB periodicity adaptation indications. The wireless device applies a first SSB periodicity adaptation indication, of the plurality of SSB periodicity adaptation indications, for a first cell of the plurality of cells, based on: the firstSSB periodicity adaptation indication being associated with the first cell and the first SSB periodicity adaptation indication indicating an SSB periodicity change.

[0558] According to an example embodiment, the plurality of SSB periodicity adaptation indications are present in the DCI format according to ascending order of cell indexes of the plurality of cells. In this case, the right-most indication of the DCI format corresponds to a first cell with the lowest cell index, the second right-most indication corresponds to a second cell with the second lowest cell index, etc.

[0559] According to an example embodiment, the plurality of SSB periodicity adaptation indications are present in the DCI format according to descending order of cell indexes of the plurality of cells. In this case, the right-most indication of the DCI format corresponds to a first cell with the highest cell index, the second right-most indication corresponds to a second cell with the second highest cell index, etc.

[0560] According to an example embodiment, the one or more RRC messages comprises a plurality of location indications for SSB periodicity adaptation indications of the plurality of cells, wherein each location indication indicates, a location of a SSB periodicity adaptation indication, of the plurality of SSB periodicity adaptation indications in the DCI format, for a cell associated with the location indication.

[0561] According to an example embodiment, a size of a first SSB periodicity adaptation indication for a first cell is determined as: a non-zero value based on the first cell being configured with SSB periodicity adaptation; and a zero value based on the first cell not being configured with the SSB periodicity adaptation.

[0562] Example embodiments may reduce signaling overhead for SSB periodicity adaptation indications for multiple cells, therefore reducing power consumption of the base station and / or the wireless device.

[0563] According to FIG. 41 , one or more example embodiments comprise receiving, by a wireless device from a base station, at a first time interval (e.g., a slot / symbol / subframe), a DCI comprising an SSB periodicity (or time-domain) adaptation indication for a cell. The wireless device determines a (minimum) time gap between the last symbol of the first time interval and a first symbol of an SSB transmission occasion based on at least one of: the wireless device's capability for applying SSB periodicity adaptation; and / or indication from the base station. The wireless device determines the time gap is shorter than the application time / gap for OD-SSB trigger. The wireless device determines that the adapted SSBs are available no earlier than the time gap after the last symbol of the first time interval. The wireless device starts to receive the adapted SSBs no earlier than the time gap after the last symbol of the first time interval. The wireless device determines that the SSBs are transmitted with the original / default SSB periodicity (or without the adaptation) before the time gap after the last symbol of the first time interval. The wireless device starts to receive the periodicity-adapted / changed SSBs after (or no earlier than) the time gap starting from the last symbol of the first time interval.

[0564] According to an example embodiment, the time gap is in unit of slots, according to the SCS of the reference cell. The reference cell may be a cell on which the DCI is received, or the SCell for which the SSB periodicity adaptation indication is applied. In an example, the SCS may be determined as the lowest SCS among the cell (or an active BWP of the cell) on which the DCI is received, the SCell (or an active BWP of the SCell) for which the SSB periodicity adaptation indication is applied.

[0565] According to an example embodiment, the wireless device transmits the wireless device capability information comprising one or more parameters indicating the (minimum) time gap for application of the SSB periodicity adaptation indication for a SCell (in an activated state). The (minimum) time gap for application of the SSB periodicity adaptation indication for a SCell (in an activated state) may be separately indicated from a time gap for application of the OD-SSB trigger for a SCell (in a deactivated state) comprised in the one or more parameters. The time gap for application of the SSB periodicity adaptation indication may be shorter than the time gap for application of the OD-SSB trigger. The one or more parameters may be per frequency band indicated. The wireless device transmits wireless device capability information in response to receiving from the base station one or more RRC messages comprising a request of the wireless device capability information.

[0566] Example embodiments may align the base station and the wireless device regarding the timing for the application of SSB periodicity adaptation indication for a cell, therefore reducing power consumption of the base station and / or the wireless device.

[0567] According to FIG 41 , one or more example embodiments comprise receiving, by a wireless device from a base station, one or more RRC messages comprising configuration parameters of SSBs of a SCell, wherein the configuration parameters indicate a first periodicity and a second periodicity. The wireless device receives, via the SCell, the SSBs with the first periodicity. The wireless device receives a command (e.g. , a group common DCI) indicating an SSB periodicity adaptation for the SCell. Based on the SCell being in an activated state and / or based on receiving the command, the wireless device applies the SSB periodicity adaptation for the SCell, wherein the applying the SSB periodicity adaptation comprises receiving, via the SCell, the SSBs with the second periodicity. In an example, the wireless device may ignore the SSB periodicity adaptation indication for the SCell based on receiving the SSB periodicity adaptation indication when the SCell is in the deactivated state. The wireless device, when receiving the SSBs with the second periodicity on the SCell (e.g., in the activated state), determines to deactivate the SCell based on receiving a SCell deactivation command or based on an expiry of an SCell deactivation timer. The wireless device receives, via the SCell, the SSBs with the first periodicity, based on the deactivating the SCell and / or determining that the SSB periodicity adaptation is not applicable for the SCell in the deactivated state.

[0568] / / Issue 2: how to apply the SSB periodicity adaptation indication when OD-SSBs are triggered on a SCell?

[0569] In first existing technologies (as shown in FIG. 38, FIG. 39A and / or FIG. 39B), SSB time-domain (or periodicity) adaptation (indicated by DCI) is used to change SSB periodicity, or switch between two SSB configurations. When configured with two SSB configurations, the base station may transmit SSBs with a first SSB configuration, in addition, the base station may use DCI to trigger, activate and / or deactivate the additional SSB configuration. It is disclosed that the SSB periodicity adaptation may be based on a MAC CE or a DCI (or a group common DCI).

[0570] In second existing technologies (as shown in FIG. 34, FIG. 35 and / or FIG. 36), a base station may trigger OD-SSBs for a SCell, e.g., for SCell activation. It is disclosed that the OD-SSBs may be triggered by an RRC message or a MAC CE and may be transmitted in a time period / window (e.g., from time instance A to time instance B as shown in FIG. 34).

[0571] However, based on the first existing technologies and / or the second existing technologies, it is unclear for a wireless device (or from the viewpoint of the wireless device) regarding how to apply the SSB periodicity adaptation indication when OD-SSBs are configured / triggered on a SCell. FIG. 42 shows example issues of the existing technologies for indicating / applying the SSB periodicity adaptation for one or more cells.

[0572] In the example of FIG. 42, a SCell may be configured with AO-SSBs (as case 2) or without AO- SSBs (as case 1), based on examples of FIG. 34. The base station, in addition to AO-SSBs, may trigger OD-SSBs on the SCell from A to B, based on examples of FIG. 34.

[0573] In the example of FIG. 42, when the OD-SSBs are triggered and transmitted from A to B, the base station may transmit an SSB periodicity (time-domain) adaptation indication for the SCell. The wireless device, in response to receiving the SSB periodicity adaptation indication, may have difficulties in determining how to apply the SSB periodicity adaptation indication for the SCell.

[0574] In an example, when AO-SSBs are configured on the SCell and transmitted with a first periodicity P1 (as shown in FIG. 42 as case 2), and when the OD-SSBs are triggered and transmitted with a second periodicity P2 on the SCell, in response to receiving an SSB periodicity adaptation indication, the wireless device, based on existing technologies, may have difficulties in determining how to deal with on-going AO- SSBs and / or OD-SSBs for the SSB periodicity adaptation indication, given that OD-SSB and AO-SSBs are transmitted with different periodicity (P1 for AO-SSBs and P2 for OD-SSBs) on the SCell. More specifically, the wireless device has no knowledge on whether (and / or how long) to apply the SSB periodicity adaptation indication on the AO-SSBs, the OD-SSBs, or both the AO-SSBs and the OD-SSBs of the SCell. Existing technologies may result in misalignment between the base station and the wireless device regarding the application of the SSB periodicity adaptation indication.

[0575] In an example, when AO-SSBs are not configured on the SCell (as shown in FIG. 42 as case 1 ), and when the OD-SSBs are triggered and transmitted with a second periodicity P2 on the SCell, in response to receiving an SSB periodicity adaptation indication, the wireless device, based on existing technologies, may have difficulties in determining how to deal with on-going OD-SSBs for the SSB periodicity adaptation indication. More specifically, the wireless device has no knowledge on whether to apply the SSB periodicity adaptation indication on the OD-SSBs of the SCell, and / or whether the OD-SSBs are stopped at time instance B or continued until receiving another SSB periodicity adaptation or OD-SSB trigger MAC CE, etc. Existing technologies may result in misalignment between the base station and the wireless device regarding the application of the SSB periodicity adaptation indication.

[0576] One or more example embodiments comprise determining, by the base station and / or the wireless device, whether the SSB periodicity adaptation indication is applied only to the AO-SSBs, or applied only to the OD-SSBs, or applied to both the AO-SSBs and the OD-SSBs, based on the RRC messages (MAC CE and / or DCI comprising the SSB periodicity adaptation indication) and / or preconfigured / predefined rule(s). Existing technologies may align between the base station and the wireless device regarding the application of the SSB periodicity adaptation indication.

[0577] One or more example embodiments comprise a wireless device not expecting that the base station transmits the SSB periodicity adaptation indication for the SCell when the OD-SSBs are triggered and transmitted on the SCell. The base station may transmit the SSB periodicity adaptation indication for the SCell after the OD-SSBs are stopped. By implementing the example embodiments, limiting the SSB periodicity adaptation to the time duration when the OD-SSBs are not triggered / transmitted and / or when the AO-SSBs are transmitted, may simplify the wireless device's implementation for receiving SSBs, therefore reducing power consumption of the wireless device.

[0578] FIG. 43 illustrates an example as per an aspect of an embodiment of the present disclosure.

[0579] In an example, a wireless device receives from a base station configuration parameters of a SCell. The configuration parameters may indicate that the SCell is configured with both AO-SSBs and OD-SSBs, e.g., based on examples of FIG. 37.

[0580] In an example, the AO-SSBs of the SCell may be cell defining (CD)-SSBs configured on initial DL BWP of the SCell. The AO-SSBs of the SCell may be non-cell-defining (NCD)-SSBs (e.g., which may be configured in a reduced capability (RedCap)-specific initial DL BWP of the SCell). In an example, the RedCap-specific initial DL BWP may be different from the initial DL BWP not specifically configured for a RedCap wireless device on the SCell.

[0581] In an example, the OD-SSBs may be configured on the same DL BWP (e.g., the initial DL BWP, or the Redcap-specific initial DL BWP) as the AO-SSBs on the SCell. The OD-SSBs may be configured as CD-SSBs or NCD-SSBs of the SCell.

[0582] In an example, the configuration parameters may further indicate that the SCell is configured with SSB periodicity adaptation, e.g., based on examples of FIG. 39A and / or FIG. 39B.

[0583] In the example of FIG. 43, when the SCell is configured and deactivated, the base station may transmit, and / or the wireless device may receive, the AO-SSBs with a first periodicity value (P1) according to Case 2 of FIG. 34.

[0584] In the example of FIG. 43, at T1 , the base station may transmit an OD-SSB trigger / command (e.g., a MAC CE) indicating transmission of the OD-SSBs on the SCell, based on examples of FIG. 35. The OD- SSBs may be transmitted from A to B, based on the OD-SSB trigger / command. The OD-SSBs may be periodically transmitted with a transmission periodicity P2 between A and B.

[0585] In the example of FIG. 43, at T2, the base station may transmit an SSB periodicity adaptation indication indicating an SSB periodicity adaptation for the SCell. The SSB periodicity adaptation indication may be comprised in a DCI.

[0586] In an example, the SSB periodicity adaptation indication for the SCell may be implemented based on example embodiments of FIG. 41.

[0587] In an example, the OD-SSB trigger / command (e.g., a MAC CE), received at T1 , may be different from the SSB periodicity adaptation indication (e.g., a DCI) received at T2.

[0588] In an example embodiment of FIG. 43, the wireless device and the base station may determine that the SSB periodicity adaptation indication is applicable for the OD-SSBs, in which case, the wireless device and / or the base station determines that the periodicity of the OD-SSBs are changed from P2 to P3 (which is configured by the configuration parameters of the SCell based on examples of FIG. 45, FIG. 46 and / or FIG. 47 which will be described later in this specification) and / or that the periodicity of the AO-SSBs are unchanged and maintained as R1 . In this case, the SSB periodicity adaptation indication is not applicable for the AO-SSBs. The wireless device may receive the OD-SSBs according to P3 and / or receive the AO-SSBs according to P1 from T2 on the SCell.

[0589] In an example embodiment, the wireless device and / or the base station may determine that the OD-SSBs are transmitted with P3 until receiving another SSB periodicity adaptation indication indicating that the SSB periodicity adaptation is disabled / deactivated. The SSB periodicity adaptation indication indicating that the SSB periodicity adaptation is disabled / deactivated may be received before time instance B or after time instance B. When the wireless device receives the SSB periodicity adaptation indication indicating that the SSB periodicity adaptation is disabled / deactivated, the wireless device may determine that the OD-SSBs are stopped. In this case, the SSB periodicity adaptation indication (received at T2) indicating an SSB periodicity adaptation for the SCell may override the OD-SSB trigger / command in terms of how long the OD-SSBs are transmitted.

[0590] In an example embodiment of FIG. 43, the wireless device and the base station may determine that the SSB periodicity adaptation indication is applicable for the AO-SSBs, in which case, the wireless device and / or the base station determines that the periodicity of the AO-SSBs are changed from P1 to P4 (which is configured by the configuration parameters of the SCell based on examples of FIG. 45, FIG. 46 and / or FIG. 47 which will be described later in this specification) and / or that the periodicity of the OD-SSBs are unchanged and maintained as P2. In this case, the SSB periodicity adaptation indication is not applicable for the OD-SSBs. The wireless device may receive the OD-SSBs according to P2 and / or receive the AO-SSBs according to P4 from T2 on the SCell.

[0591] In an example embodiment of FIG. 43, the wireless device and the base station may determine that the SSB periodicity adaptation indication is applicable for both the OD-SSBs and the AO-SSBs, in which case, the wireless device and / or the base station determines that the periodicity of the AO-SSBs are changed from P1 to P4 and the periodicity of the OD-SSBs are changed from P2 to P3 (which is configured by the configuration parameters of the SCell based on examples of FIG. 45, FIG. 46 and / or FIG. 47 which will be described later in this specification) and / or that the periodicity of the OD-SSBs are unchanged and maintained as P2 In this case, the wireless device may receive the OD-SSBs according to P3 and / or receive the AO-SSBs according to P4 from T2 on the SCell.

[0592] In an example embodiment, the wireless device and / or the base station determines whether the SSB periodicity adaptation indication is applied only to the AO-SSBs, or applied only to the OD-SSBs, or applied to both the AO-SSBs and the OD-SSBs, based on the RRC messages and / or preconfigured / predefined rule(s).

[0593] In an example embodiment, the wireless device may not expect the base station to transmit the SSB periodicity adaptation indication for the SCell when the OD-SSBs are triggered and transmitted on the SCell (e.g ., between time instance A and time instance B in FIG. 43). The base station may transmit the SSB periodicity adaptation indication for the SCell after time instance B where the OD-SSBs are stopped. By implementing the example embodiments, limiting the SSB periodicity adaptation to the time duration when the OD-SSBs are not triggered / transmitted and / or when the AO-SSBs are transmitted, may simplify the wireless device’s implementation for receiving SSBs, therefore reducing power consumption of the wireless device.

[0594] In an example embodiment, the base station and the wireless device may determine that the SSB periodicity adaptation indication is applied only for AO-SSBs on an SCell (e.g., after the OD-SSBs are stopped). When the SCell is not configured with AO-SSBs (or the SCell is an SSB-less SCell), the wireless device may ignore the SSB periodicity adaptation indication for the SCell.

[0595] In an example embodiment, the base station and the wireless device may determine that the SSB periodicity adaptation indication is applied only for AO-SSBs on an SCell (e.g., after the OD-SSBs arestopped). When the SCell is not configured with AO-SSBs (or the SCell is an SSB-less SCell) and / or when the SCell is not configured with SSB periodicity adaptation, the size of the SSB periodicity adaptation indication is zero in the DCI. When the SCell is configured with AO-SSBs and the SCell is configured with SSB periodicity adaptation indication, the size of the SSB periodicity adaptation indication is a non-zero value (e.g., 1 bit) in the DCI.

[0596] Based on example embodiments of FIG. 43, the base station and the wireless device are aligned regarding how to apply the SSB periodicity adaptation indication for a SCell when AO-SSB and OD-SSBs are transmitted on the SCell.

[0597] FIG. 44 illustrates an example as per an aspect of an embodiment of the present disclosure.

[0598] In an example, a wireless device receives from a base station configuration parameters of a SCell. The configuration parameters may indicate that the SCell is configured with OD-SSBs, wherein the SCell is not configured with AO-SSBs, e.g., based on examples of FIG. 34 (e.g., Case 1 of FIG. 34).

[0599] In an example, the OD-SSBs may be configured on the initial DL BWP of the SCell. The OD-SSBs may be configured as cell defining (CD)-SSBs or non-cell-defining (NCD)-SSBs of the SCell.

[0600] In an example, the configuration parameters may further indicate that the SCell is configured with SSB periodicity adaptation, e.g., based on examples of FIG. 39A and / or FIG. 39B.

[0601] In the example of FIG. 44, at T1 , the base station may transmit an OD-SSB trigger / command (e.g., a MAC CE) indicating transmission of the OD-SSBs on the SCell, e.g., based on examples of FIG. 34 (for Case 1). The OD-SSBs may be transmitted from A to B, based on the OD-SSB trigger / command. The OD- SSBs may be periodically transmitted with a transmission periodicity P2 between A and B.

[0602] In the example of FIG. 44, at T2, the base station may transmit an SSB periodicity adaptation indication indicating an SSB periodicity adaptation for the SCell. The SSB periodicity adaptation indication may be comprised in a DCI.

[0603] In an example, the SSB periodicity adaptation indication for the SCell may be implemented based on example embodiments of FIG. 41.

[0604] In an example, the OD-SSB trigger / command (e.g., a MAC CE), received at T1 , may be different from the SSB periodicity adaptation indication (e.g., a DCI) received at T2.

[0605] In an example embodiment of FIG. 44, the wireless device and the base station may determine that the SSB periodicity adaptation indication is applicable for the OD-SSBs, in which case, the wireless device and / or the base station determines that the periodicity of the OD-SSBs are changed from P2 to P3 (which is configured by the configuration parameters of the SCell based on examples of FIG. 45, FIG. 46 and / or FIG. 47 which will be described later in this specification). The wireless device may receive the OD- SSBs according to P3 from T2 on the SCell.

[0606] In an example embodiment of FIG. 44, at time instance B, the wireless device and the base station may determine that the periodicity-adapted OD-SSBs are stopped. The wireless device may stop receiving the periodicity-adapted OD-SSBs at time instance B.

[0607] In an example embodiment, the wireless device and / or the base station may determine that the OD-SSBs are transmitted with P3 (regardless of time instance B) until receiving another SSB periodicity adaptation indication indicating that the SSB periodicity adaptation is disabled / deactivated. The SSB periodicity adaptation indication indicating that the SSB periodicity adaptation is disabled / deactivated may be received before time instance B or after time instance B. When the wireless device receives the SSB periodicity adaptation indication indicating that the SSB periodicity adaptation is disabled / deactivated, the wireless device may determine that the OD-SSBs are stopped. In this case, the SSB periodicity adaptation indication (received at T2) indicating an SSB periodicity adaptation for the SCell may override the OD-SSB trigger / command (received at T1) in terms of how long the OD-SSBs are transmitted.

[0608] In an example embodiment, the base station and / or the wireless device determines whether the SSB periodicity adaptation indication is applied to the OD-SSBs after time instance B, based on the RRC messages and / or preconfigured / predefined rule(s).

[0609] In an example, when the SSB periodicity adaptation indication is applied to the OD-SSBs before time instance B, the wireless device and / or the base station determines that the OD-SSBs are transmitted with P3 from T2 to time instance B and are stopped at time instance B.

[0610] In an example, when the SSB periodicity adaptation indication is applied to the OD-SSBs regardless of time instance B and is stopped when receiving another SSB periodicity adaptation indication indicating that the SSB periodicity adaptation is disabled / deactivated, the wireless device and / or the base station determines that the OD-SSBs are transmitted with P3 from T2 to a time interval (which may be before time instance B or after time instance B) when receiving the another SSB periodicity adaptation indication indicating that the SSB periodicity adaptation is disabled / deactivated.

[0611] In an example, the base station and / or the wireless device may determine that the periodicity- adapted OD-SSBs are stopped at the earliest of: time instance B; and a time interval when receiving the another SSB periodicity adaptation indication indicating that the SSB periodicity adaptation is disabled / deactivated.

[0612] In an example embodiment, the wireless device may not expect the base station to transmit the SSB periodicity adaptation indication for the SCell when the OD-SSBs are triggered and transmitted on the SCell (e.g., between time instance A and time instance B in FIG. 44). The base station may transmit the SSB periodicity adaptation indication for the SCell after time instance B where the OD-SSBs are stopped. By implementing the example embodiments, limiting the SSB periodicity adaptation to the time durationwhen the OD-SSBs are not triggered / transmitted, may simplify the wireless device's implementation for receiving SSBs, therefore reducing power consumption of the wireless device.

[0613] In an example embodiment, the base station and the wireless device may determine that the SSB periodicity adaptation indication is applied for an SCell when the SCell is configured at least with OD-SSBs. When the SCell is not configured with OD-SSBs (with or without AO-SSBs), the wireless device may ignore the SSB periodicity adaptation indication for the SCell.

[0614] In an example embodiment, the base station and the wireless device may determine that the SSB periodicity adaptation indication is applied for an SCell when the SCell is configured at least with OD-SSBs. When the SCell is not configured with OD-SSBs (with or without AO-SSBs) and / or when the SCell is not configured with SSB periodicity adaptation, the size of the SSB periodicity adaptation indication is zero in the DCI. When the SCell is configured with OD-SSBs and the SCell is configured with SSB periodicity adaptation indication, the size of the SSB periodicity adaptation indication is a non-zero value (e.g., 1 bit) in the DCI.

[0615] In an example embodiment, when receiving the SSB periodicity adaptation at T2, the wireless device may delay applying or may ignore the SSB periodicity adaptation for the SCell, e.g , when the SCell is not activated yet, or during the activation of the SCell, if the SSB periodicity adaptation for the SCell is received during the activation of the SCell. A time duration for the activation of the SCell may comprise a time duration between receiving a SCell activation command and completing the SCell activation.

[0616] Based on example embodiments of FIG 44, the base station and the wireless device are aligned regarding how to apply the SSB periodicity adaptation indication for a SCell when AO-SSB and OD-SSBs are transmitted on the SCell.

[0617] FIG. 45 shows an example of RRC configuration of SSB periodicity adaptation of a cell configured with OD-SSBs, e.g., based on examples of FIG. 43 and / or FIG. 44. A wireless device may receive from a base station one or more RRC messages comprising the RRC configuration of the SSB periodicity adaptation of the cell configured with OD-SSBs. In an example, the one or more RRC messages may comprise a ServingCellConfigCommon IE.

[0618] In the example of FIG. 45, a ServingCellConfigCommon IE of a cell may comprise parameters of SSBs of the cell. The parameters may comprise ssb-Position In Burst, ssb-periodicityServingCell, ssbSubcarrierSpacing, ss-PBCH-BlockPower, etc. The frequency location of the SSBs may be indicated by absoluteFrequencySSB configured in FrequencylnfoDL as shown in FIG. 33. The SSBs transmitted according to the parameters may be referred to as AO-SSBs of the cell in this specification.

[0619] In the example of FIG. 45, the parameters may further comprise additional-ssb-periodicity indicating an additional periodicity value for SSB periodicity adaptation. The value of additional-ssb- periodicity may be shorter / smaller the value of ssb-periodicityServingCell.

[0620] In an example, the additional-ssb-periodicity of the ServingCellConfigCommon IE may be only applicable for the AO-SSBs of the cell.

[0621] In the example of FIG. 45, the ServingCellConfigCommon IE of the cell may further comprise an OnDemand-SSB-Config IE indicating configuration parameters of OD-SSBs of the cell.

[0622] In the example of FIG. 45, the configuration parameters of the OD-SSBs of the cell may comprise absoluteFrequencySSB, ssb-PositionlnBurst, ssbSubcarrierSpacing, ss-PBCH-BlockPower, ssb- periodicityServingCell, etc., for the OD-SSBs of the cell. The configuration parameters of the OD-SSBs may further comprise additional-ssb-periodicity indicating an additional periodicity value for SSB periodicity adaptation. The value of additional-ssb-periodicity may be shorter / smaller than the value of ssb- periodicityServingCell of the OnDemand-SSB-Config IE.

[0623] In the example embodiments of FIG. 45, an additional SSB periodicity value is configured separately for AO-SSBs and OD-SSBs of the cell, so that the base station may adapt SSB periodicity of AO-SSBs and OD-SSBs separately. Example embodiments may allow the base stion to flexibly adapt SSB periodicity of the AO-SSBs and the OD-SSBs of the cell.

[0624] In an example embodiment, the additional-ssb-periodicity may be absent in the OnDemand-SSB- Config IE of the cell. When the SSB periodicity adaptation is indicated, the base station may transmit (and / or the wireless device may receive) the OD-SSBs with SSB periodicity adapted to a value indicated by the additional-ssb-periodicity of the ServingCellConfigCommon IE of the cell when applying the SSB periodicity adaptation or adaption to the OD-SSBs. The base station may transmit (and / or the wireless device may receive) the AO-SSBs with SSB periodicity adapted to a value indicated by the additional-ssb- periodicity of the ServingCellConfigCommon IE of the cell when applying...

Claims

1. CLAIMSWhat is claimed is:

1. A method comprising: receiving, by a wireless device, one or more radio resource control (RRC) messages comprising: a synchronization signal block (SSB) periodicity value of SSBs of a first cell of a plurality of cells; one or more additional SSB periodicity values, of the SSBs of the first cell, associated with adaptation of SSB periodicity; and a position indication of a first SSB periodicity indication, of one or more SSB periodicity indications for the plurality of cells in a downlink control information (DCI) for the adaptation of the SSB periodicity, corresponding to the first cell; receiving the DCI with a DCI format 2_9 comprising the one or more SSB periodicity indications for the adaptation of the SSB periodicity, wherein the first SSB periodicity indication is present among the one or more SSB periodicity indications, in the DCI format 2_9 for the first cell, based on the one or more additional SSB periodicity values being configured for the first cell; and receiving, based on the DCI and via the first cell, the SSBs with a first additional SSB periodicity value indicated by the first SSB periodicity indication determined based on the position indication and from the one or more SSB periodicity indications.

2. A method comprising: receiving, by a wireless device, one or more radio resource control (RRC) messages comprising: a synchronization signal block (SSB) periodicity value of SSBs of a first cell of a plurality of cells; one or more additional SSB periodicity values, of the SSBs of the first cell, associated with adaptation of SSB periodicity; and a position indication of a first SSB periodicity indication, of one or more SSB periodicity indications in a downlink control information (DCI) for the adaptation of the SSB periodicity, corresponding to the first cell; receiving the DCI comprising the one or more SSB periodicity indications for the adaptation of the SSB periodicity, wherein the first SSB periodicity indication in the one or more SSB periodicity indications corresponds to the first cell based on the position indication; and receiving, based on the DCI and via the first cell, the SSBs with a first additional SSB periodicity value indicated by the first SSB periodicity indication.

3. A method comprising:receiving, by a wireless device, a downlink control information (DCI) comprising one or more synchronization signal block (SSB) periodicity indications indicating an adaptation of SSB periodicity of one or more secondary cells (SCells), wherein: a first SSB periodicity indication is present, among the one or more SSB periodicity indications, for a first SCell of the one or more SCells, based on one or more first additional SSB periodicity values being configured for the first SCell for the adaptation of SSB periodicity; and a second SSB periodicity indication is absent, among the one or more SSB periodicity indications, for a second SCell of the one or more SCells, based on one or more second additional SSB periodicity values not being configured for the second SCell for the adaptation of SSB periodicity; and receiving, based on the DCI and via the first SCell, one or more SSBs with a first additional SSB periodicity value indicated by the first SSB periodicity indication and from the one or more first additional SSB periodicity values of the first SCell.

4. A method comprising: receiving, by a wireless device, one or more radio resource control (RRC) messages comprising: a synchronization signal block (SSB) periodicity value of SSBs of a first cell; one or more additional SSB periodicity values of the SSBs of the first cell; and one or more on-demand SSB periodicity values of on-demand SSBs of the first cell; receiving a downlink control information (DCI) comprising a SSB periodicity indication for an adaptation of SSB periodicity of the first cell, wherein the adaptation of SSB periodicity is applied, for the SSBs, among the SSB periodicity value and the one or more additional SSB periodicity values; and receiving, based on the DCI and via the first cell, the SSBs with a first additional SSB periodicity value indicated by the SSB periodicity indication from: the SSB periodicity value; and the one or more additional SSB periodicity values.

5. A method comprising: sending, by a base station to a wireless device, one or more radio resource control (RRC) messages comprising: a synchronization signal block (SSB) periodicity value of SSBs of a first cell of a plurality of cells; one or more additional SSB periodicity values, of the SSBs of the first cell, associated with adaptation of SSB periodicity; anda position indication of a first SSB periodicity indication, of one or more SSB periodicity indications for the plurality of cells in a downlink control information (DCI) for the adaptation of the SSB periodicity, corresponding to the first cell; receiving the DCI with a DCI format 2_9 comprising the one or more SSB periodicity indications for the adaptation of the SSB periodicity, wherein the first SSB periodicity indication is present among the one or more SSB periodicity indications, in the DCI format 2_9 for the first cell, based on the one or more additional SSB periodicity values being configured for the first cell; and receiving, based on the DCI and via the first cell, the SSBs with a first additional SSB periodicity value indicated by the first SSB periodicity indication determined based on the position indication and from the one or more SSB periodicity indications.

6. A method comprising: sending, by a base station to a wireless device, one or more radio resource control (RRC) messages comprising: a synchronization signal block (SSB) periodicity value of SSBs of a first cell of a plurality of cells; one or more additional SSB periodicity values, of the SSBs of the first cell, associated with adaptation of SSB periodicity; and a position indication of a first SSB periodicity indication, of one or more SSB periodicity indications in a downlink control information (DCI) for the adaptation of the SSB periodicity, corresponding to the first cell; sending the DCI comprising the one or more SSB periodicity indications for the adaptation of the SSB periodicity, wherein the first SSB periodicity indication in the one or more SSB periodicity indications corresponds to the first cell based on the position indication; and sending, based on the DCI and via the first cell, the SSBs with a first additional SSB periodicity value indicated by the first SSB periodicity indication.

7. A method comprising: sending, by a base station to a wireless device, a downlink control information (DCI) comprising one or more synchronization signal block (SSB) periodicity indications indicating an adaptation of SSB periodicity of one or more secondary cells (SCells), wherein: a first SSB periodicity indication is present, among the one or more SSB periodicity indications, for a first SCell of the one or more SCells, based on one or more first additional SSB periodicity values being configured for the first SCell for the adaptation of SSB periodicity; and a second SSB periodicity indication is absent, among the one or more SSB periodicity indications, for a second SCell of the one or more SCells, based on one or more second additionalSSB periodicity values not being configured for the second SCell for the adaptation of SSB periodicity; and sending, based on the DCI and via the first SCell, one or more SSBs with a first additional SSB periodicity value indicated by the first SSB periodicity indication and from the one or more first additional SSB periodicity values of the first SCell.

8. A method comprising: sending, by a base station to a wireless device, one or more radio resource control (RRC) messages comprising: a synchronization signal block (SSB) periodicity value of SSBs of a first cell; one or more additional SSB periodicity values of the SSBs of the first cell; and one or more on-demand SSB periodicity values of on-demand SSBs of the first cell; sending a downlink control information (DCI) comprising a SSB periodicity indication for an adaptation of SSB periodicity of the first cell, wherein the adaptation of SSB periodicity is applied, for the SSBs, among the SSB periodicity value and the one or more additional SSB periodicity values; and sending, based on the DCI and via the first cell, the SSBs with a first additional SSB periodicity value indicated by the SSB periodicity indication from: the SSB periodicity value; and the one or more additional SSB periodicity values.

9. The method of any one of claims 1 to 8, wherein the wireless device receives, the SSBs via the first cell, a first number of slots after the wireless device receives the DCI, wherein the first number of slots is determined based on a subcarrier spacing (SCS) of an active downlink bandwidth part (BWP), of a serving cell, on which the DCI is received by the wireless device.

10. The method of claim 9, wherein the first number is a predefined value based on the SCS of the active downlink BWP on which the DCI is received by the wireless device.11 . The method of claim 9, wherein the first number of slots for applying the adaptation of SSB periodicity is same as a time duration / gap for applying a cell discontinuous transmission (DTX) activation / deactivation command.

12. The method of any one of claims 1 to 11 , wherein the first SSB periodicity indication indicates the first additional SSB periodicity value from the one or more additional SSB periodicity values, associated with the adaptation of SSB periodicity, based on the first SSB periodicity indication being set to a nonzero value.

13. The method of any one of claims 1 to 12, wherein the first SSB periodicity indication set to a zero value indicates the SSB periodicity value.

14. The method of any one of claims 1 to 13, wherein the first SSB periodicity indication is different from a cell discontinuous transmission (cell DTX) activation / deactivation indication.

15. The method of any one of claims 1 to 14, wherein the adaptation of SSB periodicity indication is applied to the SSBs of the first cell, wherein the SSBs are not configured as cell defining SSBs (CD- SSBs) on the first cell.

16. The method of claim 15, wherein in response to receiving the DCI comprising the first SSB periodicity indication for the first cell, the wireless device receives, via the first cell, the SSBs with the first additional SSB periodicity value based on the SSBs not being configured as the CD-SSBs on the first cell.

17. The method of any one of claims 1 to 4 or 9 to 16, further comprising receiving a second DCI with the DCI format 2_9.

18. The method of claim 17, further comprising receiving, via the first cell, the SSBs with the SSB periodicity value based on: the first SSB periodicity indication being set to a zero value in the second DCI; and the first SSB periodicity indication determined based on the position indication and among the one or more SSB periodicity indications.

19. The method of any one of claims 1 to 18, wherein the one or more RRC messages comprise configuration parameters of one or more on-demand SSB (OD-SSB) configurations of the first cell, wherein each OD-SSB configuration of the one or more OD-SSB configurations is associated with an OD-SSB periodicity value.

20. The method of claim 19, further comprising: receiving a medium access control control element (MAC CE) indicating an activation of a first OD- SSB configuration of the one or more OD-SSB configurations of the first cell; and starting to receive, based on the MAC CE and via the first cell, one or more OD-SSBs based on a first OD-SSB periodicity value of the first OD-SSB configuration.21 . The method of claim 20, wherein the wireless device starts, to receive the one or more OD-SSBs via the first cell, a second number of slots after the wireless device transmits a hybrid automatic repeat request acknowledgement (HARQ-ACK) feedback corresponding to the reception of the MAC CE.

22. The method of claim 21 , wherein the second number of slots, for applying the activation of the first OD-SSB configuration indicated by the MAC CE, is different from the first number of slots for applying the adaptation of SSB periodicity indicated by the DCI.

23. The method of claim 20, further comprising determining whether the first SSB periodicity indication of the DCI is applied for the one or more OD-SSB configurations of the first cell.

24. The method of claim 23, wherein the wireless device determines that the first SSB periodicity indication of the DCI is not applied for the one or more OD-SSB configurations of the first cell.

25. The method of claim 23, wherein the first SSB periodicity indication not being applied for the one or more OD-SSB configurations comprises in response to the first OD-SSB configuration being activated on the first cell and after (or regardless of whether) the first SSB periodicity indication for the first cell is received in the DCI, continuing receiving, via the first cell, the one or more OD-SSBs based on the first OD-SSB periodicity value according to the first OD-SSB configuration.

26. The method of claim 23, wherein the wireless device determines that the first SSB periodicity indication of the DCI is applied for the SSBs of the first cell.

27. The method of claim 26, wherein the first SSB periodicity indication of the DCI being applied for the SSBs of the first cell comprises adapting / changing, based on the first SSB periodicity indication of the DCI, the SSB periodicity of the SSBs of the first cell among the SSB periodicity value and the one or more additional SSB periodicity values.

28. The method of any one of claims 1 to 27, wherein the first cell and a second cell are SCells.

29. The method of any one of claims 1 to 28, wherein a size of a SSB periodicity indication, in the DCI and for a cell of the plurality of cells, is determined as: a non-zero value based on the cell being configured with the adaptation of SSB periodicity; and a zero value based on the cell not being configured with the adaptation of SSB periodicity.

30. The method of claim 29, wherein: the SSB periodicity indication is present in the DCI based on the size of the SSB periodicity indication being the non-zero value; and the SSB periodicity indication is absent in the DCI based on the size of the SSB periodicity indication being the zero value.31 . The method of claim 29, wherein the cell being configured with the adaptation of SSB periodicity comprises the cell being configured with one or more additional SSB periodicity values, in addition to an SSB periodicity value.

32. The method of claim 29, wherein the cell not being configured with the adaptation of SSB periodicity comprises in addition to being configured with the SSB periodicity value, the cell not being configured with the one or more additional SSB periodicity values.

33. The method of any one of claims 1 to 32, wherein the one or more RRC messages comprise: a second SSB periodicity value of a second cell of the plurality of cells; one or more second additional SSB periodicity values, of the second cell, associated with the adaptation of SSB periodicity; anda second location indication of a second SSB periodicity indication, of the one or more SSB periodicity indications in the DCI for the adaptation of the SSB periodicity, corresponding to the second cell of the plurality of cells.

34. The method of claim 33, wherein the second SSB periodicity indication is present among the one or more SSB periodicity indications, in the DCI format 2_9 for the second cell, based on the one or more second additional SSB periodicity values being configured for the second cell.

35. The method of claim 34, further comprising receiving, based on the DCI and via the second cell, second SSBs with a second additional SSB periodicity value indicated by the second SSB periodicity indication from the one or more second additional SSB periodicity values, based on a second position indication, of the one or more SSB periodicity indications.

36. The method of any one of claims 1 to 35, wherein a third SSB periodicity indication is not present among the one or more SSB periodicity indications, in the DCI format 2_9 for a third cell of the plurality of cells, based on no additional SSB periodicity values being configured for the third cell.

37. The method of any one of claims 1 to 36, wherein the DCI is a group common DCI.

38. The method of any one of claims 1 to 4 or 9 to 37, further comprising receiving, based on receiving the one or more RRC messages, via the first cell, the SSBs with the SSB periodicity value.

39. The method of claim 38, wherein the wireless device receives, via the first cell, the SSBs with the SSB periodicity value before an application of the first SSB periodicity indication of the DCI, wherein: the application of the first SSB periodicity indication is employed at least a first number of slots after the reception of the DCI; and the first number is determined based on a subcarrier spacing (SCS) of an active downlink BWP, of a serving cell, on which the DCI is received.

40. The method of any one of claims 1 to 39, wherein the one or more RRC messages comprise configuration parameters of the SSBs of t4he first cell, wherein the configuration parameters comprise at least one of: the SSB periodicity value; the one or more additional SSB periodicity values; a SCS value; a SSB transmission power value; a frequency location indication; and a SSB position in burst indication.41 . The method of claim 40, wherein the one or more RRC messages comprise second configuration parameters of one or more OD-SSBs of an OD-SSB configuration of the first cell, wherein the second configuration parameters comprise at least one of:an OD-SSB periodicity value; an OD-SSB SCS value; an OD-SSB transmission power value; an OD-SSB frequency location indication; and an OD-SSB position in burst indication.

42. The method of claim 41 , wherein: the adaptation of SSB periodicity is applied / employed among the SSB periodicity value and the one or more additional SSB periodicity values for the SSBs; and the adaptation of SSB periodicity is not applied / employed for the OD-SSB periodicity value for the one or more OD-SSBs.

43. The method of any one of claims 1 to 42, wherein the adaptation of SSB periodicity is configured for a network energy saving (NES) of the base station.

44. An apparatus comprising: one or more processors; and memory storing instructions that, when executed by the one or more processors, cause the apparatus to perform the method of any one of claims 1 to 43.

45. A non-transitory computer-readable medium comprising instructions that, when executed by one or more processors of an apparatus, cause the apparatus to perform the method of any one of claims 1 to 43

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