Valid rach resource determination with on-demand SSB change

Abstract

A method comprises transmitting, by a wireless device, a preamble via a physical random access channel (PRACH) occasion. The PRACH occasion is determined based on a first periodicity and a second periodicity. One or more first on-demand synchronization signal blocks (OD-SSBs) are transmitted based on the first periodicity and one or more second OD-SSBs are transmitted based on the second periodicity.

Description

Docket No.: 24-1227PCT TITLE Valid Rach Resource Determination with On-Demand SSB Change CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No.63 / 701,817, filed October 1, 2024 and U.S. Provisional Application No.63 / 802,122, filed May 8, 2025, each of 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.1B 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 ion 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 more PUCCH groups.

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

[0016] FIG.11B 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.Docket No.: 24-1227PCT

[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.17 illustrates an aspect of an example embodiment according to the present disclosure.

[0024] FIG.18 illustrates an aspect of an example embodiment 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 illustrates an aspect of an example embodiment 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.24 illustrates an aspect of an example embodiment 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. DETAILED DESCRIPTION

[0036] 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 andDocket No.: 24-1227PCT 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.

[0037] 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.

[0038] 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. Wireless devices 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.

[0039] 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.Docket No.: 24-1227PCT

[0040] 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 = {cell1, cell2} are: {cell1}, {cell2}, and {cell1, 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 the phrase “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.

[0041] 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.

[0042] In this disclosure, parameters (or equally called, fields, or Information elements: IEs) 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.

[0043] 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 theDocket No.: 24-1227PCT three possible features, with any two of the three possible features or with three of the three possible features.

[0044] 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-specific integrated 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.

[0045] FIG.1A 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.

[0046] 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.

[0047] 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. DownlinkDocket No.: 24-1227PCT transmissions may be separated from uplink transmissions using frequency division duplexing (FDD), time- division duplexing (TDD), and / or some combination of the two duplexing techniques.

[0048] 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 (IoT) 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.

[0049] 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 to extend 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).

[0050] 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.

[0051] 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 / similarDocket No.: 24-1227PCT 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.

[0052] 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.

[0053] 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.

[0054] FIG.1B 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.1B, 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.1A.

[0055] 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 networkDocket No.: 24-1227PCT 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).

[0056] As illustrated in FIG.1B, 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.1B 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 PDU session. The UEs 156 may be configured to receive services through a PDU session, which is a logical connection between a UE and a DN.

[0057] 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.

[0058] The 5G-CN 152 may include one or more additional network functions that are not shown in FIG. 1B 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).

[0059] 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 ofDocket No.: 24-1227PCT 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.

[0060] As shown in FIG.1B, 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.1B, 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.1B 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.

[0061] 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.

[0062] 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.

[0063] 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). AlthoughDocket No.: 24-1227PCT only one AMF / UPF 158 is shown in FIG.1B, 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.

[0064] As discussed, an interface (e.g., Uu, Xn, and NG interfaces) between the network elements in FIG. 1B 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.

[0065] 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.1B.

[0066] 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 Open Systems Interconnection (OSI) 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.

[0067] 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.

[0068] 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 messagesDocket No.: 24-1227PCT 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-gNB 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.

[0069] 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.

[0070] 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. The RLCs 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.

[0071] 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.

[0072] 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.Docket No.: 24-1227PCT 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.

[0073] 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.

[0074] 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 in FIG.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.

[0075] 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.

[0076] 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.

[0077] FIG.4B further illustrates MAC control elements (CEs) inserted into the MAC PDU by a MAC, such as MAC 223 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) andDocket No.: 24-1227PCT 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.

[0078] 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.

[0079] 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 the RLC, 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 include, for example:

[0080] -- 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;

[0081] -- a broadcast control channel (BCCH) for carrying system information messages in the form of a master information block (MIB) 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;

[0082] -- a common control channel (CCCH) for carrying control messages together with random access;

[0083] -- a dedicated control channel (DCCH) for carrying control messages to / from a specific the UE to configure the UE; and

[0084] -- a dedicated traffic channel (DTCH) for carrying user data to / from a specific the UE.

[0085] 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 include, for example:

[0086] -- a paging channel (PCH) for carrying paging messages that originated from the PCCH;Docket No.: 24-1227PCT

[0087] -- a broadcast channel (BCH) for carrying the MIB from the BCCH;

[0088] -- a downlink shared channel (DL-SCH) for carrying downlink data and signaling messages, including the SIBs from the BCCH;

[0089] -- an uplink shared channel (UL-SCH) for carrying uplink data and signaling messages; and

[0090] -- a random access channel (RACH) for allowing a UE to contact the network without any prior scheduling.

[0091] 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 include, for example:

[0092] -- a physical broadcast channel (PBCH) for carrying the MIB from the BCH;

[0093] -- 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;

[0094] -- 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;

[0095] -- 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;

[0096] -- a physical uplink control channel (PUCCH) for carrying UCI, which may include HARQ acknowledgments, channel quality indicators (CQI), pre-coding matrix indicators (PMI), rank indicators (RI), and scheduling requests (SR); and

[0097] -- a physical random access channel (PRACH) for random access.

[0098] 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.

[0099] 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 ofDocket No.: 24-1227PCT 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.

[0100] 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.

[0101] 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 radio bearers and the same / similar PDCP, RLC, MAC, and PHY protocol layers. The MAC may multiplex control- plane 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.

[0102] 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_IDLE), and RRC inactive 606 (e.g., RRC_INACTIVE).

[0103] 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.1B, 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 baseDocket No.: 24-1227PCT 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.

[0104] 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., once in 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.

[0105] 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.

[0106] 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 byDocket No.: 24-1227PCT 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).

[0107] 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.

[0108] 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.

[0109] 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.

[0110] A gNB, such as gNBs 160 in FIG.1B, 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.

[0111] 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 time- domain 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 aDocket No.: 24-1227PCT 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.

[0112] 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.

[0113] 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 be defined 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 µs. For example, NR defines numerologies with the following subcarrier spacing / cyclic prefix duration combinations: 15 kHz / 4.7 µs; 30 kHz / 2.3 µs; 60 kHz / 1.2 µs; 120 kHz / 0.59 µs; and 240 kHz / 0.29 µs.

[0114] 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.

[0115] 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 275×12 = 3300 subcarriers. Such a limitation, if used, may limit the NR carrier to 50, 100, 200, and 400 MHz for subcarrier spacingsDocket No.: 24-1227PCT 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.

[0116] 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.

[0117] 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.

[0118] 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 uplink BWPs 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.

[0119] 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.

[0120] 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.

[0121] 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).Docket No.: 24-1227PCT

[0122] 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.

[0123] 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.

[0124] 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 spectra operation. 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.

[0125] 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).

[0126] 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.

[0127] 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 aDocket No.: 24-1227PCT 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.

[0128] 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.

[0129] 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.

[0130] 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).

[0131] 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.

[0132] 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 otherDocket No.: 24-1227PCT 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).

[0133] 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).

[0134] 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 self- scheduling. 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 RI) 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.

[0135] 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 UCI 1031, UCI 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, UCI 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.Docket No.: 24-1227PCT

[0136] 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.

[0137] 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. A transport block and potential HARQ retransmissions of the transport block may be mapped to a serving cell.

[0138] 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.

[0139] 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.

[0140] 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.11A) 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 centerDocket No.: 24-1227PCT 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.

[0141] 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 a synchronization raster. In an example, a cell selection / search and / or reselection may be based on the CD- SSB.

[0142] 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.

[0143] 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.

[0144] 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, averageDocket No.: 24-1227PCT 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.

[0145] 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.

[0146] 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.

[0147] 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 estimation or 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.

[0148] 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.

[0149] 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.

[0150] 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 downlinkDocket No.: 24-1227PCT 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.

[0151] 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 4 orthogonal 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.

[0152] 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).

[0153] 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.

[0154] 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 oneDocket No.: 24-1227PCT 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.

[0155] 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 base station 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.

[0156] 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.

[0157] 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.

[0158] 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 mayDocket No.: 24-1227PCT 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 SRS triggered 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 PUSCH and SRS are transmitted in a same slot, the UE may be configured to transmit SRS after a transmission of a PUSCH and a corresponding uplink DMRS.

[0159] 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 OFDM symbols in an SRS resource; a starting OFDM symbol of an SRS resource; an SRS bandwidth; a frequency hopping bandwidth; a cyclic shift; and / or an SRS sequence ID.

[0160] 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.

[0161] 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 moreDocket No.: 24-1227PCT reference signals. For 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.

[0162] FIG.11B illustrates an example of channel state information reference signals (CSI-RSs) that are mapped in the time and frequency domains. A square shown in FIG.11B 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-subframeconfiglist, csi-rs-configZPid, qcl-csi-rs-configNZPid), and / or other radio resource parameters.

[0163] The three beams illustrated in FIG.11B may be configured for a UE in a UE-specific configuration. Three beams are illustrated in FIG.11B (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.

[0164] CSI-RSs such as those illustrated in FIG.11B (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).Docket No.: 24-1227PCT 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.

[0165] 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 measurement report 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 (RI).

[0166] 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.

[0167] 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 sweepDocket No.: 24-1227PCT 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.

[0168] 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).

[0169] 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.

[0170] 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 RRC_IDLE state and / or an RRC_INACTIVE 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.Docket No.: 24-1227PCT

[0171] 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 11311, a Msg 21312, a Msg 31313, and a Msg 41314. The Msg 11311 may include and / or be referred to as a preamble (or a random access preamble). The Msg 21312 may include and / or be referred to as a random access response (RAR).

[0172] 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 RRC_INACTIVE state). The UE may determine, based on the one or more RACH parameters, a time-frequency resource and / or an uplink transmit power for transmission of the Msg 11311 and / or the Msg 31313. Based on the one or more RACH parameters, the UE may determine a reception timing and a downlink channel for receiving the Msg 21312 and the Msg 41314.

[0173] 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 11311. 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-ConfigIndex). 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.

[0174] The one or more RACH parameters provided in the configuration message 1310 may be used to determine an uplink transmit power of Msg 11311 and / or Msg 31313. 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 11311 and the Msg 31313; 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 UEDocket No.: 24-1227PCT 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).

[0175] The Msg 11311 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.

[0176] 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 31313. 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 11311 based on the association. The Msg 11311 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-OccasionMskIndex and / or ra-OccasionList) may indicate an association between the PRACH occasions and the one or more reference signals.

[0177] 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 preambleDocket No.: 24-1227PCT 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).

[0178] The Msg 21312 received by the UE may include an RAR. In some scenarios, the Msg 21312 may include multiple RARs corresponding to multiple UEs. The Msg 21312 may be received after or in response to the transmitting of the Msg 11311. The Msg 21312 may be scheduled on the DL-SCH and indicated on a PDCCH using a random access RNTI (RA-RNTI). The Msg 21312 may indicate that the Msg 11311 was received by the base station. The Msg 21312 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 31313, 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 21312. The UE may determine 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 Type1-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:

[0179] RA-RNTI= 1 + s_id + 14 × t_id + 14 × 80 × f_id + 14 × 80 × 8 × ul_carrier_id, where s_id may be an index of a first OFDM symbol of the PRACH occasion (e.g., 0 ≤ s_id < 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).

[0180] The UE may transmit the Msg 31313 in response to a successful reception of the Msg 21312 (e.g., using resources identified in the Msg 21312). The Msg 31313 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 31313 and the Msg 41314) mayDocket No.: 24-1227PCT 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 31313 (e.g., a C-RNTI if assigned, a TC-RNTI included in the Msg 21312, and / or any other suitable identifier).

[0181] The Msg 41314 may be received after or in response to the transmitting of the Msg 31313. If a C-RNTI was included in the Msg 31313, 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 31313 (e.g., if the UE is in an RRC_IDLE state or not otherwise connected to the base station), Msg 41314 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 31313, the UE may determine that the contention resolution is successful and / or the UE may determine that the random access procedure is successfully completed.

[0182] 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 11311 and / or the Msg 31313) may remain on the selected carrier. The UE may switch an uplink carrier during the random access procedure (e.g., between the Msg 11311 and the Msg 31313) in one or more cases. For example, the UE may determine and / or switch an uplink carrier for the Msg 11311 and / or the Msg 31313 based on a channel clear assessment (e.g., a listen-before-talk).

[0183] 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 11321 and a Msg 21322. The Msg 11321 and the Msg 2 1322 may be analogous in some respects to the Msg 11311 and a Msg 21312 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 31313 and / or the Msg 41314.

[0184] 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 mayDocket No.: 24-1227PCT indicate or assign to the UE the preamble to be used for the Msg 11321. The UE may receive, from the base station via PDCCH and / or RRC, an indication of a preamble (e.g., ra-PreambleIndex).

[0185] 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., recoverySearchSpaceId). 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 11321 and reception of a corresponding Msg 21322. 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 preamble transmitted 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.

[0186] 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.

[0187] 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 31313 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 21312 (e.g., an RAR) illustrated in FIGS.13A and 13B and / or the Msg 41314 illustrated in FIG. 13A.

[0188] 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.

[0189] 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 theDocket No.: 24-1227PCT 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 FDM, 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.

[0190] 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-step random 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).

[0191] 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.

[0192] 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.

[0193] 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).

[0194] 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-Docket No.: 24-1227PCT 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 31313 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.

[0195] 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.

[0196] 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 inDocket No.: 24-1227PCT 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).

[0197] 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.

[0198] 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 purpose of 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.

[0199] 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).

[0200] 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 PDCCHDocket No.: 24-1227PCT 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).

[0201] 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 HARQ acknowledgements 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 (PUSCH). The UE may transmit the uplink control signaling via a PUCCH using one of several PUCCH formats.

[0202] 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 fourteenDocket No.: 24-1227PCT 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.

[0203] 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 first PUCCH 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”.

[0204] 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.

[0205] 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.1B, 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.Docket No.: 24-1227PCT

[0206] 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.

[0207] 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.

[0208] 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.

[0209] 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.

[0210] 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 / orDocket No.: 24-1227PCT beamforming. In other examples, the wireless device 1502 and / or the base station 1504 may have a single antenna.

[0211] 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.

[0212] 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 on- board 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.

[0213] 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 andDocket No.: 24-1227PCT 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.

[0214] 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 may be 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.

[0215] 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.

[0216] 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.

[0217] 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.

[0218] 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 configurationDocket No.: 24-1227PCT 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.

[0219] 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 be understood 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.

[0220] In an example, a base station may transmit one or more SSBs in a SSB burst. The base station may periodically repeat transmissions of the SSB burst. A SSB may be referred as a SS / PBCH block in the specification.

[0221] FIG.17 shows an example of SSB transmission of a cell by a base station.

[0222] In the example shown in FIG.17, a SCS of the cell is 15 kHz, and the cell is configured with a carrier frequency within a range of 3GHz<fc<=7GHz.

[0223] Also in the example of FIG.17, the maximum number of candidate SSBs in a SSB burst is 8 (Lmax=8).

[0224] In FIG.17, SSB#1 starts at symbol#2 of 70 symbols within 5 milliseconds (ms), SSB#2 starts at symbol#8, SSB#3 starts at symbol#16, SSB#4 starts at symbol#22, SSB#6 starts at symbol#36, and SSB#8 starts at symbol 50. The SSB#5 and SSB#7 are skipped or not transmitted in the SSB burst. The ssb-PositionsInBurst may indicate [11110101] for indicating transmission of SSBs#1-#4, SSB#6, and SSB#8, and skip or non-transmission of SSB#5 and SSB#7.

[0225] The SSB burst is transmitted in the first half (not the second half as shown in FIG.17) of a radio frame of 10 ms. As shown in FIG.17, the base station may repeat the SSB burst in every 20 ms. A periodicity of the SSB transmission in this disclosure may refer a periodicity of the SSB burst. In oneDocket No.: 24-1227PCT example, the SSB burst may be indicated / configured by ssb-periodicityServingCell or set to 5ms as a default.

[0226] In an example, the SSB / SSB burst (i.e., each SSB of the SSB burst) may be transmitted in a periodicity.

[0227] In the example shown in FIG.17, a default periodicity of a SSB burst is 20 ms, e.g., before a wireless device receives a SIB1 message for an initial access of the cell.

[0228] 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.

[0229] The base station does not transmit the SSB burst in the remaining 15 ms of the each 20 ms.

[0230] In an example, a base station may transmit RRC messages (e.g., containing SIB1 and / or ServingCellConfigCommon IE) indicating cell specific configuration parameters of SSB transmission of a serving cell (e.g., a PCell or a SCell).

[0231] The cell specific configuration parameters may comprise a value for a transmission periodicity (ssb-PeriodicityServingCell) of a SSB burst, and locations of a number of SSBs (e.g., transmitted SSBs), of a plurality of candidate SSBs, comprised in the SSB burst. The plurality of candidate SSBs may be determined based on one or more configurations via e.g., MIB. For instance, in the example shown in FIG. 17, candidates illustrated as #1 to #8 may represent the plurality of candidate SSBs, and the base station transmits SSBs via #1, #2, #3, #4, #6 and #8 candidates and does not transmit SSBs via #5 and #7.

[0232] The cell specific configuration parameters may comprise position indication of a SSB in a SSB burst (e.g., ssb-PositionsInBurst). The position indication may comprise a first bitmap (e.g., groupPresence) and a second bitmap (e.g., inOneGroup). The first and second bitmaps indicate locations of a number of SSBs comprised in a SSB burst. The position indication may also comprise a third bitmap (e.g., inOneGroup) indicating locations of a number of SSBs comprised in a SSB burst. For instance, in the example shown in FIG.17, the third bitmap may indicate [1, 1, 1, 1, 0, 1, 0, 1] where each bit indicated by the third bitmap corresponds to each of the plurality of candidate SSBs in the SSB burst. When the first bitmap and the second bitmap is used, a first bit of the second bitmap may represent a SSB index wit 0, 8, and so on, where exact indexes are determined based on the first bitmap. For example, if a first bit of the first bitmap is 1 and the first bit of the second bitmap is 1, a SSB with 0 is transmitted. If a second bit of the first bitmap is and the first bit of the second bitmap is 1, a SSB with index 8 is transmitted. The first bitmap and the second bitmap may represent up to 64 SSB indexes.

[0233] In an example, an index of a SSB of the SSBs in a SSB burst may be determined based on the plurality of candidate SSBs and / or a location, corresponding to the SSB, in the first bitmap (or based on the first bitmap and the second bitmap). A candidate SSB may refer a candidate resource (e.g., time / frequency resources comprising PSS / PBCH / SSS in FIG.17) where a SSB may be transmitted. For example, aDocket No.: 24-1227PCT candidate SSB in #1 transmits an SSB. A candidate SSB in #5 does not transmit an SSB. For example, a first index of a first SSB transmission occurring in a slot 0 OFDM symbol 2-5 is 0, and a second index of a second SSB transmission occurring in the slot 0 OFDM symbol 9-12 is 1. The wireless device may determine a plurality of indexes for the plurality of candidate SSBs. In the example of FIG.17, an index = 4 or 6 for SSB will not be used or the base station does not transmit SSB with an index of 4 or 6 in each SSB burst for the cell. A maximum index in a SSB burst may be predetermined / predefined for a frequency band that the cell operates or may be determined based on a size of the third bitmap (or the combination of the first bitmap and the second bitmap).

[0234] In an example, a base station may transmit, for a cell, a Master Information Block (MIB) on a PBCH of a SSB, to indicate configuration parameters (for CORESET#0) for a wireless device monitoring PDCCH for receiving a SIB1 message. In an example, a SSB comprising the MIB indicating the configuration parameters for the CORESET#0 may be referred as a cell-defining SSB of the cell.

[0235] The base station may transmit a MIB message (i.e., a message comprising an MIB) with a transmission periodicity of 80 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.

[0236] In an example, a base station may transmit, for a cell, a Master Information Block (MIB) on a PBCH of a SSB without indicating configuration parameters for a CORESET#0 or without scheduling information for receiving a SIB1 for the cell. In an example, the SSB without configuration parameters for the CORESET#0 may be referred as a non-cell defining SSB.

[0237] In an example, the non-cell defining SSB may be transmitted via one or more non-channel raster of a frequency band or one or more channel rasters of the frequency band.

[0238] In an example, the cell defining SSB may be transmitted via one or more non-channel raster of a frequency band or one or more channel rasters of the frequency band.

[0239] In an example, a wireless device may receive one or more configuration parameters for the cell defining SSB via a SIB1, and one or more serving cell configuration common parameters (e.g., ServingCellConfigCommon, ServingCellConfigCommonSIB).

[0240] In an example, a wireless device may receive one or more configuration parameters for the non- cell defining SSB via a downlink bandwidth part for a cell (e.g., BWP-DownlinkDedicated) or via a RRC release for small data transmission (e.g., SuspendConfig).

[0241] In an example, when a wireless device detects an SSB, and the PBCH in the SSB indicates that there is no associated SIB1, the wireless device may be pointed to another frequency at which the wireless device can search for an SSB that is associated with an SIB1 as well as a frequency range in which theDocket No.: 24-1227PCT wireless device may assume that 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.

[0242] In an example, a base station may transmit a SIB1 message with a periodicity of 160 ms. Alternatively or additionally, the base station may transmit the same SIB1 message with variable transmission repetition periodicity within 160 ms.

[0243] The default transmission repetition periodicity of SIB1 is 20 ms.

[0244] The base station may determine an actual transmission repetition periodicity based on network implementation.

[0245] In an example, a base station may transmit SSBs over / via each serving cell (e.g., a PCell or an SCell) of multiple serving cells configured for a wireless device. In an example, a wireless device may be configured with a serving cell. A base station may transmit one or more SSB bursts, in different frequency resources, in each serving cell. For example, the base station may transmit a first set of SSBs on a first frequency resource of a serving cell. The first set of SSBs may be cell defining SSBs. In addition to the first set of SSBs, the base station may transmit a second set of SSBs on a second frequency resource of the serving cell. The second set of SSBs may be non-cell defining SSBs. A wireless device may receive either the first set of SSBs or the second set of SSBs for an active BWP of the serving cell. The wireless device may switch from receiving the first set of SSBs to receiving the second set of SSBs (or vice versa) based on a BWP switching between a first BWP and a second BWP of the serving cell. For example, the first BWP is an initial BWP of the cell. The second BWP may be a non-initial BWP of the cell.

[0246] If configured, the base station may periodically transmit one or more SSBs of the first set of SSBs. If configured, the base station may periodically transmit one or more SSBs of the second set of SSBs. In this disclosure, one or more SSBs and / or a SSB burst that will be periodically transmitted once configured / indicated may be referred as {always-on SSBs and / or always-on SSB burst}, {normal SSBs and / or normal SSB burst}, {non-on-demand SSBs and / or non-on-demand SSB burst}, {cell-defining / non- cell defining SSBs and / or cell-defining / non-cell defining SSB burst} or {(semi-)statically / permanently activated SSBs and / or (semi-)statically / permanently activated SSBs} or {SSBs of a cell or a SSB-burst of a cell}.

[0247] A base station may transmit cell defining SSBs or non-cell defining SSBs for a first cell of a plurality serving cells of a wireless device. The base station may skip transmission of any SSBs (either cell defining SSBs or non-cell defining SSBs) for a second cell of the plurality of cells of the wireless device. In the specification, the first cell may be referred as a cell, a normal cell, a cell with always-on SSBs, or a serving cell with SSBs. The second cell may be referred as a cell without SSB, an SSB-less cell, a serving cell without SSBs, a serving cell without on-demand SSBs, or a serving cell without cell defining / non-cell defining SSBs.Docket No.: 24-1227PCT

[0248] A wireless device may monitor a set of candidates for one or more downlink control channels in a Type0-PDCCH common search space set. For example, the Type0-PDCCH common search space set may be configured by at least one information element, e.g., a PDCCH-ConfigSIB1 in a MIB. For example, the Type0-PDCCH common search space set may be configured by one or more search space sets, e.g., a searchSpaceSIB1 in a PDCCH-ConfigCommon, or a searchSpaceZero in a PDCCH-ConfigCommon. For example, the Type0-PDCCH common search space set may be configured for a first format of a first downlink control information (DCI) scrambled by a first radio network temporary identifier, e.g., a system information-radio network temporary identifier (SI-RNTI).

[0249] A wireless device may monitor a set of candidates for the one or more downlink control channels in a Type1-PDCCH common search space set. For example, the Type1-PDCCH common search space set may be configured by one or more search space sets, e.g., a ra-searchSpace in the PDCCH- ConfigCommon. For example, the Type1-PDCCH common search space set may be configured for a second format of a second DCI scrambled by a second radio network temporary identifier, e.g., a random access-radio network temporary identifier (RA-RNTI), a temporary cell-radio network temporary identifier (TC-RNTI), C-RNTI, and / or an RNTI that generated by a wireless device, e.g., generated for a two-step RA procedure.

[0250] A wireless device may determine, for example during a cell search, that a first control resource set for a first common search space (e.g., Type0-PDCCH) is present. The first control resource set may comprise one or more resource blocks and one or more symbols. The wireless device may receive one or more RRC messages. The one or more RRC messages may comprise one or more parameters indicating one or more monitoring occasions of one or more downlink control channels. The wireless device may determine a number of consecutive resource blocks and a number of consecutive symbols for the first control resource set of the first common search space. One or more bits (e.g., four most significant bits) of at least one information element (e.g., PDCCH-ConfigSIB1) may indicate the number of consecutive resource blocks and the number of consecutive symbols. The wireless device may determine the one or more monitoring occasions of the one or more downlink control channels from one or more bits (e.g., a four least significant bits) of the at least one information element (e.g., PDCCH-ConfigSIB1). For example, the one or more monitoring occasions of the one or more downlink control channels associated with a first downlink reference signal (e.g., SSB or CSI-RS) may be determined based on one or more system frame numbers and one or more slot indexes of the first control resource set. The first downlink reference signal with a first index may overlap in time with the first frame number and the first slot index.

[0251] The wireless device may determine a first downlink channel among the one or more downlink control channels, based on a first downlink reference signal (e.g., SSB or CSI-RS). The first downlink channel may be a first downlink control channel, or a first system information block (e.g., SIB1). TheDocket No.: 24-1227PCT wireless device may determine that a demodulation reference signal antenna port associated with a reception of the first downlink channel is quasi co-located (QCL) with the first downlink reference signal. For example, the demodulation reference signal antenna port associated with the reception of the first downlink channel and the first downlink reference signal (e.g., the corresponding SS / PBCH block) may be quasi co- located with respect to at least one of the following: an average gain, QCL-TypeA, and / or QCL-TypeD.

[0252] A wireless device may receive, from a base station, one or more RRC messages comprising one or more random access parameters. The one or more RRC messages comprise a common (or generic) random access configuration message (e.g., RACH-ConfigCommon and / or RACH-ConfigGeneric) indicating at least one of: a total number of random access preambles (e.g., totalNumberOfRA-Preambles), one or more PRACH configuration indexes (e.g., prach-ConfigurationIndex), a number of PRACH occasions that may be multiplexed in frequency domain (FDMed) in a time instance (e.g., msg1-FDM), an offset of the lowest PRACH occasion in frequency domain with respect to a first resource block (e.g., msg1- FrequencyStart), a power ramping step for PRACH (e.g., powerRampingStep), a target power level at the network receiver side (e.g., preambleReceivedTargetPower), the maximum number of random access preamble transmissions that may be performed (e.g., preambleTransMax), a window length for a random access response (i.e., RAR, e.g., Msg2) (e.g., ra-ResponseWindow), a number of SSBs per random access channel (RACH) occasion (RO), and a number of contention-based preambles per SSB (e.g., ssb- perRACH-OccasionAndCB-PreamblesPerSSB). The total number of random access preambles may be a multiple of the number of SSBs per RACH occasion (RO). For example, the window length for RAR may be in number of slots. For example, a dedicated random access configuration message (e.g., RACH- ConfigDedicated) may comprise one or more RACH occasions (ROs) for contention-free random access (e.g., occasions), and one or more PRACH mask indexes for random access resource selection (e.g., ra- ssb-OccasionMaskIndex).

[0253] The one or more random access parameters (e.g., ssb-perRACH-OccasionAndCB- PreamblesPerSSB) may indicate a first number (e.g., ^) of one or more downlink reference signals (e.g., SS / PBCH blocks) that may be associated with a first PRACH occasion (RO). The one or more random access parameters (e.g., ssb-perRACH-OccasionAndCB-PreamblesPerSSB) may indicate a second number (e.g., ^) of the one or more random access preambles for the first downlink reference signal and for the first PRACH occasion. The one or more random access preambles may be contention based preambles. The first downlink reference signal may be a first SS / PBCH block. The first number (e.g., if^ < 1) indicates that the first SS / PBCH block may be mapped to at least one (e.g., 1 / ^) consecutivevalid PRACH occasion. The second number (e.g., ^) indicates that at least one preamble with consecutive indexes associated with the first SS / PBCH block may start from the first preamble index for the first valid PRACH occasion.Docket No.: 24-1227PCT

[0254] The one or more PRACH configuration indexes (e.g., prach-ConfigurationIndex), may indicate a preamble format, a periodicity for the one or more PRACH time resources, one or more PRACH subframe numbers, a number of PRACH slots within the one or more PRACH subframes, a PRACH starting symbol number, and / or a number of time domain PRACH occasions within the first PRACH slot.

[0255] The one or more random access parameters may further comprise an association period for mapping the one or more SS / PBCH blocks to the one or more PRACH occasions. The one or more SS / PBCH block indexes may be mapped to the one or more PRACH occasions based on an order. An example of the order may be as follows: an increasing order of the indexes of the at least one preamble in the first PRACH occasion; an increasing order of the indexes of the one or more frequency resources (e.g., for frequency multiplexed PRACH occasions); an increasing order of the indexes of the one or more time resources (e.g., for time multiplexed PRACH occasions) in the first PRACH slot; and / or an increasing order of the indexes for the PRACH slots.

[0256] In an example, the one or more random access parameters may indicate one or more Physical RACH (PRACH) occasions available for transmission of the Msg 1 transmission. The one or more PRACH occasions may be predefined. The one or more random access parameters may indicate one or more available sets of one or more PRACH occasions (e.g., prach-ConfigIndex). The one or more random access parameters may indicate an association between (a) one or more PRACH occasions and (b) one or more reference signals. The one or more random access 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 random access 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. The Msg1 transmission 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 wireless device may determine the preamble group based on a pathloss measurement and / or a size of the Msg 3 PUSCH. 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 wireless device 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. One or more random access (e.g., RACH) parameters (e.g., ra-ssb-OccasionMskIndex and / or ra-OccasionList) may indicate an association between the PRACH occasions and the one or more reference signals.Docket No.: 24-1227PCT

[0257] In an example, mapping between one or more SSBs and one or more random access occasions (e.g., PRACH occasions, ROs), the wireless device may determine SSB indexes based on the ssb- PositionsInBurst in SIB1 or in ServingCellConfigCommon or in SSB-MTC-AdditionalPCI or in LTM-SSB- Config. The wireless device may determine a set of valid ROs based on the one or more random access parameters and / or a TDD downlink / uplink configuration paraemters and / or SSB(s) transmission.

[0258] The wireless device may map a SSB index to a valid RO (e.g., between SSB indexes and the set of valid ROs) within a RACH occasion period as follows.

[0259] A) First, in increasing order of preamble indexes within a single PRACH occasion

[0260] B) Second, in increasing order of frequency resource indexes for frequency multiplexed PRACH occasion

[0261] C) Third, in increasing order of time resource indexes for time multiplexed PRACH occasions within a PRACH slot

[0262] D) Fourth, in increasing order of indexes for PRACH slots

[0263]

[0264] An association period, starting from frame 0, for mapping SSB indexes to PRACH occasions (the set of valid ROs) is the smallest integer number in the set determined by the PRACH configuration period according Table 8.1-1 such that ^^^^^^SSB indexes are mapped at least once to the PRACH occasions (ROs) within the associationwhere a wireless device obtains ^^^^^^from the value of ssb- PositionsInBurst in SIB1 or in ServingCellConfigCommon or in SSB-MTC-AdditionalPCI or in LTM-SSB- Config. If after an integer number of SS / PBCH block indexes to PRACH occasions mapping cycles within the association period there is a set of PRACH occasions or PRACH preambles that are not mapped to ^^^^^^SS / PBCH block indexes, no SS / PBCH block indexes are mapped to the set of PRACH occasions or PRACH preambles. An association pattern period may include one or more association periods and is determined so that a pattern between PRACH occasions and SS / PBCH block indexes repeats at most every 160 msec. PRACH occasions not associated with SS / PBCH block indexes after an integer number of association periods, if any, are not used for PRACH transmissions. For example, if the one or more random access parameters indicate a mapping ratio or a number of ROs mapped to a SSB index (e.g., ssb- perRACH-OccasionAndCB-PreamblesPerSSB) as oneEight, one SSB index may be mapped to 8 ROs. If there are four SSB indexes, totally 32 valid ROs should be comprised in an association period. TheDocket No.: 24-1227PCT association period may be a smallest integer in the Table 8.1-1 based on the PRACH configuration period such that the smallest integer provides 32 valid ROs within the association period.

[0265] The ssb-perRACH-OccasionAndCB-PreamblesPerSSB may indicate a number of SSBs per RACH occasion (e.g., RO). Value oneEight corresponds to one SSB associated with 8 RACH occasions (ROs), value oneFourth corresponds to one SSB associated with 4 RACH occasions and so on. Further, a value in each number of SSBs per RO mapping, a number of ROs assigned for a contention based random access may be indicated (e.g., 4 ROs out of 8 ROs for oneEight, etc).

[0266] The wireless device may be configured with the one or more random access parameters for a BWP of an uplink carrier of a serving cell. Alternatively or additionally, the wireless device may be configured with one or more sets of the one or more random access parameters for one or more BWPs of the serving cell. Alternatively or additionally, the wireless device may be configured with one or more sets of the one or more random access parameters for one or more uplink carriers of the serving cell.

[0267] The wireless device may determine a set of PRACH occasions (ROs) based on the one or more random access parameters. The wireless device may determine the set of ROs as valid based on one or more conditions.

[0268] In an example, if the cell operates in a FDD band or a paired spectrum, the wireless device may determine the RO as valid.

[0269] In an example, if an uplink carrier of the serving cell is a supplementary uplink carrier (SUL carrier), the wireless device may determine the RO as valid.

[0270] In an example, if the serving cell operates in an unpaired spectrum, the uplink carrier is a normal uplink carrier (i.e., not an SUL carrier), and the wireless device is configured with one or more cell-specific TDD configurations (e.g., a tdd-UL-DL-ConfigurationCommon),

[0271] the wireless device may determine the RO in a PRACH slot as valid in response to: (1) the RO is within UL symbols by the one or more cell-specific TDD configurations,

[0272] or (2) the RO not preceding a SSB in the PRACH slot and starting at least Ngap symbols after the last downlink symbol indicated by the one or more cell-specific TDD configurations and at least the Ngap symbols after the last SSB block symbol. For example, the Ngap may be predetermined based on a subcarrier spacing of the uplink carrier of the serving cell. For example, the number of the Ngap symbols (or Ngap) is 2 for 15 kHz, 30 kHz, 60 kHz, or 120 kHz. In the example, the wireless device may determine the last SSB block symbol based on one or more candidate SSBs of the serving cell, where the wireless device expects that the base station may transmit a SSB in each of the candidate SSBs. The wireless device may determine the one or more candidate SSBs based on a ssb-PositionsInBurst in SIB1 or in ServingCellConfigCommon for the serving cell.Docket No.: 24-1227PCT

[0273] In an example, if the serving cell operates in an unpaired spectrum, the uplink carrier is a normal uplink carrier (i.e., not an SUL carrier), and the wireless device is not configured with one or more cell- specific TDD configurations (e.g., a tdd-UL-DL-ConfigurationCommon),

[0274] the wireless device may determine the RO in a PRACH slot as valid in response to:

[0275] the RO not preceding a SSB in the PRACH slot and starting at least the Ngap symbols after the last downlink symbol indicated by the one or more cell-specific TDD configurations and at least the Ngap symbols afterthe last SSB block symbol.

[0276] In an example, a value of Ngap may be 0 for a certain preamble format (e.g., preamble format B4).

[0277] FIG.18 illustrates an example of an unpaired spectrum according to an aspect of an embodiment of the present disclosure. FIG.18 shows a set of ROs for an uplink carrier of a cell and a set of candidate SSBs via the cell. The set of ROs may be configured for the uplink carrier of the cell, and the set of candidate SSBs may be configured for downlink carrier of the cell.

[0278] A wireless device may be configured with one or more random access parameters e.g., via RACH- ConfigCommon and / or RACH-ConfigGeneric for the uplink carrier of the cell. The wireless device may determine the set of ROs based on the one or more random access parameters as described above.

[0279] The one or more random access parameters may indicate a PRACH configuration index (e.g., prach-ConfigurationIndex). The wireless device may determine a preamble format, one or more slots where RO may be mapped, one or more subframes where RO may be mapped, a starting symbol in a slot of the one or more slots, and / or a number of time domain ROs in the slot (e.g., a PRACH slot). A periodicity of the set of ROs may be a frame (e.g., 10msec). The wireless device may determine periodic ROs based on the PRACH configuration index.

[0280] For a Type-2 random access procedure, a wireless device may transmit a PUSCH, after transmitting a PRACH. The PUSCH may be referred as a PUSCH for Type-2 random access procedure or a PUSCH-Msg 1 (e.g.,a. PUSCH with Msg 1). The PUSCH transmission may be after the PRACH transmission by at least N symbols (e.g., N = 2 for SCS = 15 kHz, 30 kHz or N = 4 for SCS = 60 kHz, etc.). A wireless device may not transmit a PUSCH in a PUSCH occasion (PO) if the PO associated with a DMRS resource is not mapped to a preamble of a valid RO or if the associated PRACH preamble is not transmitted. The wireless device may transmit a PRACH preamble in a valid RO if the PRACH preamble is not mapped to the valid PO.

[0281] A mapping between one or multiple PRACH preambles and a PUSCH occasion associated with a DMRS resource is per PUSCH configuration provided by MsgA-PUSCH-Resource.

[0282] A wireless device may determine time resources and frequency resources for PUSCH occasions in an active UL BWP from msgA-PUSCH-Config or eparateMsgA-PUSCH-Config for the active UL BWP. If the active UL BWP is not the initial UL BWP and msgA-PUSCH-Config or separateMsgA-PUSCH-Config isDocket No.: 24-1227PCT not provided for the active UL BWP, the wireless device may use the msgA-PUSCH-Config or separateMsgA-PUSCH-Config provided for the initial UL BWP.

[0283] If a wireless device does not have dedicated RRC configuration, or has an initial UL BWP as an active UL BWP, or is not provided startSymbolAndLengthMsgA-PO,

[0284] msgA-PUSCH-timeDomainAllocation provides a SLIV and a PUSCH mapping type for a PUSCH transmission by indicating (1) one of the first maxNrofUL-Allocations values from PUSCH- TimeDomainResourceAllocationList, if PUSCHTimeDomainResourceAllocationList is provided in PUSCH- ConfigCommon, or (2) one of the entries from one or more TDRA tables, if PUSCHTimeDomainResourceAllocationList is not provided in PUSCH-ConfigCommon.

[0285] If the wireless device may have dedicated RRC configuration, or has the initial UL BWP as the active UL BWP, or may be provided startSymbolAndLengthMsgA-PO, the wireless device is provided a SLIV by startSymbolAndLengthMsgA-PO, and a PUSCH mapping type by mappingTypeMsgA-PUSCH for a PUSCH transmission

[0286] For mapping one or multiple preambles of a PRACH slot to a PUSCH occasion associated with a DMRS resource, a wireless device may determine a first slot for a first PUSCH occasion in an active UL BWP from msgA-PUSCH-TimeDomainOffset that provides an offset, in number of slots in the active UL BWP, relative to the start of a PUSCH slot including the start of each PRACH slot. The wireless device may not expect to have a PRACH preamble transmission and a PUSCH transmission with a msgA in a PRACH slot or in a PUSCH slot, or to have overlapping msgA PUSCH occasions for a MsgA PUSCH configuration. The wireless device may expect that a first PUSCH occasion in each slot has a same SLIV for a PUSCH transmission that is provided by startSymbolAndLengthMsgA-PO or msgA-PUSCH-timeDomainAllocation. Consecutive PUSCH occasions within each slot are separated by guardPeriodMsgA PUSCH symbols and have same duration. A number ^^ of time domain PUSCH occasions in each slot is provided by nrofMsgA- PO-perSlot and a number ^^ of consecutive slots that include PUSCH occasions is provided by nrofSlotsMsgA-PUSCH. A wireless device is provided a DMRS configuration for a PUSCH transmission in a PUSCH occasion in an active UL BWP by msgA-DMRS-Config.

[0287] A wireless device may be provided with an MCS for data information in a PUSCH transmission for a PUSCH occasion by msgA-MCS.

[0288] A PUSCH occasion for PUSCH transmission may be defined by a frequency resource and a time resource, and is associated with DMRS resources. The DMRS resources are provided by msgA-DMRS- Config. Each consecutive number of ^preamblepreamble indexes from valid PRACH occasions in a PRACH slot

[0289] first, in increasing order of preamble indexes within a single PRACH occasionDocket No.: 24-1227PCT

[0290] second in increasing order of frequency resource indexes for frequency multiplexed PRACH occasions

[0291] third, in increasing order of time resource indexes for time multiplexed PRACH occasions within a PRACH slot

[0292] are mapped to a valid PUSCH occasion and the associated DMRS resource

[0293] first, in increasing order of frequency resource indexes ^id for frequency multiplexed PUSCH occasions

[0294] second, in increasing order of DMRS resource indexes within a PUSCH occasion, where a DMRS resource index ^^^^id is determined first in an ascending order of a DMRS port index and second in an ascending order of a DMRS sequence index

[0295] third, in increasing order of time resource indexes ^id for time multiplexed PUSCH occasions within a PUSCH slot

[0296] fourth, in increasing order of indexes for ^^ PUSCH slots

[0297] In the example, where ^preamble = ^^^^(^preamble⁄^PUSCH), ^preamble is a total number of valid PRACH occasions per association patt ernperiod multiplied by the number of preambles per valid PRACH occasion provided by rach-ConfigCommonTwoStepRA, and ^PUSCHis a total number of valid PUSCH occasions per PUSCH configuration per association pattern period multiplied by the number of DMRS resource indexes per valid PUSCH occasion provided by msgA-DMRS-Config.

[0298] A PUSCH occasion is valid if it does not overlap in time and frequency with any valid PRACH occasion associated with either a Type-1 random access procedure or a Type-2 random access procedure. Additionally, for unpaired spectrum and for SSBs with indexes provided by ssb-PositionsInBurst in SIB1 or by ServingCellConfigCommon if a wireless device is not provided tdd-UL-DL-ConfigurationCommon, a PUSCH occasion is valid if the PUSCH occasion does not precede a SSB in the PUSCH slot, and starts at least ^gap symbols after a last SSB symbol, where ^gap is determined based on a subcarrier spacing.

[0299] if a wireless device is provided tdd-UL-DL-ConfigurationCommon, a PUSCH occasion is valid if the PUSCH occasion is within UL symbols, or does not precede a SSB in the PUSCH slot, and starts at least ^gap symbols after a last downlink symbol and at least ^gap symbols after a last SSB symbol, where ^gap is determined based on a subcarrier spacing.

[0300] FIG.18 illustrates 8 ROs where two ROs in each time occasion are FDM-ed. Two ROs in a first time occasion is referred with an index #1, and last two ROs in a last time occasion is referred with an index #4. In the example, the cell may have up to 8 possible SSB locations in a SSB burst. Based on a ssb- PositionsInBurst of the cell, the wireless device may determine that a first SSB in a slot #1, and a second SSB in a slot #2, and a third SSB in a slot #3 may be transmitted by a base station. The first SSB, the second SSB and the third SSB may be considered as a set of candidate SSBs. The wireless device mayDocket No.: 24-1227PCT determine the set of candidate SSBs will be periodically transmitted based on a periodicity of the SSB burst of the cell. The wireless device may determine other possible SSB locations as non-candidate SSBs and may not expect to receive a SSB on such resources. For example, the ssb-PositionsInBurst may indicate 1 for an SSB index = 0, 0 for an SSB index = 1, 0 for an SSB index = 2, 1 for an SSB index = 3, 1 for an SSB index = 4, and 0s for SSB index = 5 and 6.

[0301] The wireless device determines two ROs with a time resource #1 as valid as a RO of the two ROs does not precede a candidate SSB, of the set of candidate SSBs, in the slot #1. In the example, a PRACH slot may refer a slot where a RO is configured / indicated. The wireless device determines a second RO in a time resource #2 as invalid in response to the second RO preceding the second SSB in the slot #2. The wireless device determines a third RO in a time resource #3 as invalid in response to a gap (e.g., Gap2) from a last SSB (e.g., the third SSB) to the third RO being less than symbols (e.g., X symbols). The wireless device may determine a fourth RO in a time resource #4 as valid in response to the fourth RO not preceding a candidate SSB, of the set of candidate SSBs, in the slot #4.

[0302] The wireless device may determine the one or more valid ROs of the set of ROs of the uplink carrier of the cell. The wireless device may determine an association or a mapping between the set of candidate SSBs and / or SSB indexes of the set of candidate SSBs and the one or more valid ROs based on the order as described in the above.

[0303] In an example, a wireless device may determine a (symbol) type, for a symbol of a slot for a cell, from downlink, uplink or flexible. The wireless device may be configured with one or more TDD DL / UL configuration parameters such as a cell-specific parameter of tdd-UL-DL-ConfigurationCommon or a UE- specific parameter of tdd-UL-DL-ConfigurationDedicated. The tdd-UL-DL-ConfigurationCommon may indicate a set of symbols within 20msec (e.g., 2 frames) or a set of symbols in a periodicity P that is dividable by 20msec (e.g., 5msec, 10msec). One or more patterns, to determine (symbol) types in a set of symbols in the periodicity P, indicated by the tdd-UL-DL-ConfigurationCommon may be applied starting from a first symbol every 20 / P in an even frame. When the tdd-UL-DL-ConfigurationCommon indicates two patterns with a first periodicity P1 and a second periodicity P2, the periodicity P may be determined based on a sum of the first periodicity and the second periodicity (e.g., P = P1 + P2). The UE-specific parameter of the of tdd-UL-DL-ConfigurationDedicated may indicate one or more symbols’ types as downlink or uplink among flexible symbols indicated by the cell-specific parameter of the of tdd-UL-DL-ConfigurationCommon. The UE-specific parameter of the of tdd-UL-DL-ConfigurationDedicated may indicate one or more symbols’ types as downlink if the one or more symbols are indicated as downlink by the cell-specific parameter of the of tdd-UL-DL-ConfigurationCommon. The UE-specific parameter of the of tdd-UL-DL- ConfigurationDedicated may indicate one or more symbols’ type as uplink if the one or more symbols are indicated as uplink by the cell-specific parameter of the of tdd-UL-DL-ConfigurationCommon.Docket No.: 24-1227PCT

[0304] In an example, the wireless device may consider or may determine one or more symbols of a slot indicated as downlink by the by tdd-UL-DL-ConfigurationCommon or tdd-UL-DL-ConfigurationDedicated to be available for receptions downlink signals / channels (e.g., PDCCH, PDSCH, CSI-RS, SSB, and / or like). The wireless device may consider or determine one or more second symbols of a slot indicated as uplink by by tdd-UL-DL-ConfigurationCommon or tdd-UL-DL-ConfigurationDedicated to be available for transmissions of uplink signals / channels (e.g., PRACH, PUCCH, PUSCH, SRS and / or the like).

[0305] In an example, the wireless device may be configured to monitor PDCCH for a DCI format 2_0 for determining slot formats (e.g., types) for one or more symbols in a slot that are indicated as flexible by tdd- UL-DL-ConfigurationCommon or tdd-UL-DL-ConfigurationDedicated, or all symbols in the slot if tdd-UL-DL- ConfigurationCommon or tdd-UL-DL-ConfigurationDedicated is not provided / configured.

[0306] In the example, when the wireless device is not configured to monitor the PDCCH for the DCI format 2_0 for the one or more symbols that are flexible symbol(s),

[0307] the wireless device may receive PDSCH or CSI-RS in the set of symbols of the slot, if the wireless device receives a corresponding indication (e.g., downlink scheduling or aperiodic CSI request) by a DCI format, or,

[0308] the wireless device may transmit PUSCH, PUCCH, PRACH or SRS in the set of symbols of the slot, if the wireless device receives a corresponding indication (e.g., an UL grant, a PDCCH order) by a DCI format, a RAR UL grant, a fallbackRAR UL grant or a successRAR.

[0309] In the example, when the wireless device is configured by higher layers to receive a PDCCH, a CSI-RS or a DL-PRS in a set of symbols in a slot, the wireless device may receive the PDCCH, the CSI-RS or the DL PRS in the set of symbols of the slot,

[0310] unless the wireless device detects a DCI format that indicates to the wireless device to transmit a PUSCH, a PUCCH or a PRACH or a SRS in at least one symbol of the set of symbols in the slot.

[0311] Otherwise, the wireless device may not receive the PDCCH, or the PDSCH or the CSI_RS or the DL PRS in the set of symbols of the slot.

[0312] For a set of symbols of a slot that are indicated to the wireless device as uplink by the tdd-UL-DL- ConfigurationCommon, or the tdd-UL-DL-ConfigurationDedicated, the wireless device may not receive PDCCH, PDSCH, or CSI-RS when the PDCCH, PDSCH, or CSI-RS overlaps, even partially, with the set of symbols of the slot.

[0313] For a set of symbols of a slot that are indicated to the wireless device as downlink by the tdd-UL- DL-ConfigurationCommon, or the tdd-ULDL-ConfigurationDedicated, the wireless device may not transmit PUSCH, PUCCH, PRACH, or SRS when the PUSCH, PUCCH, PRACH, or SRS overlaps, even partially, with the set of symbols of the slot.Docket No.: 24-1227PCT

[0314] For a set of symbols of a slot that are indicated to the wireless device as flexible by the tdd-UL-DL- ConfigurationCommon, and the tdd-ULDL-ConfigurationDedicated if provided, the wireless device may not expect to receive both dedicated higher layer parameters configuring transmission from the wireless device in the set of symbols of the slot and dedicated higher layer parameters configuring reception by the wireless device in the set of symbols of the slot.

[0315] For operation on a single carrier in unpaired spectrum, for a set of symbols of a slot indicated to a UE for reception of SSBs configured / indicate by ssb-PositionsInBurst in SIB1 or by ssb-PositionsInBurst in ServingCellConfigCommon or, if the wireless device is not provided dl-OrJointTCI-StateList, by ssb- PositionsInBurst in SSB-MTCAdditionalPCI associated to physical cell ID with active TCI states for PDCCH or PDSCH, or for a set of symbols of a slot corresponding to SSBs configured for L1 beam measurement / reporting (e.g., for L1 / L2 layer mobility, LTM mobility),

[0316] the wireless device may not transmit PUSCH, PUCCH, PRACH in the slot. If a transmission would overlap with any symbol from the set of symbols and the wireless device may not transmit SRS in the set of symbols of the slot. The wireless device may not expect the set of symbols of the slot to be indicated as uplink by the tdd-UL-DLConfigurationCommon, or tdd-UL-DL-ConfigurationDedicated, when provided to the wireless device.

[0317] If a wireless device is configured with multiple serving cells and is provided with directionalCollisionHandling = 'enabled' for a set of serving cell(s) among the multiple serving cells, and indicates support of half-DuplexTDD-CA-SameSCS capability, and is not configured to monitor PDCCH for detection of DCI format 2_0 on any of the multiple serving cells,

[0318] for a set of symbols of a slot that are indicated to the wireless device for reception of SSBs in a first cell of the multiple serving cells indicated by / based on ssb-PositionsInBurst in SystemInformationBlockType1 or by ssb-PositionsInBurst in ServingCellConfigCommon of the first cell or, if the wireless device is not provided dl-OrJointTCI-StateList, by ssb-PositionsInBurst in SSBMTCAdditionalPCI associated to physical cell ID with active TCI states for PDCCH or PDSCH, or for a set of symbols of a slot corresponding to SSBs configured for L1 beam measurement / reporting, the wireless device may not transmit PUSCH, PUCCH, or PRACH in the slot if a transmission would overlap with any symbol from the set of symbols, and

[0319] the wireless device may not transmit SRS in the set of symbols of the slot in any of the multiple serving cells if the wireless device is not capable of simultaneous transmission and reception as indicated by simultaneousRxTxInterBandCA among the multiple serving cells, and any one of the cells corresponding to the same band as the first cell, irrespective of any capability indicated by simultaneousRxTxInterBandCA.Docket No.: 24-1227PCT

[0320] In an example, for a set of symbols of a slot comprising a valid PRACH occasion (RO) in the slot and Ngap symbols before the valid RO, the wireless device may not receive a PDCCH, a PDSCH, and / or CSI-RS in the slot if a reception of the PDCCH, the PDSCH and / or the CSI-RS would overlap with any symbol from the set of symbols. The wireless device may not consider / expect that the set of symbols of the slot to be indicated as downlink by the tdd-UL-DL-ConfigurationCommon or tdd-UL-DL- ConfigurationDedicated (if configured).

[0321] In an example, a base station may transmit SSBs over / via each serving cell (e.g., a PCell or an SCell) of multiple serving cells configured for a wireless device. In an example, a wireless device may be configured with a serving cell. A base station may transmit one or more SSB bursts, in different frequency resources, in the serving cell. For example, the base station may transmit a first set of SSBs (e.g., a first periodic SSB burst) on a first frequency resource of the serving cell. In the example, the first set of SSBs may be cell defining SSBs (e.g., cell defining SSB bursts). The base station may transmit a second set of SSBs (e.g., a second periodic SSB burst) on a second frequency resource of the serving cell. In the example, the second set of SSBs may be non-cell defining SSBs (e.g., non-cell defining SSBs). The wireless device may receive either the first set of SSBs or the second set of SSBs for an active BWP of the serving cell. A BWP of the serving cell may comprise either the first set of SSBs (e.g., cell defining SSBs) or the second set of SSBs (e.g., non-cell defining SSBs).

[0322] The wireless device may switch receiving from the first set of SSBs to the second set of SSBs (or vice versa) based on a BWP switching between a first BWP and a second BWP of the serving cell. For example, the first BWP is an initial BWP of the cell. The second BWP may be a non-initial BWP of the cell. The wireless device may monitor / measure / receive the first set of SSBs or the second set of SSBs based on an active BWP of the serving cell.

[0323] If configured, the base station may periodically transmit one or more SSBs of the first set of SSBs. If configured, the base station may periodically transmit one or more SSBs of the second set of SSBs. In the specification, one or more SSBs and / or a SSB burst that will be periodically transmitted once configured / indicated may be referred as {always-on SSBs and / or always-on SSB burst}, {normal SSBs and / or normal SSB burst}, {non-on-demand SSBs and / or non-on-demand SSB burst}, {cell-defining / non- cell defining SSBs and / or cell-defining / non-cell defining SSB burst} or {(semi-)statically / permanently activated SSBs and / or (semi-)statically / permanently activated SSBs} or {SSBs of a cell or a SSB-burst of a cell} or {periodic SSBs and / or a periodic SSB burst}.

[0324] A base station may transmit cell defining SSBs and / or non-cell defining SSBs for a first cell of a plurality serving cells of a wireless device. The base station may skip transmission of any SSBs (either cell defining SSBs or non-cell defining SSBs) for a second cell of the plurality of cells of the wireless device. In the specification, the first cell may be referred as a (serving) cell or a normal (serving)cell or a (serving) cellDocket No.: 24-1227PCT with always-on SSBs, or a (serving) cell with SSBs or a SSB cell. The second cell may be referred as a (serving) cell without SSB, an SSB-less (serving) cell, a serving cell with no SSBs, a serving cell with on- demand SSBs, or a serving cell without cell defining / non-cell defining SSBs.

[0325] In an example, a base station may transmit on-demand SSBs via / 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 or by RRC configurations or by transmitting a DCI indicating activation / deactivation). The base station may activate transmission of the on-demand SSBs and / or deactivate transmission of the on-demand SSBs. The base station may transmit the on-demand SSBs when the base station activates the transmission of the on-demand SSBs. The base station may not transmit the on-demand SSBs when the base station deactivates the transmission of the on-demand SSBs. The base station may transmit the on-demand SSBs, when activated, in addition to cell-defining SSBs or non-cell defining SSBs of the serving cell. The base station may transmit the on-demand SSBs for the serving cell that is an SSB-less cell (e.g., no cell-defining SSBs or non-cell defining SSBs are transmitted over / via the serving cell).

[0326] 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 / trigger may be referred to as on-demand SSBs. The SSBs may be activated / deactivated may be referred as on-demand SSBs or semi-persistent SSBs or temporary SSBs. In the specification, one or more SSBs and / or a SSB burst that will be transmitted / stopped based on one or more triggers via RRC / MAC-CE / DCI may be referred as {on-demand SSBs and / or on-demand SSB burst}, {non-legacy SSBs and / or non-legacy SSB burst}, {non-periodic cell-defining / non-cell defining SSBs and / or non-periodic cell-defining / non-cell defining SSB burst} or {semi-persistent SSBs and / or semi-persistent SSBs} or {additional SSBs of a cell or additional SSB-burst of a cell} or {aperiodic SSBs and / or aperiodic SSB burst}.

[0327] FIG.19 shows examples of a variety of SSB transmissions.

[0328] In an example, a base station may configure a serving cell (e.g., a PCell or a SCell, Cell 1 in FIG. 19) with (always-on / periodic) SSBs, in which case, the base station keeps transmitting the SSBs with periodicity (e.g., ssb-PeriodicityServingCell) based on configuration parameters of the SSBs.

[0329] 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.17.

[0330] In an example, the always-on SSBs may be present / configured on a PCell, and optionally be present / configured on a SCell. A wireless device may consider the always-on SSBs (or normal SSBs or cell-defining SSBs) being available to identify one or more candidate cells to camp-on duringDocket No.: 24-1227PCT RRC_idle / inactive state. The wireless device may consider a primary cell (PCell) transmits periodically cell defining SSBs (CD-SSBs). For a secondary cell (SCell), the wireless device may not assume that CD-SSBs are always present. Based on configuration, the secondary cell may be configured with one set of CD- SSBs. The secondary cell may be configured with one set of non-cell defining SSBs (NCD-SSBs). The secondary cell may be configured with one or more CD-SSBs and / or one or more NCD-SSBs. The secondary cell may be configured with one or more on-demand SSBs (OD-SSBs). The secondary cell may be configured with one or more CD-SSBs and one or more OD-SSBs. The secondary cell may be configured with one or more NCD-SSBs and one or more OD-SSBs. In the example, based on implementation, options available to the secondary cell may be extended to the primary cell without loss of generality.

[0331] The wireless device may obtain time and / or frequency synchronization (and / or beam alignment) with the serving cell based on SSBs (of OD-SSBs, CD-SSBs or NCD-SSBs or any combinations thereof).

[0332] As shown in FIG.19, a base station may configure a serving cell (e.g., a SCell, Cell 2 in FIG.19) 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.19) for obtaining time and / or frequency synchronization with this serving cell. For example, the wireless device may determine a reference cell for an SSB-less serving cell (e.g., Cell 1 in FIG.19) based on one or more configuration parameters. For example, the one or more configuration parameters for a frequency information of downlink (e.g., FrequencyInfoDL) may comprise a frequency location of CD-SSBs (e.g., absoluteFrequencySSB) when a cell comprises CD-SSBs. For the SSB-less serving cell, the frequency location of CD-SSBs may be absent (e.g., absoluteFrequencySSB is absent in FrequencyInfoDL). The one or more configuration parameters may comprise a cell index of the reference cell (e.g., referenceCell) when the cell does not comprise CD-SSBs (e.g., for the SSB-less serving cell). The cell may not comprise NCD- SSBs either. For the SSB-less serving cell, if the cell index of the reference cell is not present in the one or more configuration parameters, the wireless device may determine a reference cell among one or more cells operating in a same frequency band to the SSB-less serving cell.

[0333] The PCell / PSCell / SCell as a reference cell for an SSB-less scell may be indicated / configured via RRC messages (e.g., ServingCellConfigCommon IE and / or FrequencyInfoDL) of the serving cell.

[0334] The 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.

[0335] 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).Docket No.: 24-1227PCT

[0336] As shown in FIG.19, 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 parallelly 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).

[0337] There are multiple ways of providing the on-demand SSBs for this serving cell.

[0338] As a first way (as shown in FIG.19) 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.

[0339] 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.

[0340] In an example, the wireless device may trigger the transmission of the WUS based on channel measurement of discovery reference signals (DRSs) (if configured / transmitted) of the serving cell. The DRS may be a simplified SSB with only PSS and without SSS and PBCH, a simplified SSB with only SSS and without PSS and PBCH, or a CSI-RS, or a position RS, or a newly defined RS specifically for the on- demand SSB request.

[0341] 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).

[0342] 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.

[0343] 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.

[0344] As a second way (as shown in FIG.19) of providing the on-demand SSBs for a serving cell, the base station may trigger to transmit the on-demand SSB by activating the SCell. The base station may activate the SCell for a wireless device by transmitting a SCell activation / deactivation MAC CE.

[0345] Before the SCell is activated, the base station may skip (or may stop / refrain from) transmitting the on-demand SSBs.

[0346] After the SCell is activated, the base station may start transmitting the on-demand SSBs. The base station may determine when / whether to activate the SCell (together with the on-demand SSBDocket No.: 24-1227PCT transmissions) based on traffic load / request of wireless device(s) and / or requests from another base station via backhaul link.

[0347] 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.

[0348] Alternatively, the base station may activate / start / resume transmission of the on-demand SSBs by transmitting one or more MAC CEs (and / or RRC messages and / or DCIs) activating / starting / resuming the transmission of the on-demand SSBs to the wireless device. The base station may deactivate / stop / halt / pause transmission of the on-demand SSBs by transmitting one or more second MAC CEs (and / or RRC messages and / or DCIs) deactivating / stopping / halting / pausing the transmission of the on- demand SSBs to the wireless device. When on-demand SSBs are activated (or deactivated) via RRC messages, it may be deactivated (or activated) via one or more MAC CEs and / or RRC messages.

[0349] In an example, OD-SSBs are NCD-SSBs. In an example, a base station may activate or deactivate OD-SSBs without RRC reconfiguration of a cell. In an example, a wireless device may determine a status (e.g., active or inactive, started or stopped, activated or deactivated, transmitted or skipped, and / or the like) of OD-SSBs during RRC_Connected to a serving cell based on one or more MAC CEs (and / or DCIs) and / or RRC messages.

[0350] In an example, a base station may configure one or more tracking reference signal (TRS) for an activation of a secondary cell to a wireless device. In an example, the one or more TRS may comprise one or more CSI-RSs. The one or more TRS may be QCL-ed with one or more SSBs of a reference cell, for time / frequency tracking, for the secondary cell that is an SSB-less cell.

[0351] In an example, a SSB configurations for a SCell may be configured to a wireless device.

[0352] 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 CellGroupConfig IE) of cell group. The configuration parameters of a cell group may comprise SCell configuration parameters of a plurality of SCells (e.g., sCellToAddModList IE).

[0353] The SCell configuration parameters of each SCell may comprise a SCell index (sCellIndex), 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).

[0354] In an example, a smtc is associated with a periodicityAndOffset and a duration.

[0355] The smtc indicates SSB periodicity / offset / duration configuration of target cell for an NR SCell addition. The base station (or the network) sets the periodicityAndOffset to indicate the same periodicity as ssb-periodicityServingCell in sCellConfigCommon.Docket No.: 24-1227PCT

[0356] The smtc is based on the timing of the SpCell of associated cell group. In case of inter-RAT handover to NR, the timing reference is the NR PCell.

[0357] In case of intra-NR PCell change (standalone NR) or NR PSCell change (EN-DC), the timing reference is the target SpCell. If the smtc field is absent and absoluteFrequencySSB is included, the wireless device uses the SMTC in the measObjectNR having the same SSB frequency and subcarrier spacing, as configured before the reception of the RRC message.

[0358] If the SCell is an SSB-less SCell (i.e., the IE absoluteFrequencySSB in ServingCellConfigCommon is absent), the smtc field is absent.

[0359] In an example, for a cell measurement, a wireless device may set up the first SMTC in accordance with the received periodicityAndOffset parameter (comprising a value of Offset and a value of Periodicity) of SMTC.

[0360] The first subframe of each SMTC occasion occurs at a system frame number (SFN) and subframe of the NR SpCell meeting the following condition, wherein a structure of a frame and a structure of a subframe may be implemented based on example of FIG.7: SFN mod T = (FLOOR (Offset / 10)); if the Periodicity is larger than sf5: subframe = Offset mod 10; else: subframe = Offset or (Offset +5); with T = CEIL(Periodicity / 10).

[0361] In an example, the base station (or the network) may configure the wireless device in RRC_CONNECTED to derive RSRP, RSRQ and SINR measurement results per cell associated to NR measurement objects based on parameters configured in a measObject (e.g. maximum number of beams to be averaged and beam consolidation thresholds) and in a reportConfig (rsType to be measured, SS / PBCH block or CSI-RS). measObject and / or reportConfig is configured by the base station for the wireless device in one or more RRC messages.

[0362] The cell common parameters of the SCell may comprise downlink common configuration parameters (e.g., comprised in DownlinkConfigCommon IE), SSB burst configuration (ssb- PositionsInBurst), SSB periodicity (ssb-periodicityServingCell), SSB subcarrier spacing (ssbSubcarrrierSpacing) and SSB transmission power (ss-PBCH-BlockPower).

[0363] The downlink common configuration parameters of the SCell may comprise downlink frequency information (e.g., comprised in FrequencyInfoDL), 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.Docket No.: 24-1227PCT

[0364] 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.

[0365] The parameter is an ARFCN (absolute radio frequency channel number) value (AFRCN-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.

[0366] 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.

[0367] FIG.20 shows an example of on-demand SSB transmissions for a SCell.

[0368] 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.

[0369] 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.

[0370] 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.

[0371] In the example of FIG.20, 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.

[0372] 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., Scenario# 1 in FIG.21 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., Scenario# 2 in FIG.21 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 theDocket No.: 24-1227PCT signaling / command from the base station to trigger the on-demand SSB transmissions or transmits HARQ- ACK corresponding to the signaling / command.

[0373] In an example, the time instance B may be determined based on examples of FIG.22 which will be described later in this specification.

[0374] In the example of FIG.20, 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.

[0375] In the example of FIG.20, in a Case 2, the base station may transmit always-on SSBs (e.g., legacy SSBs, non-on-demand SSBs, non-on-demand SSB burst(s)) 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.

[0376] In the example of FIG.20, 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 or after / before the SCell is activated. In Case 1, the base station may not transmit non-on- demand SSBs on the SCell. When the base station transmits the on-demand SSBs via the SCell, the on- demand SSBs may be only SSBs on the SCell.

[0377] In the example of FIG.20, 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 are transmitted 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.

[0378] In the example of FIG.20, 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.

[0379] In an example, the on-demand SSB triggering / command / signaling may be a RRC message, a MAC CE and / or a DCI.

[0380] 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.

[0381] FIG.21 shows an example of on-demand SSB transmission scenarios for a SCell, e.g., based on examples of FIG.20. In the example of FIG.21, the legacy SSBs (e.g., always-on SSBs) are illustrated as a purpose of comparison with the on-demand SSBs.

[0382] In the example of FIG.21, 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 theDocket No.: 24-1227PCT 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.

[0383] 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.

[0384] 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.

[0385] In an example, the wireless device may determine whether a SCell is a known cell or a unknow cell.

[0386] 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.

[0387] 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.

[0388] 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.

[0389] In the example of FIG.21, 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 / before 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 or during the SCell is active.

[0390] 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.Docket No.: 24-1227PCT

[0391] 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.

[0392] 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.

[0393] In an example, different scenarios (e.g., Scenario 1 and Scenario 2 as shown in FIG.21) may be applied by the base station for different purposes.

[0394] 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.

[0395] 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.

[0396] Scenario 1 in FIG.21 illustrates a first scenario of on-demand SSB transmission by a base station for a secondary cell (SCell). For example, the base station may trigger or activate the on-demand SSBs of the SCell (e.g., OD-SSB trigger event via RRC, MAC-CE and / or DCI). The base station may transmit one or more on-demand SSB burst(s) of the on-demand SSB at least until the SCell becomes activated.

[0397] Scenario 2 in FIG.21 illustrates a second scenario of on-demand SSB transmission by a base station for a secondary cell (SCell). For example, the base station may trigger or activate the on-demand SSBs of the SCell at a time that the base station activates the SCell (e.g., via RRC, MAC-CE, DCI). The base station may transmit one or more on-demand SSB burst(s) of the on-demand SSBs at least until the SCell becomes activated and may continue transmission of the on-demand SSBs after the SCell being activated.

[0398] FIG.22 shows an example of on-demand SSB transmissions for a SCell, e.g., based on examples of FIG.20 and / or FIG.21. The base station and / or the wireless device may determine, based on multiple options (e.g., Option 1, Option 1A, 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.

[0399] In the example of FIG.22, 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.20), 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. The wireless device may determine / assume one or moreDocket No.: 24-1227PCT on-demand SSB bursts of the on-demand SSB after the time instance A in Option 1. The base station may continue the periodic transmission of the on-demand SSBs at least during the SCell being active.

[0400] In the example of FIG.22, in Option 1A, 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. The wireless device may determine / assume one or more on-demand SSB bursts of the on- demand SSB after the time instance A until the on-demand SSB being deactivated by the base station (or receiving the indication).

[0401] In the example of FIG.22, 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.

[0402] In the example of FIG.22, 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. In an example, a base station may transmit N (N>=1) times of on-demand SSB burst(s) based on Option 3 from a time instance A. The wireless device may consider / assume / determine the on-demand SSB burst(s) as active or being transmitted from the time instance A, and during N times of a periodicity of the on-demand SSB burst(s).

[0403] In the example of FIG.22, 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 Options 1A / 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). In an example, a base station may transmit on-demand SSB burst(s) with a first periodicity (P1 in FIG.22) from a time instance A to a time instance B. After the time instance B, the base station may transmit the on-demand SSB burst(s) with a second periodicity (P2 in FIG. 22). Option 4 illustrates this scenario. The wireless device may assume the first periodicity of the on- demand SSB burst(s) from the time instance A to the time instance B and the second periodicity of the on- demand SSB burst(s) after the time instance B.Docket No.: 24-1227PCT

[0404] Examples of FIG.20, FIG.21 and / or FIG.22 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.20 may be combined with Scenario 1 of FIG.21 (and / or with option 1A / 2 / 3 of FIG.22) to reduce both power consumption of the base station and / or the wireless device and / or SCell activation delay. Case 2 of FIG.20 may be combined with Scenario 2 of FIG.21 (and / or with option 1A / 2 / 3 of FIG.22) to improve L3 measurement accuracy of the wireless device and / or reduce power consumption of the wireless device, etc.

[0405] In an example, a SS / PBCH block index (or a SSB index) may be associated with a SSB of a serving cell and / or an on-demand SSB of the serving cell.

[0406] In an example, a wireless device may be configured with a list of TCI states (e.g., TCI-State) within / by a higher layer parameter PDSCH-Config to decode PDSCH according to a detected PDCCH with DCI intended for the wireless device and a given cell (e.g., a given serving cell, a given non- serving / candidate / target cell). A subset of the list of TCI states (e.g., tci-StatesPDCCH-ToAddList) may be configured for monitoring PDCCHs via the given cell. The wireless device may determine QCL relationship between one or more RS(s) on a TCI state associated with a CORESET and DM-RS port(s) of a PDCCH via the CORESET. The base station may configure up to maxNrofTCI-StatesPDCCH for the tci- StatesPDCCH-ToAddList.

[0407] A number of TCI states in the list may depend on a UE capability parameter maxNumberConfiguredTCIstatesPerCC. Each TCI state (e.g., TCI-State) may contain / comprise / include / indicate / have respective parameters for configuring a quasi co-location relationship / assumption / information between one or two downlink reference signals and DM-RS port(s) of a PDSCH, a DM-RS port of a PDCCH, or CSI-RS port(s) of a CSI-RS resource. An example configuration of a TCI state is shown in FIG.22.

[0408] The quasi co-location (QCL) relationship may be configured by a higher layer parameter qcl-Type1 for a first downlink reference signal of the one or more downlink reference signals. The quasi co-location relationship may be, optionally, configured by a higher layer parameter qcl-Type2 for a second downlink reference signal of the one or more downlink reference signals. When two downlink reference signals comprising a first downlink reference signal and a second downlink reference signal are indicated by a TCI state, QCL types of the two downlink reference signals may not be the same, regardless of whether the first downlink reference signal and the second downlink reference signal are the same or different. A quasi co- location type corresponding to a downlink reference signal of the one or more downlink reference signals may be given by a higher layer parameter qcl-Type in a higher layer parameter QCL-Info and may take oneDocket No.: 24-1227PCT of the following values: 'typeA': {Doppler shift, Doppler spread, average delay, delay spread}, 'typeB': {Doppler shift, Doppler spread}, 'typeC': {Doppler shift, average delay}, or 'typeD': {Spatial Rx parameter}.

[0409] In an example, a wireless device may be provided, for each BWP of a serving cell, a set ^^^of periodic CSI-RS resource configuration indexes by failureDetectionResourcesToAddModList and a set ^^^of periodic CSI-RS resource configuration indexes and / or SS / PBCH block indexes by candidateBeamRSList or candidateBeamRSListExt or candidateBeamRSSCellList for radio link quality measurements on the BWP of the serving cell. Instead of the sets ^^^and ^^^, for each BWP of a serving cell, the wireless device may be provided respective two sets ^^^,^and ^^^,^of periodic CSI-RS resource configuration indexes and corresponding two sets ^^^,^and ^^^,^of periodic CSI-RS resource configuration indexes and / or SS / PBCH block indexes by candidateBeamRSList1 and candidateBeamRSList2, respectively, for radio link quality measurements on the BWP of the serving cell. The set ^^^,^is associated with the set ^^^,^and the set ^^^,^is associated with the the set ^^^,^.

[0410] In an example, if the wireless device is not provided ^^^by failureDetectionResourcesToAddModList for a BWP of the serving cell, the wireless device may determine the set ^^^to include periodic CSI-RS resource configuration indexes with same values as the RS indexes in the RS sets indicated by TCI-State for respective CORESETs that the wireless device uses for monitoring PDCCH. If the UE is not provided ^^^,^or ^^^,^for a BWP of the serving cell, the wireless device may determine the set ^^^,^or ^^^,^to include periodic CSI-RS resource configuration indexes with same values as the RS indexes in the RS sets indicated by TCI-State for first and second CORESETs that the wireless device uses for monitoring PDCCH, where the wireless device is provided two coresetPoolIndex values 0 and 1 for the first and second CORESETs, or is not provided coresetPoolIndex value for the first CORESETs and is provided coresetPoolIndex value of 1 for the second CORESETs, respectively. If there are two RS indexes in a TCI state, the set ^^^includes RS indexes configured with qcl-Type set to 'typeD' for the corresponding TCI states. If a CORESET that the wireless device uses for monitoring PDCCH includes two TCI states and the wireless device is provided sfnSchemePdcch set to 'sfnSchemeA' or 'sfnSchemeB', the set ^^^includes RS indexes in the RS sets associated with the two TCI states.

[0411] The wireless device may expect the set ^^^to include up to two RS indexes. The wireless device may expect the set ^^^,^or the set ^^^,^to include up to a number of ^^^^RS indexes indicated by maxBFD-RSresourcesPerSetPerBWP. If the wireless device is not provided with ^^^,^or ^^^,^, and if a number of active TCI states for PDCCH receptions in the first or second CORESETs is larger than ^^^^, the wireless device may determine the set ^^^,^or ^^^,^to comprise periodic CSI-RS resource configuration indexes with same values as the RS indexes in the RS sets associated with the active TCI states for PDCCH receptions in the first or second CORESETs corresponding to search space sets according to anDocket No.: 24-1227PCT ascending order for monitoring periodicity. If more than one first or second CORESETs correspond to search space sets with same monitoring periodicity, the wireless device determines the order of the first or second CORESETs according to a descending order of a CORESET index.

[0412] In an example, a wireless device is not configured / provided with coresetPoolIndex or is provided coresetPoolIndex with a value of 0 for first CORESETs on an active DL BWP of a serving cell, or is provided coresetPoolIndex with a value of 1 for second CORESETs on the active DL BWP of the serving cells. In such a case, if the wireless device is provided with SSB-MTCAdditionalPCI, SSB indexes associated with a physical cell identity other than the one provided by physCellId in ServingCellConfigCommon may be configured in ^^^,^set and the corresponding ^^^,^set is associated with the physical cell identity.

[0413] The wireless device expects single port RS in the set ^^^, or ^^^,^, or ^^^,^. The wireless device expects single-port or two-port CSI-RS with frequency density equal to 1 or 3 REs per RB in the set ^^^, or ^^^,^, or ^^^,^.

[0414] In an example, thresholds Qout,LRand Qin,LRcorrespond to the default value of rlmInSyncOutOfSyncThreshold, as described in TS 38.133 for Qout, and to the value provided by rsrp- ThresholdSSB or rsrp-ThresholdBFR, respectively.

[0415] In an example, the physical layer of the wireless device assesses the radio link quality according to the set ^^^, ^^^,^, or ^^^,^, of resource configurations against the threshold Qout,LR. For the set ^^^, the wireless device assesses the radio link quality only according to SS / PBCH blocks on the PCell or the PSCell or periodic CSI-RS resource configurations that are quasi co-located, with the DM-RS of PDCCH receptions monitored by the wireless device. The wireless device applies the Qin,LR threshold to the L1- RSRP measurement obtained from a SS / PBCH block. The wireless device applies the Qin,LRthreshold to the L1-RSRP measurement obtained for a CSI-RS resource after scaling a respective CSI-RS reception power with a value provided by powerControlOffsetSS.

[0416] In non-DRX mode operation, the physical layer of the wireless device provides an indication to higher layers when the radio link quality for all corresponding resource configurations in the set ^^^, or in the set ^^^,^or ^^^,^that the wireless device uses to assess the radio link quality is worse than the threshold Qout,LR. The physical layer informs the higher layers when the radio link quality is worse than the threshold Qout,LR with a periodicity determined by the maximum between the shortest periodicity among the SS / PBCH blocks on the PCell or the PSCell and / or the periodic CSI-RS configurations in the set ^^^, ^^^,^, or ^^^,^that the wireless device uses to assess the radio link quality and 2 msec. In DRX mode operation, the physical layer provides an indication to higher layers when the radio link quality is worse than the threshold Qout,LRwith a periodicity (e.g., determined as described in TS 38.133).Docket No.: 24-1227PCT

[0417] In an example, for the PCell or the PSCell, upon request from higher layers, the wireless device provides to higher layers the periodic CSI-RS configuration indexes and / or SS / PBCH block indexes from the set ^^^, or ^^^,^, or ^^^,^and the corresponding L1-RSRP measurements that are larger than or equal to the Qin,LRthreshold.

[0418] In an example, for the SCell, upon request from higher layers, the wireless device indicates to higher layers whether there is at least one periodic CSI-RS configuration index or SS / PBCH block index from the set ^^^, or ^^^,^, or ^^^,^with corresponding L1-RSRP measurements that is larger than or equal to the Qin,LRthreshold, and provides the periodic CSI-RS configuration indexes and / or SS / PBCH block indexes from the set ^^^, or ^^^,^, or ^^^,^and the corresponding L1-RSRP measurements that are larger than or equal to the Qin,LRthreshold, if any.

[0419] In an example, for the PCell or the PSCell, a wireless device may be provided a CORESET through a link to a search space set provided by recoverySearchSpaceId configured by RRC message, for monitoring PDCCH in the CORESET. If the wireless device is provided recoverySearchSpaceId, the wireless device does not expect to be provided another search space set for monitoring PDCCH in the CORESET associated with the search space set provided by recoverySearchSpaceId.

[0420] In response to triggering the BFR comprising determining a candidate beam for the BFR procedure, the wireless device may transmit a preamble via a PRACH resource associated with the BFR procedure. In an example, for the PCell or the PSCell, the wireless device may be provided, by PRACH- ResourceDedicatedBFR (e.g., in the RRC messages), a configuration for PRACH transmission. For PRACH transmission in slot ^ and according to antenna port quasi co-location parameters associated with periodic CSI-RS resource configuration or with SS / PBCH block associated with index ^^^provided by higher layers, the wireless device monitors PDCCH in a search space set provided by recoverySearchSpaceId for detection of a DCI format with CRC scrambled by C-RNTI or MCS-C-RNTIstarting from slot ^ + 4 + 2$ ∙ &'(), where * is the SCS configuration for the PRACH transmission and&'() is a number of slots provided by K-Mac or &'() = 0 if K-Mac is not provided, within a windowconfigured by BeamFailureRecoveryConfig. in response to transmitting the preamble, the wireless device may montor the PDCCH via the search space provided by recoverySearchSpaceId for detection of the DCI format. For PDCCH monitoring in a search space set provided by recoverySearchSpaceId and for corresponding PDSCH reception, the wireless device may assume the same antenna port quasi-collocation parameters as the ones associated with index ^^^until the wireless device receives by higher layers an activation for a TCI state or any of the parameters tci-StatesPDCCH-ToAddList and / or tci-StatesPDCCH- ToReleaseList. After the wireless device detects a DCI format with CRC scrambled by C-RNTI or MCS-C- RNTI in the search space set provided by recoverySearchSpaceId, the wireless device continues to monitor PDCCH candidates in the search space set provided by recoverySearchSpaceId until the UEDocket No.: 24-1227PCT receives a MAC CE activation command for a TCI state or tci-StatesPDCCH-ToAddList and / or tci- StatesPDCCH-ToReleaseList.

[0421] In an example, for the PCell or the PSCell, after 28 symbols from a last symbol of a first PDCCH reception in a search space set provided by recoverySearchSpaceId for which the wireless device detects a DCI format with CRC scrambled by C-RNTI or MCS-C-RNTI and until the wireless device receives an activation command for PUCCH-SpatialRelationInfo or is provided PUCCH-SpatialRelationInfo for PUCCH resource(s), the UE transmits a PUCCH on a same cell as the PRACH transmission using a same spatial filter as for the last PRACH transmission and a power determined (e.g., specified in clause 7.2.1 of TS38.213) with ^- = 0, ^. = ^^^ , and ^ = 0.

[0422] In an example, for the PCell or the PSCell and for sets ^^^and ^^^, after 28 symbols from a last symbol of a first PDCCH reception in a search space set provided by recoverySearchSpaceId where a wireless device detects a DCI format with CRC scrambled by C-RNTI or MCS-C-RNTI, the wireless device may assume same antenna port quasi-collocation parameters as the ones associated with index ^^^for PDCCH monitoring in a CORESET with index 0.

[0423] In an example, if a wireless device is provided TCI-State_r17 indicating a unified TCI state for the PCell or the PSCell, after a number of symbols from a last symbol of a first PDCCH reception in a search space set provided by recoverySearchSpaceId where the wireless device detects a DCI format with CRC scrambled by C-RNTI or MCS-C-RNTI, the wireless device, if if AdditionalPCIInfo is not provided, monitors PDCCH in all CORESETs, and receives PDSCH and aperiodic CSI-RS in a resource from a CSI-RS resource set with same indicated TCI state as for the PDCCH and PDSCH, using the same antenna port quasi co-location parameters as the ones associated with the corresponding index ^new, if any, and transmits PUCCH, PUSCH and SRS that uses a same spatial domain filter with same indicated TCI state as for the PUCCH and the PUSCH, using a same spatial domain filter as for the last PRACH transmission.

[0424] In an example, if a PDCCH reception includes two PDCCH candidates from two linked search space sets based on searchSpaceLinking, the last symbol of the PDCCH reception is the last symbol of the PDCCH candidate that ends later. The PDCCH reception includes the two PDCCH candidates also when the wireless device is not required to monitor one of the two PDCCH candidates.

[0425] In an example, for the PCell or the PSCell, if a BFR MAC CE is provided in Msg3 or MsgA of contention based random access procedure, and if a PUCCH resource is provided with PUCCH- SpatialRelationInfo, after 28 symbols from the last symbol of the PDCCH reception that determines the completion of the contention based random access procedure, the wireless device transmits the PUCCH on a same cell as the PRACH transmission using a same spatial filter as for the last PRACH transmissionand a power determined with ^- = 0, ^. = ^^^ , and ^ = 0, where ^^^ is the SS / PBCH block indexselected for the last PRACH transmission.Docket No.: 24-1227PCT

[0426] In an example, if a wireless device is provided TCI-State_r17 indicating a unified TCI state for the PCell or the PSCell and the wireless device provides BFR MAC CE in Msg3 or MsgA of contention based random access procedure, after a number of symbols from the last symbol of the PDCCH reception that determines the completion of the contention based random access procedure, the wireless device, if AdditionalPCIInfo is not provided, monitors PDCCH in all CORESETs, and receives PDSCH and aperiodic CSI-RS resource in a CSI-RS resource set with same indicated TCI state as for the PDCCH and PDSCH using the same antenna port quasi co-location parameters as the ones associated with the corresponding index ^new, if any, and transmits PUCCH, PUSCH and SRS that uses a same spatial domain filter with same indicated TCI state as for the PUCCH and PUSCH, using a same spatial domain filter as for the last PRACH transmission.

[0427] In an example, a wireless device may be provided, by schedulingRequestID-BFR-SCell, a configuration for PUCCH transmission with a link recovery request (LRR) for the wireless device to transmit PUCCH. If the PCell or the PSCell is associated with sets ^^^,^and ^^^,^, and with sets ^^^,^and ^^^,^, the wireless device may be provided by schedulingRequestIDForMTRPBFR a first configuration for PUCCH transmission with a LRR and, if the wireless device provides twoLRRcapability, a second configuration for PUCCH transmission with a LRR. If the wireless device is provided only the first configuration, the wireless device transmits a PUCCH with LRR for either set ^^^,^or ^^^,^. If the wireless device is provided both the first and second configurations, the wireless device uses the first configuration to transmt a PUCCH with LRR associated with set ^^^,^and the second configuration to transmit a PUCCH with LRR associated with set ^^^,^.

[0428] In an example, the wireless device may provide in a first PUSCH MAC CE index(es) for at least corresponding SCell(s) with radio link quality worse than Qout,LR, indication(s) of presence of ^newfor corresponding SCell(s), and index(es) ^newfor a periodic CSI-RS configuration or for a SS / PBCH block provided by higher layers, if any, for corresponding SCell(s). After 28 symbols from a last symbol of a PDCCH reception with a DCI format scheduling a PUSCH transmission with a same HARQ process number as for the transmission of the first PUSCH and having a toggled NDI field value, the wireless device monitors PDCCH in all CORESETs on the SCell(s) indicated by the MAC CE using the same antenna port quasi co-location parameters as the ones associated with the corresponding index(es) ^new, if any, and transmits PUCCH on a PUCCH-SCell using a same spatial domain filter as the one corresponding to ^new,if any, for periodic CSI-RS or SS / PBCH block reception, and using a power determined with ^u = 0,^d = ^new, and ^ = 0, if the wireless device is provided PUCCH-SpatialRelationInfo for the PUCCH and aPUCCH with the LRR was either not transmitted or was transmitted on the PCell or the PSCell, and the PUCCH-SCell is included in the SCell(s) indicated by the MAC-CE, where the SCS configuration for the 28Docket No.: 24-1227PCT symbols is the smallest of the SCS configurations of the active DL BWP for the PDCCH reception and of the active DL BWP(s) of the at least one SCell.

[0429] In an example, if a wireless device is provided TCI-State_r17 indicating a unified TCI state, after a number of symbols from a last symbol of a PDCCH reception with a DCI format scheduling a PUSCH transmission with a same HARQ process number as for the transmission of the first PUSCH and having a toggled NDI field value, the wireless device monitors PDCCH in all CORESETs, and receives PDSCH and aperiodic CSI-RS in a resource from a CSI-RS resource set using the same antenna port quasi co-location parameters as the ones associated with the corresponding index ^new, if any, and transmits PUCCH, PUSCH and SRS that uses a same spatial domain filter with same indicated TCI state as for the PUCCH and PUSCH, using a same spatial domain filter as the one corresponding to ^new, if any.

[0430] In an example, for serving cells associated with sets ^^^,^and ^^^,^, and with sets ^^^,^and ^^^,^, the wireless device may provide in a second PUSCH MAC CE index(es) for cell(s) with ^^^,^and / or ^^^,^having radio link quality worse than Qout,LR, the index(es) of those ^^^,^and / or ^^^,^, and indication(s) of presence of ^newand of index(es) ^new, if any, from corresponding sets ^^^,^and / or ^^^,^for the serving cells.

[0431] In an example, for serving cells associated with sets ^^^,^and ^^^,^, and with sets ^^^,^and ^^^,^, and having radio link quality worse than Qout,LR, after 28 symbols from a last symbol of a first PDCCH reception with a DCI format scheduling a PUSCH transmission with a same HARQ process number as for transmission of the second PUSCH and having a toggled NDI field value, the wireless device may assume antenna port quasi-collocation parameters corresponding to ^newfrom ^^^,^, if any, for the first CORESETs and corresponding to ^newfrom ^^^,^, if any, for the second CORESETs, where the SCS configuration for the 28 symbols is the smallest of the SCS configurations of the active DL BWP for the PDCCH reception and of the active DL BWP(s) of the serving cells. In the example, the wireless device may monitor PDCCH in all CORESETs, on the SCell (s) indicated by the MAC CE and may receive PDSCH and aperiodic CSI- RS resource in a CSI-RS resource set using the same antenna port quasi co-location parameters as the ones associated with the corresponding index ^newif SSB-MTC-AdditionalPCI is not provided. The wireless device may transmit PUSCH, PUCCH and SRS that uses a same spatial domain filter with same indicated TCI state as for the PUSCH and PUCCH, using a same spatial domain filter as the one corresponding to ^new.

[0432] For serving cells associated with sets q^^,^and q^^,^, and q^^,^and q^^,^, and having radio link quality worse than Qout,LR,, after 28 symbols from a last symbol of a first PDCCH reception with a DCI format scheduling a PUSCH transmission with a same HARQ process number as for transmission of the second PUSCH and having a toggled NDI field value, the wireless device may assume antenna port quasi- collocation parameters corresponding to ^newfrom q^^,^for the first CORESETs and corresponding to ^newDocket No.: 24-1227PCT from q^^,^for the second COERSETS, where the SCS configuration for the 28 symbols is the smallest of the SCS configurations of the active DL BWP for the PDCCH reception and of the active DL BWP(s) of the serving cells.

[0433] For a serving cell associated with sets q^^,^and q^^,^, and q^^,^and q^^,^, and having radio link quality worse than Qout,LR,and if a wireless device is with dl- StateList or TCI-UL-State and is indicated a first TCI-state or TCI-UL-StateUL-state, after 28 symbols from a last symbol of a first PDCCH reception with a DCI format scheduling a PUSCH transmission with a same HARQ process number as for the transmission of the second PUSCH and having a toggled NDI field,

[0434] the wireless device may monitor PDCCH that applies the first TCI-State, and may receive PDSCH and aperiodic CSI-RS resource that apply the first TCI-State, using same antenna port quasi co-location parameters as the ones associated with a corresponding index ^newfrom ^^^,^, if any, on the serving cell. The wireless device may monitor PDCCH that applies the second TCI-State, and may receive PDSCH and aperiodic CSI-RS resource that apply the first TCI-State, using same antenna port quasi co-location parameters as the ones associated with a corresponding index ^newfrom ^^^,^, if any, on the serving cell. The wireless device may transmit PUSCH, PUCCH, and SRS that apply the first TCI-State or TCI-UL-State using a same spatial domain filter as the one corresponding to ^newfrom ^^^,^, if any, on the serving cell. The wireless device may transmit PUSCH, PUCCH, and SRS that apply the second TCI-State or TCI-UL- State using a same spatial domain filter as the one corresponding to ^newfrom ^^^,^, if any, on the serving cell. In the example, the SCS configuration for the 28 symbols is the smallest of the SCS configurations of the active DL BWP for the PDCCH reception and of the active DL BWP(s) of the serving cells.

[0435] For a serving cell associated with sets q^^,^and q^^,^, and q^^,^and q^^,^, and having radio link quality worse than Qout,LR, and if a wireless device is provided with two coresetPoolIndex values 0 and 1 for the first and second CORESETs, or is not provided coresetPoolIndex value for the first CORESETs and is provided coresetPoolIndex value of 1 for the second CORESETs respectively, and the wireless device is provided dl-OrJointTCI-StateList or TCI-UL-State, after 28 symbols from a last symbol of a first PDCCH reception with a DCI format scheduling a PUSCH transmission with a same HARQ process number as for the transmission of the second PUSCH and having a toggled NDI field,

[0436] the wireless device may monitor PDCCH in the first CORESETs, and may receive PDSCH scheduled / activated by PDCCH in the first CORESETS and aperiodic CSI-RS resource that apply a TCI- state specific to the first CORESETs, using same antenna port quasi co-location parameters as the ones associated with a corresponding index ^newfrom ^^^,^, if any, on the serving cell. The wireless device may monitor PDCCH in the second CORESETs, and may receive PDSCH scheduled / activated by PDCCH in the second CORESETS and aperiodic CSI-RS resource that apply a TCI-state specific to the secondDocket No.: 24-1227PCT CORESETs, using same antenna port quasi co-location parameters as the ones associated with a corresponding index ^newfrom ^^^,^, if any, on the serving cell. The wireless device may transmit PUSCH, PUCCH, and SRS that apply a TCI-State or TCI-UL-State specific to the first CORESETs using a same spatial domain filter as the one corresponding to ^newfrom ^^^,^, if any, on the serving cell. The wireless device may transmit PUSCH, PUCCH, and SRS that apply a TCI-State or TCI-UL-State specific to the second CORESETs using a same spatial domain filter as the one corresponding to ^newfrom ^^^,^, if any, on the serving cell. In the example, the SCS configuration for the 28 symbols is the smallest of the SCS configurations of the active DL BWP for the PDCCH reception and of the active DL BWP(s) of the serving cells.

[0437] In the example, the SCS configuration for the 28 symbols is the smallest of the SCS configurations of the active DL BWP for the PDCCH reception and of the active DL BWP(s) of the serving cells.

[0438] In an example, when performing the BFR procedure, the MAC entity of the wireless device may be configured by RRC per Serving Cell with a beam failure recovery procedure which is used for indicating to the serving gNB of a new SSB or CSI-RS when beam failure is detected on the serving SSB(s) / CSI-RS(s). Beam failure is detected by counting beam failure instance indication from the lower layers to the MAC entity. If beamFailureRecoveryConfig is reconfigured by upper layers during an ongoing Random Access procedure for beam failure recovery for SpCell, the MAC entity shall stop the ongoing Random Access procedure and initiate a Random Access procedure using the new configuration. In an example, the one or more RRC messages, may further comprise, for the BFR procedure, configuration parameters (e.g., in the BeamFailureRecoveryConfig, BeamFailureRecoverySCellConfig, and the RadioLinkMonitoringConfig) for the Beam Failure Detection and Recovery procedure, comprising beamFailureInstanceMaxCount for the beam failure detection, beamFailureDetectionTimer for the beam failure detection, beamFailureRecoveryTimer for the beam failure recovery procedure, rsrp-ThresholdSSB: an RSRP threshold for the SpCell beam failure recovery, rsrp-ThresholdBFR: an RSRP threshold for the SCell beam failure recovery, powerRampingStep: powerRampingStep for the SpCell beam failure recovery, powerRampingStepHighPriority: powerRampingStepHighPriority for the SpCell beam failure recovery, preambleReceivedTargetPower: preambleReceivedTargetPower for the SpCell beam failure recovery, preambleTransMax: preambleTransMax for the SpCell beam failure recovery, ssb-perRACH-Occasion: ssb-perRACH-Occasion for the SpCell beam failure recovery using contention-free Random Access Resources, ra-ResponseWindow: the time window to monitor response(s) for the SpCell beam failure recovery using contention-free Random Access Resources, prach-ConfigurationIndex: prach- ConfigurationIndex for the SpCell beam failure recovery using contention-free Random Access Resources, ra-ssb-OccasionMaskIndex: ra-ssb-OccasionMaskIndex for the SpCell beam failure recovery using contention-free Random Access Resources, ra-OccasionList: ra-OccasionList for the SpCell beam failureDocket No.: 24-1227PCT recovery using contention-free Random Access Resources, candidateBeamRSList: list of candidate beams for SpCell beam failure recovery, candidateBeamRSSCellList: list of candidate beams for SCell beam failure recovery and etc.

[0439] In an example, one or more variables are used for the beam failure detection procedure. The one or more variables comprise BFI_COUNTER (per Serving Cell), which is a counter for beam failure instance indication which is initially set to 0. In an example, the MAC entity of the wireless device shall, for each Serving Cell configured for beam failure detection, start or restart the beamFailureDetectionTimer, if beam failure instance indication has been received from lower layers, and increment BFI_COUNTER by 1. If BFI_COUNTER >= beamFailureInstanceMaxCount, the MAC entity of the wireless device may trigger a BFR for this Serving Cell if the Serving Cell is SCell or initiate a Random Access procedure on the SpCell if the Serving Cell is SpCell. if the beamFailureDetectionTimer expires or if beamFailureDetectionTimer, beamFailureInstanceMaxCount, or any of the reference signals used for beam failure detection is reconfigured by upper layers associated with this Serving Cell, the MAC layer of the wireless device set BFI_COUNTER to 0. If the Serving Cell is SpCell and the Random Access procedure initiated for SpCell beam failure recovery is successfully completed, the MAC layer of the wireless device set BFI_COUNTER to 0, stop the beamFailureRecoveryTimer, if configured, and / or consider the Beam Failure Recovery procedure successfully completed. If the Serving Cell is SCell, and a PDCCH addressed to C-RNTI indicating uplink grant for a new transmission is received for the HARQ process used for the transmission of the BFR MAC CE or Truncated BFR MAC CE which contains beam failure recovery information of this Serving Cell or if the SCell is deactivated, the MAC layer of the wireless device set BFI_COUNTER to 0 and / or consider the Beam Failure Recovery procedure successfully completed and cancel all the triggered BFRs for this Serving Cell.

[0440] In an example, the MAC entity of the wireless device instructs the Multiplexing and Assembly procedure to generate the BFR MAC CE if the Beam Failure Recovery procedure determines that at least one BFR has been triggered and not cancelled for an SCell for which evaluation of the candidate beams has been completed and if UL-SCH resources are available for a new transmission and if the UL-SCH resources may accommodate the BFR MAC CE plus its subheader as a result of LCP. The MAC entity of the wireless device instructs the Multiplexing and Assembly procedure to generate the Truncated BFR MAC CE if UL-SCH resources are available for a new transmission and if the UL-SCH resources may accommodate the Truncated BFR MAC CE plus its subheader as a result of LCP, otherwise, the MAC layer of the wireless device triggers the SR for SCell beam failure recovery for each SCell for which BFR has been triggered, not cancelled, and for which evaluation of the candidate beams has been completed.Docket No.: 24-1227PCT

[0441] In an example, all BFRs triggered for an SCell are cancelled when a MAC PDU is transmitted and this PDU includes a BFR MAC CE or Truncated BFR MAC CE which contains beam failure information of that SCell.

[0442] In the present disclosure, a PRACH occasion may be referred as a RO. A RO may be referred a RACH occasion, a random access resource occasion, a random access resource, a random access opportunity, a PRACH resource, a RACH resource, and / or like.

[0443] In the present disclosure, a RO may refer a PRACH occasion, a RACH ocassion, a PUSCH occasion for a Type-2 random access procedure, a PUSCH occasion for a random access procedure, a PUSCH comprising Msg 1 (e.g., PUSCH-Msg1, PUSCH with Msg1) occasion, and / or the like.

[0444] In the present disclosure, a SSB may be referred as a periodic SSB, a non-on-demand SSB, a CD- SSB, an NCD-SSB and / or the like.

[0445] In the present disclosure, an on-demand SSB may be referred as a non-periodic SSB, a semi- persistent SSB, an additional SSB, a SCell-activation assisting SSB, a non CD-SSB, a non NCD-SSB, and / or the like.

[0446] In the present disclosure, a symbol may refer an OFDM symbol, a symbol based on a subcarrier spacing of a serving cell where the symbol is applied, a time duration based on a subcarrier spacing of a serving cell where the symbol is used, and / or the like.

[0447] In the present disclosure, ^newmay be referred as a candidate beam, a candidate beam index, a BFR recovery beam, a recoverya new beam, a recovery TCI state, a recovery RS, a new beam index, a recovery RS index, a BFR new beam index, and / or the like.

[0448] In the present disclosure, a cell comprises a SSB may refer that a base station transmits the SSB via / on the cell.

[0449] In the present disclosure, a case where a wireless device ‘prioritizes A over B’ may refer the wireless device is a half-duplex in receiving or transmitting and may select A and drop B when the wireless device is not able to receive / transmit A and transmit / receive B at a given time.

[0450] In the present disclosure, an on-demand RS (e.g., SSB) may be a semi-periodic RS (e.g., SSB) or a semi-persistent RS (e.g., SSB) but is not a periodic RS (e.g., SSB). A RS is a semi-periodic RS, where a wireless device may expect that the RS is maintained as active until a serving cell of RS is deactivated, after the RS is activated. In another example, a RS is a semi-periodic / semi-persistent RS, where a wireless device may expect that the RS is maintained as active where the wireless device is configured to perform measurements on the RS for radio link monitoring, and / or beam management, and / or beam failure recovery and / or radio resource monitoring. In another example, if the on-demand SSB is transmitted without always-on SSB on the cell, the on-demand SSB may be referred as a semi-persistent / periodic RS. The RS may be a SSB or a CSI-RS or a PRS. In an example, an on-demand SSB that is maintained asDocket No.: 24-1227PCT active until a serving cell of the on-demand SSB is deactivated, after being activated, may be referred as a ‘semi-periodic SSB’ or a ‘semi-persistent SSB’. The semi-periodic SSB, that is the second on-demand SSB, may be activated before the serving cell is activated, or during the serving cell is activated or after the serving cell is activated. In an example, a semi-periodic SSB, that is an on-demand SSB, may be referred as a first type on-demand RS (e.g., type1-od-SSB). A non-semi-periodic SSB, that is an on-demand SSB, may be referred as a second type on-demand SSB (e.g., type2-od-SSB).

[0451] A base station may transmit configuration parameters (e.g., RACH-ConfigCommon and / or RACH- ConfigGeneric) to indicate one or more random access resources via a cell for a plurality of wireless devices. The base station may also transmit one or more on-demand SSBs via the cell, for example, to assist a time / frequency tracking of one or more of the plurality of wireless devices. A wireless device of the plurality of wireless device may determine one or more valid ROs based on the configuration parameters.

[0452] In existing technologies, a wireless device may determine a RO as invalid in case the RO precedes a CD-SSB in a slot comprising the RO by a gap that is smaller than a value. In other words, in case the gap between the RO and the CD-SSB is smaller than the value, the wireless device may determine the RO as invalid. However, existing technologies do not specifically address how to determine the RO as valid or invalid in case the SSB is an on-demand SSB which is neither a CD-SSB nor an NCD-SSB.

[0453] The above described method of determining whether the RO is valid or not in case the SSB is a CD-SSB may also be applicable in case the SSB is an on-demand SSB. More specifically, the wireless device may determine the RO as invalid in case the RO precedes an active on-demand SSB in a slot comprising the RO by a gap that is smaller than a value.

[0454] However, there may be a scenario where the RO should be determined as valid even when the gap between the RO and an on-demand SSB in a slot comprising the RO is less than the value. This scenario is explained below with respect to FIG.23. As shown in FIG.23, a base station may transmit a (periodic) SSB burst (e.g., comprising non-on-demand SSB(s) or always-on SSB(s)) via a serving cell (or a cell) during Frame #i. Based on a periodicity of the periodic SSB burst, a wireless device may expect to receive one or more SSBs, of the (periodic) SSB burst, of the serving cell during Frame #i. The one or more SSBs are transmitted SSB(s) in the SSB burst based on ssb-PositionsInBurst. FIG.23 illustrates a single SSB transmission (SSB in FIG.23) in each SSB burst.

[0455] In contrast to Frame #i, during Frame #j, based on the periodicity of the periodic SSB burst, the wireless device may not expect to receive one or more SSBs, of the (periodic) SSB burst, of the serving cell. During Frame #j, the base station may additionally and / or optionally transmit an on-demand SSB burst comprising one or more on-demand SSBs. FIG.23 illustrates a single on-demand SSB transmission (OD- SSB in FIG.23) in each on-demand SSB burst during Frame #j. During Frame #j, the wireless device may receive one or more RRC messages indicating one or more ROs of the serving cell. For example, four timeDocket No.: 24-1227PCT occasions (from #1 to #4) with two ROs in each time occasion may be determined based on the one or more RRC messages for the one or more ROs.

[0456] In the scenario shown in FIG.23, the wireless device may determine that two ROs in a first time occasion (#1) of Frame #i are valid as a time gap between the last SSB symbol in Slot #1 and the two ROs in Slot #1 is larger than or equal to a value (e.g., Ngap). On the contrary, the wireless device may determine that two ROs in a second time occasion (#2) of Frame #i are invalid as the two ROs in Slot #2 precede a SSB in Slot #2 and a time gap between the two ROs in Slot #2 and the SSB in Slot #2 is smaller than the value. Similarly, the wireless device may determine that two ROs in Slot #3 of Frame #i are invalid as the gap between the two ROs and the SSB in Slot #3 is less than the value, and determine that two ROs in Slot #4 of Frame #i are valid as there is no SSB in Slot #4.

[0457] As further shown in FIG.23, in contrast to Frame #i, during Frame #j, the base station may not transmit the periodic SSB burst, and thus, the wireless device may not receive any (periodic) SSB via the serving cell during Frame #j. Instead, the base station may transmit on-demand SSBs. However, as briefly explained above, existing technologies do not address how to determine whether ROs are valid or not in case SSBs are on-demand SSBs. For example, the on-demand SSB burst may comprise the same set of SSB indexes as the periodic SSB burst. Frame #j may comprise a same set of symbols where on-demand SSBs are transmitted compared to a set of symbols where (periodic) SSBs are transmitted during Frame #i.

[0458] Similar to when the SSBs are CD-SSBs, in case the SSBs are on-demand SSBs, the wireless device may determine that the RO in Slot#2 during Frame #j is invalid because the gap between the RO in Slot #2 and the on-demand SSBs in Slot #2 is less than the value. Similarly, the wireless device may determine that the RO in Slot#3 during Frame #j is invalid because the gap between the RO in Slot #3 and the on-demand SSBs in Slot #3 is less than the value.

[0459] However, there may be a scenario where determining a certain RO (e.g., one of the ROs in Slots #2 and #3 of Frame #j) as invalid based on that the gap between the RO and the on-demand SSBs is less than the value may be problematic.

[0460] For example, let’s assume that the cell serves a first wireless device and a second wireless device, and that the first wireless device is configured with on-demand SSBs while the second wireless device is not configured with on-demand SSBs. During Frame #j, the first wireless device may determine that the ROs in Slot #2 are invalid because the gap between the on-demand SSB in Slot #2 and the ROs in Slot #2 is less than a value. In contrast, because the second wireless device is not configured with on-demand SSBs of the cell, the second wireless device may not be aware of the presence of the on-demand SSBs, and thus may determine that the ROs in Slot #2 are valid. This may lead different mappings between one or more SSBs and one or more valid ROs based on the one or more random access resources for the second wireless device and the first wireless device respectively. For example, a second RO of the one orDocket No.: 24-1227PCT more random access may be mapped to a first SSB for the second wireless device while being mapped to a second SSB for the first wireless device. This may increase complexity in a base station to handle multiple mappings. This may lead performance degradation in a random-access procedure. For example, the base station may not be able to determine a corresponding SSB to the second RO between the first SSB and the second SSB, without knowing which device has sent a preamble via the second RO.

[0461] In a summary, existing technologies do not specify a wireless device behavior in determining a RO as valid or invalid when a gap between the RO and an on-demand SSB in a slot including the RO is less than a value. Also, existing technologies do not address determination of random access resources and mapping between the random access resources and one or more SSB indexes of a serving cell in a consistent / efficient manner, when the serving cell comprises one or more on-demand SSBs / SSB indexes.

[0462] In order to solve the above described problems, according to embodiments of this disclosure, there is provided a method. The method comprises receiving, by a wireless device, one or more RRC messages. The RRC messages indicate a synchronization signal block (SSB) during a first symbol of a cell and a random access resource occasion (RO) during a second symbol of the cell. A time gap between the second symbol and the first symbol is less than a value. The method further comprises determining the RO as valid based on the SSB being an on-demand SSB, and transmitting a preamble based on the RO via the cell.

[0463] Embodiments of the present disclosure allow solving potential misalignment(s) of RO / POs among wireless devices in a serving cell. Additionally or alternatively, the embodiments address RO / PO determination(s) in the presence of on-demand SSBs in the serving cell.

[0464] For example, the determination of the uplink resource occasion (e.g., the PO or the RO) as valid based on the SSB being an on-demand SSB is implemented by the wireless device does not consider the SSB to determine the uplink resource occasion as invalid in response to the SSB being the on-demand SSB.

[0465] For example, the SSB may be during one or more first symbols, where the first symbol is a last (latest) symbol of the one or more first symbols. For example, the uplink resource occasion (e.g., the PO or the RO) may be during one or more second symbols, where the second symbol is a first (earliest) symbol of the one or more second symbols. The time gap is from the first symbol to the second symbol in this case.

[0466] In another example, the SSB may be during one or more first symbols, where the first symbol is a first (earliest) symbol of the one or more first symbols. For example, the uplink resource occasion (e.g., the PO or the RO) may be during one or more second symbols, where the second symbol is a last (latest) symbol of the one or more second symbols. The time gap is from the second symbol to the first symbol in this case.Docket No.: 24-1227PCT

[0467] In the example, the one or more RRC messages may further indicates a second SSB, of the cell, during a third symbol of the cell. The one or more RRC messages may further indicate a second uplink resource occasion (e.g., a second PO or a second RO), of the cell, during a fourth symbol of the cell. For example, a second time gap between the third symbol and the fourth symbol may be smaller than the value (e.g., Ngap). The wireless device may determine the second uplink resource occasion as invalid, wherein the second SSB is a (periodic) SSB or a cell-defining SSB. In the example, the second may be during one or more third symbols comprising the third symbol. The second uplink resource occasion may be during one or more fourth symbols comprising the fourth symbol. The second time gap may be from the third symbol to the fourth symbol. In the example, the third symbol is a last (latest) symbol of the one or more third symbols, and the fourth symbol is a first (earliest) symbol of the one or more fourth symbols. The second time gap may be from the fourth symbol to the third symbol. In the example, the third symbol is a first (earliest) symbol of the one or more third symbols, and the fourth symbol is a last (latest) symbol of the one or more fourth symbols.

[0468] In the example, the one or more RRC messages may further indicate a third SSB, of the cell, during one or more fifth symbols of the cell. The third SSB is a second on-demand SSB. A third time gap between / from the last symbol of the one or more second symbols of the uplink resource occasion, that is valid, and / to the first symbol of the one or more fifth symbol, where the third gap is smaller than the value. In the example, the uplink resource occasion may be the RO. The wireless device may drop or skip receiving / measuring of the third SSB based on the third gap being smaller than the value.

[0469] In an example, the wireless device may receive a DCI (format) scheduling an uplink transmission (e.g., a PUCCH, a PUSCH, a SRS, a PRACH) during a third symbol of the one or more first symbols. The uplink transmission may overlap, in time, with the on-demand SSB. In the example, the wireless device may transmit the uplink transmission during the third symbol based on the SSB being the on-demand SSB. When the wireless device may not support simultaneous reception of the SSB and transmission of the uplink transmission, the wireless device may prioritize to transmit the dynamically scheduled uplink transmission (e.g., the uplink transmission scheduled via the DCI (format)) than receiving the on-demand SSB. In the example, the uplink transmission may be via one of PUCCH, PUSCH, SRS, PRACH and / or a combination thereof. Alternatively, in a different example, the wireless device may drop the uplink transmission during the third symbol in response to the uplink transmission overlapping with the SSB. In the example, the SSB is the on-demand SSB. In the example, the wireless device may prioritize to receive the SSB and may drop the uplink transmission.

[0470] In an example, the wireless device may receive one or more second RRC messages comprising TDD UL / DL configuration parameters (e.g., tdd-UL-DL-ConfigurationCommon, tdd-UL-DL- ConfigurationDedicated) of the cell. The TDD UL / DL configuration parameters may indicate the one orDocket No.: 24-1227PCT more first symbols as flexible. The wireless device may receive a DCI format of a slot formation indicator (SFI) for the cell. In the example, the SFI may indicate the one or more first symbols as uplink or flexible. In an example, a base station may configure / scheduling downlink resource or uplink resource via / during a symbol indicated as flexible based on one or more downlink commands (e.g., via RRC, MAC CE, DCI).

[0471] In an example embodiment, a base station may transmit configuration parameters of on-demand SSBs via a ServingCellConfig (e.g., ServingCellConfigCommon IE, ServingCellConfig IE) to a plurality of wireless devices of a serving cell. It may be broadcasted via SIB(s) and / or may be transmitted via RRC messages. In the example, a wireless device of the plurality of wireless devices may determine a RO, for the serving cell, based on an on-demand SSB regardless of active / inactive state of the on-demand SSB. For example, the wireless device may receive a ssb-PositionsInBurst for the on-demand SSBs. The wireless device may determine potentially transmitted on-demand SSBs (e.g., potential on-demand SSB(s)) in an on-demand SSB burst based on the ssb-PositionsInBurst. The potential on-demand SSB(s) are transmitted if the on-demand SSB burst is activated for the serving cell. The potential on-demand SSB(s) are not transmitted if the on-demand SSB burst is deactivated for the serving cell.

[0472] The wireless device may determine the RO based on a time relationship between the RO and the potential on-demand SSB(s) regardless of transmission of the potential on-demand SSB(s).

[0473] In other words, regardless the on-demand SSBs are activated or deactivated, the wireless device may consider the on-demand SSBs for determining a RO as valid or invalid. For example, the wireless device may determine a RO as invalid, where the RO precedes the potential on-demand SSB(s). The potential on-demand SSB(s) may comprise transmitted / active on-demand SSB(s) or may comprise inactive on-demand SSB(s).

[0474] In an example, the wireless device may consider an on-demand SSB to invalidate a RO in response to the configuration parameters of the on-demand SSBs, being present in a SIB1 of the serving cell or ServingCellConfigCommon of the serving cell. For example, when the configuration parameters of the on-demand SSBs are broadcasted via SIB(s) to a plurality of wireless devices of the serving cell or are comprised in serving cell common parameters, the wireless device may consider the on-demand SSBs in determining valid ROs. Otherwise (e.g., the configuration parameters of the on-demand SSBs are comprised in serving cell dedicated parameters to the wireless device), the wireless device may not determine the RO as invalid based on a time relationship between the RO and the on-demand SSB. The wireless device may not consider the on-demand SSBs in determining valid ROs in the case.

[0475] Example embodiments of the present disclosure may solve the RO determination with on-demand SSBs.

[0476] In existing technologies, the wireless device may determine a set of ROs as valid based on determining valid ROs based on CD-SSBs but not based on NCD-SSBs nor on-demand SSBs. TheDocket No.: 24-1227PCT existing technologies do not address how to handle the on-demand SSBs, which the wireless device may not be capable of receiving, with half-duplex capability, due to insufficient time to switch from transmission (e.g., via a RO of the set of ROs) to reception.

[0477] In an example, a wireless device receives one or more RRC messages indicating / comprising configuration parameters of a serving cell. The configuration parameters may indicate / comprise parameters for on-demand SSBs of the serving cell. The configuration parameters may also indicate / comprise parameters for random access resources (or ROs) via the serving cell. The configuration parameters may optionally indicate SSBs of the serving cell. The wireless device may determine valid ROs of the ROs based on the SSBs. In the example, for a set of symbols of a slot comprising both a valid PRACH occasion (RO) in the slot and Ngap symbols before the valid RO, the wireless device may not receive / measure / monitor an on-demand SSB, of the on-demand SSBs, in the slot if a reception of the on- demand SSB would overlap with any symbol from the set of symbols.

[0478] In existing technologies, a wireless device may determine random access resources or ROs of a cell based on one or more SSBs via the cell. The wireless device may perform a random access procedure based on the random access resources and the one or more SSBs via the cell. The existing technologies do not address whether the wireless device is allowed to or is configured to perform a random access procedure via the cell in response to the cell comprising / transmitting on-demand SSBs and not comprising / transmitting CD-SSBs nor NCD-SSBs. Based on existing technologies, the wireless device may perform the random access procedure based on the on-demand SSBs. The existing technologies do not address whether the wireless device continues or stop / deactivate the random access procedure in response to the on-demand SSBs being deactivated.

[0479] In an example, a wireless device may receive one or more RRC messages indicating on-demand SSBs of a serving cell. The one or more RRC messages further indicates ROs or random access resources via the serving cell. The wireless device may not determine one or more valid ROs from the ROs in response to an absence of CD-SSB or NCD-SSB via the serving cell. The wireless device may be configured not to perform a random access procedure via the serving cell in response to the absence of CD-SSB or NCD-SSB via the serving cell. In the example, the wireless device may expect to receive a PDCCH order initiating / triggering a PRACH transmission (e.g., initiating a random access procedure) via the serving cell, when / based on the serving cell comprises CD-SSB or NCD-SSB. Otherwise, the wireless device may not expect to receive a PDCCH order for a PRACH transmission via the serving cell. Alternatively, if a SIB1 of the serving cell or ServingCellConfigCommon (e.g., cell common parameters) of the serving cell comprises configuration parameters of the on-demand SSBs, the wireless device may determine valid ROs of the ROs based on the on-demand SSBs. In other words, the wireless device is configured / expected to perform a random access procedure based on the ROs via the serving cell. In theDocket No.: 24-1227PCT example, the serving cell is an SSB-less cell (e.g., Case #1 in FIG.20). The wireless device may receive a PDCCH order triggering a PRACH transmission via the serving cell based on the on-demand SSBs.

[0480] In existing technologies, a wireless device may indicate a candidate beam, for a beam failure recovery (BFR) procedure, from one or more periodic RSs (e.g., CSI-RS / SSB) satisfying conditions (e.g., measured channel quality exceed one or more thresholds). Based on the existing technologies, the wireless device may not determine an on-demand SSB as the candidate beams for the beam failure recovery procedure based on the on-demand SSB not being a periodic RS. This may lead frequent beam failure or may lead unsuccessful beam failure recovery for example in cases where the wireless device may identify beams associated with on-demands SSBs satisfying the conditions.

[0481] In existing technologies, the wireless device may determine the on-demand SSB as the candidate beam. The existing technologies do not address a behavior of the wireless device in cases where the on- demand SSBs become inactive (or deactivated). For example, if on-demand SSB is used for a candidate beam and a base station deactivates the on-demand SSB before the base station reconfigure / activate a new TCI state for the wireless device, the wireless device may experience another beam failure from the deactivated on-demand SSB. This may increase service interruption time and may reduce recovery efficiency.

[0482] In an example, a wireless device may indicate, to a base station, an SSB index associated with an on-demand SSB of a cell as a candidate beam for a beam failure recovery procedure of the cell. The cell may be a secondary cell or a primary cell. The wireless device may transmit a MAC CE comprising the SSB index or may use a RO mapping to the SSB index or may transmit one or more messages indicating the SSB index. The wireless device may receive a DCI scheduling an uplink transmission associated with the MAC CE or the one or more messages, for example to complete the beam failure recovery procedure of the cell. The wireless device may, based on the DCI, expect that the on-demand SSB would be transmitted and would be maintained as active at least until the wireless device receives one or more second messages indicating activation of a new TCI state for the cell. For example, the new TCI state may be associated with a first RS that is different from the on-demand SSB. The first RS may not have or may have a QCL relationship with the on-demand SSB. The first RS may be transmitted via a second cell that is different from the cell. The wireless device may receive one or more DCIs via the secondary cell based on the on-demand SSB, where a CORESET, for the one or more DCIs, is associated with the on-demand SSB. The wireless device may receive one or more PDSCHs via the secondary cell based on the on- demand SSB, where a TCI state of the one or more PDSCHs is associated with the on-demand SSB.

[0483] FIG.24 illustrates an example as per an aspect of an embodiment of the present disclosure. In the example shown in FIG.24, a wireless device receives one or more RRC messages indicating / comprising configuration parameters of a serving cell (CC#1, or a cell) at a time T0. The configuration parameters mayDocket No.: 24-1227PCT indicate / comprise parameters for on-demand SSBs of the serving cell. The configuration parameters may also indicate / comprise parameters for random access resources (or ROs). In one example, the configuration parameters may indicate SSBs of the serving cell (e.g., Case 2 in FIG.20). This case is referred as a SSB cell case or a non-SSB-less cell case. In this case, the wireless device, based on the configuration parameters, may determine the ROs and mapping between a RO and a SSB index of the SSBs. The wireless device may determine first valid ROs based on the SSBs.

[0484] In another example, the configuration parameters may not indicate the SSBs of the serving cell (e.g., Case 1 in FIG.20). This case is referred as an SSB-less cell case. In this case, the wireless device may not determine a mapping between a RO and a SSB index in response to the configuration parameters not indicating the SSBs of the serving cell (e.g., the serving cell not comprising the SSBs) at the time T0.

[0485] In the example shown in FIG.24, the wireless device receives one or more messages (e.g., RRC, MAC-CE and / or DCI) (Msg #1) at a time T1. The one or more messages activate the on-demand SSBs of the serving cell. The wireless device may determine second valid ROs based on the activation of the on- demand SSBs (Option 1 in FIG.24). In case of the SSB cell (e.g., the serving cell comprises the SSBs), the second valid ROs may be different or same from or to the first valid ROs. In case of the SSB-less cell (e.g., the serving cell does not comprise the SSBs), the second valid ROs is a non-zero size set. This option is referred as ‘Option 1’ in FIG.24.

[0486] Alternatively, in a different example, the wireless device may maintain the first valid ROs from the time T0 (if the first valid ROs are determined at the time T0) even after the activation of the on-demand SSBs (Option 2 in FIG.24). In other words, the wireless device may not update the first valid ROs even after the activation of the on-demand SSBs. The wireless device may not consider on-demand SSBs in determining valid ROs. This option is referred as ‘Option 2’ in FIG.24.

[0487] For example, when Option 1 is adopted, the wireless device may determine / update the second valid ROs based on the ROs of the configuration parameters and on-demand SSBs. The wireless device may determine / update a mapping between a SSB index of the SSBs and / or the on-demand SSBs and a RO of the second valid ROs. In an example, the wireless device may determine the second valid ROs, in response to the first valid ROs not being determined (or being an empty set) or the serving cell being an SSB-less cell (i.e., Case 1 in FIG.20). The wireless device may not determine the second valid ROs, in response to the first valid ROs being determined (or not being an empty set) or the serving cell comprising / transmitting the SSBs.

[0488] In one example, when Option 1 is adopted, the wireless device may expect that the one or more messages received at the time T1 may be one or more RRC messages that activate the on-demand SSBs with the configuration of the on-demand SSBs. The on-demand SSBs that are activated may be referred as activated on-demand SSBs or active on-demand SSBs. For example, the Msg#1 may be comprised in theDocket No.: 24-1227PCT configuration parameters received at the time T0. Alternatively, in a different example, the wireless device may expect that the one or more messages may be one or more group-common DCIs or may be broadcasted. In another example, the wireless device may expect that the Msg #1 may be a SIB1 or comprise a ServingCellConfigCommon IE of the serving cell.

[0489] When Option 1 is adopted for the SSB-less cell, the wireless device may activate the first / second valid ROs in response to activating the on-demand SSBs (i.e., start utilizing the first / second valid ROs with respect to the on-demand SSBs). The wireless device may be configured to perform a random access procedure via the serving cell based on activating the first / second valid ROs (or the first / second valid ROs being active). The wireless device may not be expected to or not required to perform a random access procedure via the serving cell based on deactivating the firs / second valid ROs (or the first / second ROs being inactive). The wireless device may expect to receive or may be required to receive a PDCCH order to initiate / trigger a PRACH transmission via the serving cell in response to activating the valid ROs. When Option 1 is used, the wireless device may not be required to or expect to receive a PDCCH order before the time T1 or before the on-demand SSBs are activated, where the serving cell is an SSB-less cell.

[0490] In an example, Option 1 may be used by the wireless device for the serving cell in response to the serving cell being an SSB-less cell. The wireless device may apply / adopt Option 2 in response to the serving cell not being an SSB-less cell (or the serving cell comprising the SSBs). In another example, the wireless device may apply Option 1 in response to the serving cell not comprising a CD-SSB in a BWP of the serving cell. The wireless device may apply Option 2 in response to the serving cell comprising a CD- SSB in a BWP of the serving cell.

[0491] In Option 1, when the wireless device is not provided with one or more cell-specific TDD configurations (e.g., tdd-UL-DL-ConfigurationCommon) of the serving cell, the wireless device may determine a RO of the ROs as valid for an uplink carrier of the serving cell, if the RO does not precede an on-demand SSB in a slot comprising the RO and a time gap between the last symbol of the last on-demand SSB candidate and the first symbol of the RO is larger than a value (e.g., 2). The wireless device may determine an on-demand SSB candidate based on a ssb-PositionsInBurst of the on-demand SSBs (e.g., od-ssb-PositionsInBurst).

[0492] In Option 1, when the wireless device is provided with one or more cell-specific TDD configurations (e.g., tdd-UL-DL-ConfigurationCommon) of the serving cell, the wireless device may determine a RO of the ROs as valid for an uplink carrier of the serving cell, if the RO is within UL symbols or the RO does not precede an on-demand SSB in a slot comprising the RO and a time gap between the last symbol of the last on-demand SSB candidate and the first symbol of the RO is larger than a value (e.g., 2). The wireless device may determine an on-demand SSB candidate based on a ssb-PositionsInBurst of the on-demand SSBs (e.g., od-ssb-PositionsInBurst).Docket No.: 24-1227PCT

[0493] When the wireless device applies Option 1, the wireless device may determine third valid ROs when the on-demand SSBs are deactivated. The wireless device may determine the third valid ROs being empty in case the serving cell does not comprise the CD-SSB or the NCD-SSB. In case the third valid ROs being empty, the wireless device may deactivate the ROs and may not be required to or expect to receive a PDCCH order for a random access procedure via the serving cell once the on-demand SSBs are deactivated.

[0494] When Option 1 is used, the wireless device may prioritize the on-demand SSBs over one or more uplink signals / channels when the resources of the SSBs and the uplink signals / channels partially or fully overlap. For example, the wireless device may receive one or more TDD configurations (e.g., tdd-UL-DL- ConfigurationCommon, tdd-UL-DL-ConfigurationDedicated) for the serving cell. The one or more TDD configurations may indicate one or more symbols of an on-demand SSB of the on-demand SSBs as downlink or flexible, but not as uplink. In another example, the one or more TDD configurations may indicate one or more symbols of an active on-demand SSB of the on-demand SSBs as downlink or flexible, but not as uplink. The wireless device may receive a SFI indicating the one or more symbols as downlink or flexible (but not as uplink). For example, the wireless device receives a DCI (e.g., Msg #2) scheduling an uplink transmission (e.g., a PUSCH, a PRACH) at a time T2. In the example, the uplink transmission may overlap with the on-demand SSB in time or the uplink transmission may start before than a necessary time gap to switch from downlink reception to uplink transmission (e.g., RX-TX-switching latency) after receiving the on-demand SSB, the wireless device may drop the uplink transmission. For example, the wireless device may prioritize the uplink transmission over receiving the on-demand SSB in case the wireless device is not able to transmit the uplink transmission and receive the on-demand SSB during a time window (e.g., during RX-TX-switching latency plus a transmission duration of the uplink transmission).

[0495] In the example, exemplary timings of activating the on-demand SSBs and / or deactivating the on- demand SSBs are illustrated in FIGs.19-22.

[0496] When the wireless device adopts Option 2, the wireless device may not update / determine the second valid ROs of the ROs after activating the on-demand SSBs. For example, if the serving cell is the SSB-less cell and the serving cell does not comprise the CD-SSB or the NCD-SSB, the wireless device may not determine the first / second valid ROs regardless of whether the on-demand SSBs are activated or deactivated. The wireless device may not expect or may not be required to handle a PDCCH triggering a PRACH transmission via the serving cell in such a case.

[0497] When Option 2 is used, the wireless device may determine the first valid ROs (and / or the second ROs and / or the third valid ROs) based on one or more CD-SSBs of the serving cell if the serving cell comprise the CD-SSB. The wireless device may not consider the on-demand SSBs in determining the first valid ROs (and / or the second ROs and / or the third valid ROs). The wireless device may determine the firstDocket No.: 24-1227PCT valid ROs based only on CD-SSBs of the serving cell if present. Otherwise, the wireless device may determine the valid ROs being empty (e.g., none).

[0498] In one example, the wireless device receives the DCI (e.g., Msg #2) scheduling the uplink transmission at the time T2. The DCI may be a PDCCH order triggering a PRACH transmission. The wireless device may determine a RO that may overlap with an active on-demand SSB or an on-demand SSB of the on-demand SSBs. The wireless device may determine that a gap between a RO and an on- demand SSB is smaller than a Ngap symbols (e.g., 2 symbols). For example, a time gap between the last symbol of the on-demand SSB and the first symbol of the RO may be smaller than the Ngap. In the example, the wireless device may transmit the PRACH via the RO based on the RO being valid. In the example, the wireless device may drop / skip monitoring / measuring the on-demand SSB that overlaps with the RO or that occurs no earlier than the Ngap symbols from the RO that is valid. For example, the wireless device may prioritize one or more uplink resources / transmissions compared to receiving the on-demand SSBs. For example, the wireless device transmits the uplink transmission and drops measurement on the on-demand SSB that overlaps with the uplink transmission in time.

[0499] In an example, the wireless device may determine, whether to apply Option 1 or Option 2 for determining the second valid ROs in response to the activated on-demand SSBs at the time T1, based on one or more second RRC messages. In an example, the one or more second RRC messages may comprise a parameter indicating whether to select Option 1 or Option 2 for the on-demand SSBs. For example, if the one or more second RRC messages indicate to apply Option 1, the wireless device may determine the second valid ROs based on the activated on-demand SSBs. If the one or more second RRC messages indicate to apply Option 2, the wireless device may not determine the second valid ROs and maintain the first valid ROs (i.e., the ROs determined at the time T0).

[0500] In an example implementation, the one or more second RRC messages may comprise a parameter indicating Option 1 or Option 2 (or enable to consider on-demand SSBs for valid RO determination or not).

[0501] In another example to determine Option 1 or Option2, the one or more second RRC messages may indicate that the serving cell comprises the CD-SSB (i.e., indicating that the serving cell supports the CD-SSB). In such case, the wireless device may determine to apply Option 2. If the one or more second RRC messages indicate that the serving cell does not comprise the CD-SSB (or the NCD-SSB), the wireless device may determine to apply Option 1. Alternatively, in a different example, if the serving cell comprises the CD-SSB (nor the NCD-SSB), the wireless device may determine to apply Option 1. Otherwise (e.g., no CD-SSB or NCD-SSB on the serving cell), the wireless device may not expect to transmit a PRACH via the serving cell, and thus may not determine the second valid ROs / valid ROs and may apply Option 2.Docket No.: 24-1227PCT

[0502] In an example, the one or more second RRC messages may indicate the on-demand SSBs associated with RMSIs (SIB1s). An on-demand SSB of the on-demand SSBs may comprise scheduling information to acquire a SIB1 of the serving cell. The on-demand SSB associated with RMSI or the on- demand SSB comprising scheduling information to acquire SIB1 (or indicating a CORESET#0) may be referred as a CD-OD-SSB (or OD-CD-SSB). An on-demand SSB without associated with RMSI may be referred as on-demand SSB, OD-SSB, NCD-OD-SSB or OD-NCD-SSB. In this example, the wireless device may apply Option 1 based on the on-demand SSB being the CD-OD-SSB or based on / in response to the on-demand SSB comprising scheduling information to acquire the SIB1 of the serving cell. Otherwise, the wireless device may apply Option 2.

[0503] Alternatively, in a different example, the wireless device may apply Option 2 for the on-demand SSBs that indicate scheduling information of the SIB1 (or CD-OD-SSB). In other words, the on-demand SSBs are CD-SSBs but not periodic. On-demand SSBs that are CD-SSBs may be referred as CD-OD- SSB. Regardless of whether an on-demand SSB comprises scheduling information for receiving the SIB1 or not (e.g., the on-demand SSB being associated with the RMSI or not), the wireless device may not update / determine the second valid ROs based on the activated on-demand SSBs (i.e., Option 2). In an example, on-demand SSBs may be transmitted in the same frequency as the frequency in which CD-SSBs of the serving cell (e.g., AbsoluteFrequencySSB of the on-demand SSBs is same as the CD-SSBs) are transmitted. In the example, the on-demand SSBs may not be associated with RMSIs (e.g., non-cell defining on-demand SSBs, NCD-OD-SSBs). For a duration (e.g., 40 msec) where one or more PBCHs with different RVs are transmitted for a single MIB transmission, the wireless device may assume / consider that one or more SSBs carrying the one or more PBCHs are either all (periodic) CD-SSBs or on-demand SSBs. The wireless device may not expect that the one or more SSBs during the duration comprise both a CD- SSB and an on-demand SSB. The wireless device may not be required to handle different content of MIB during the duration that is a decoding window of a MIB message.

[0504] Alternatively, in a different example, the wireless device may apply Option 1 in response to the on- demand SSB is a semi-periodic SSB (or a first type on-demand SSB or type1-od-SSB). The wireless device may apply Option 2 in response to the on-demand SSB is a non-semi-periodic SSB (or a second type on-demand SSB or type2-od-SSB).

[0505] In an example, the wireless device may determine the valid ROs based on the periodicity of P1 shown in Option 4 of FIG.22 regardless of the on-demand SSBs being activated or deactivated. For example, if the on-demand SSBs are associated with SIB1 (e.g., the wireless device may use the on- demand SSBs to acquire SIB1 or on-demand SSBs are CD-OD-SSBs), the wireless device may determine a periodicity with the on-demand SSBs, and may determine the valid ROs based on the on-demand SSBs (e.g., the periodicity of on-demands SSBs). The on-demand SSBs may be inactive or active. In theDocket No.: 24-1227PCT example, the wireless device may receive configurations of the on-demand SSBs via SIB1 and / or ServingCellConfigCommon. In another example, the wireless device may determine the valid ROs based on the P1 and P2 in shown in Option 4 of FIG.22 (e.g., based on a smaller / larger value between P1 and P2).

[0506] In an example, the configuration parameters may activate the on-demand SSBs and may indicate one or more parameters to indicate / configure the serving cell, of the on-demand SSBs, to the wireless device at a same time. The wireless device may determine the valid ROs based on cell defining SSBs that are not on-demand SSBs. For example, as shown in Option 4 of FIG.22, between the time A and the time B, additional on-demand SSBs are transmitted to decrease periodicity (P1) between two SSBs. In such example, the cell defining SSBs that are not on-demand SSBs may be determined based on a second periodicity (P2). The on-demand SSBs may be determined based on the decreased periodicity and the second periodicity (e.g., only additional SSBs excluding periodic SSBs based on the second periodicity). In an example, the wireless device may determine the valid ROs based on (periodic) cell-defining SSBs without accounting / considering on-demand cell-defining SSBs. In an example, the (periodic) cell defining SSBs may be determined based on a periodicity of a SSB burst in ssb-periodicityServingCell or ssb- periodicity in a ServingCellConfigCommon.

[0507] In an example, a first set of random access resources or a first set of ROs may be configured to be mapped to SSBs of the serving cell. A second set of random access resources or a second set of ROs may be configured to be mapped to on-demand SSBs of the serving cell. For the first set of ROs and the second set of ROs, different mapping parameters and / or parameters to determine the first set of ROs and the second set of ROs (e.g., ssb-perRACH-Occasion) may be configured respectively.

[0508] In an example, a wireless device receives one or more RRC messages indicating / comprising configuration parameters of a serving cell. The configuration parameters may indicate / comprise parameters for on-demand SSBs of the serving cell. The configuration parameters may also indicate / comprise parameters for random access resources (or ROs) via the serving cell. The configuration parameters may optionally indicate SSBs of the serving cell. The wireless device may receive a DCI format scheduling an uplink transmission. The wireless device may not transmit (e.g., drop, skip) the uplink transmission (e.g., a PUSCH, a PUCCH, a PRACH, a SRS), via the serving cell, in a slot in response to the uplink transmission overlapping, in time, with a SSB of the serving cell. In the example, the SSB is the CD-SSB of the serving cell. The SSB may be the NCD-SSB of an active downlink BWP of the serving cell. In this example, the wireless device may drop the uplink transmission. The wireless device may determine a set of symbols, that comprises one or more symbols overlapping with time locations of transmitted SSB(s), of the serving cell based on a ssb-PositionsInBurst in SIB1 or by ssb-PositionsInBurst in ServingCellConfigCommon. For example, a symbol of the set of symbols may comprise / is configured with a signal of a transmitted SSBDocket No.: 24-1227PCT based on the ssb-PositionsInBurst (e.g., in FIG.17, symbol#2-#5 are comprised in the set of symbols of the slot#0, as there is a SSB transmitted during symbol#2-#5, and symbol#6-#7 are not comprised in the set of symbols of the slot#0 as symbols#6-#7 are not overlapping with a candidate SSB time location(s). Symbol #0-#7 in the slot #2 are not comprised in the set of symbols of the slot#2, as a candidate SSB on the slot #2 is not transmitted, and symbol #8-#11 are comprised in the set of symbols of the slot#2).

[0509] For example, the ssb-PositionsInBurst may be applied for one or more CD-SSBs of the serving cell and / or one or more NCD-SSBs of the active downlink BWP of the serving cell.

[0510] The wireless device may not transmit (e.g., drop, skip) an uplink transmission (e.g., a PUSCH, a PUCCH, a PRACH), via the serving cell, in a slot in response to the uplink transmission overlapping, in time, with any symbol from the set of symbols. The wireless device may not transmit SRS in the set of symbols of the slot. The wireless device may not expect the set of symbols of the slot to be indicated as uplink by the tdd-UL-DLConfigurationCommon or tdd-UL-DL-ConfigurationDedicated, when provided to the wireless device.

[0511] In an example, the wireless device may transmit (e.g., drop, skip) an uplink transmission (e.g., a PUSCH, a PUCCH, a PRACH, a SRS), via the serving cell, in a slot, where the uplink transmission overlaps, in time, with an on-demand SSB of the serving cell and does not overlap with a SSB of the serving cell. In the example, the SSB is the CD-SSB of the serving cell. The SSB may be the NCD-SSB of an active downlink BWP of the serving cell. The wireless device may drop / skip measuring the on-demand SSB in response to transmitting the uplink transmission.

[0512] In an example, the wireless device may determine a second set of symbols in a slot for one or more on-demand SSBs of the serving cell based on i) ...

Claims

Docket No.: 24-1227PCT CLAIMS 1. A method comprising: receiving, by a wireless device, one or more configuration parameters of a cell, wherein the one or more configuration parameters indicate: configuration for on-demand synchronization signal blocks (OD-SSBs) of the cell, wherein: transmission of the OD-SSBs is triggered based on one or more downlink control commands; one or more first OD-SSBs of the OD-SSBs are transmitted based on a first periodicity; and one or more second OD-SSBs of the OD-SSBs are transmitted based on a second periodicity; and a plurality of physical random access channel (PRACH) occasions of the cell; determining a PRACH occasion, in the plurality of PRACH occasions, as valid based on: a first symbol of the PRACH occasion starting after a first gap from a last symbol of an OD- SSB transmission; the first periodicity; and the second periodicity; and transmitting a preamble via the PRACH occasion.

2. A method comprising transmitting, by a wireless device, a preamble via a physical random access channel (PRACH) occasion, wherein the PRACH occasion is determined based on: a first periodicity, wherein one or more first on-demand synchronization signal blocks (OD-SSBs) are transmitted based on the first periodicity; and a second periodicity, wherein one or more second OD-SSBs are transmitted based on the second periodicity.

3. The method of claim 2, comprising determining the PRACH occasion as valid based on the first periodicity and the second periodicity.

4. The method of claim 3, wherein the PRACH occasion is determined as valid further based on a first symbol of the PRACH occasion starting after a first gap from a last symbol of an OD-SSB transmission.

5. The method of any one of claims 2-4, comprising receiving, by the wireless device, one or more configuration parameters of a cell, wherein the one or more configuration parameters indicate configuration for OD-SSBs of the cell.

6. The method of claim 5, wherein: transmission of the OD-SSBs is triggered based on one or more downlink control commands; the one or more first OD-SSBs are included in the OD-SSBs; andDocket No.: 24-1227PCT the one or more second OD-SSBs are included in the OD-SSBs.

7. The method of claim 5 or 6, wherein: the one or more configuration parameters indicate a plurality of PRACH occasions of the cell; and the PRACH occasion is included in the plurality of PRACH occasions.

8. The method of any one of claims 4-7, wherein: the first gap is a minimum number of symbols required switching between a downlink reception and an uplink transmission; and the first gap is determined based on a subcarrier spacing of an uplink carrier of the cell.

9. The method of claim 8, wherein the PRACH occasion is determined as valid for the uplink carrier of the cell.

10. The method of any one of claims 2-9, wherein the PRACH occasion is determined based on a smaller one of the first periodicity and the second periodicity.

11. The method of any one of claims 4-10, wherein: the OD-SSB transmission is a first OD-SSB transmission; and the method comprises determining a second PRACH occasion, of the plurality of PRACH occasions, as invalid, based on a second symbol of the second PRACH occasion starting before the first gap from a last symbol of a second OD-SSB transmission.

12. The method of claim 11, further comprising receiving a downlink control information (DCI) format scheduling an uplink transmission during a third symbol overlapping with the first OD-SSB transmission.

13. The method of claim 12, further comprising transmitting the uplink transmission based on the first OD-SSB transmission being inactive.

14. The method of claim 12 or 13, further comprising skipping measuring the first OD-SSB transmission based on the first OD-SSB transmission being inactive.

15. The method of claim 11, further comprising determining one or more symbols, overlapping with the first OD- SSB transmission, as downlink symbols.

16. The method of claim 15, further comprising dropping the uplink transmission based on the uplink transmission overlapping with the downlink symbols.

17. The method of any one of claims 2-16, wherein the cell is not configured with a periodic SSB transmission.

18. The method of any one of claims 7-17, further comprising determining to use the plurality of PRACH occasions, based on the OD-SSBs, of the cell, being activated.

19. The method of any one of claims 7-17, further comprising skipping transmitting one or more preambles via the plurality of PRACH occasions after the OD-SSBs, of the cell, being deactivated.

20. The method of any one of claims 2-19, further comprising determining a physical uplink shared channel (PUSCH) occasion, of a plurality of PUSCH occasions, as valid based on:Docket No.: 24-1227PCT a third symbol of the PUSCH occasion starting after a second gap from a last symbol of a second OD- SSB transmission; the first periodicity; and the second periodicity.

21. The method of claim 20, further comprising transmitting an uplink transmission via the PUSCH occasion of a plurality of PUSCH occasions.

22. The method of claim 21, wherein the uplink transmission is a Msg A PUSCH.

23. The method of any one of claims 20-22, comprising receiving one or more radio resource control (RRC) messages indicating the plurality of PUSCH occasions.

24. A method comprising: receiving, by a wireless device, a plurality of configuration parameters of a secondary cell, wherein: the plurality of configuration parameters comprises one or more parameters indicating a candidate beam associated with a first on-demand synchronization signal block (SSB) with a first SSB index; and the first on-demand SSB is configured to be activated or deactivated via a downlink control command; and performing a layer 1 reference signal received power (L1-RSRP) measurement on the first on-demand SSB, based on: the first on-demand SSB being activated; and whether an active downlink bandwidth part (BWP) of the secondary cell comprises a second SSB that is configured to be transmitted periodically via the secondary cell; and transmitting, for a beam failure recovery of the secondary cell and based on the L1-RSRP measurement, an uplink signal comprising the first SSB index indicating the candidate beam.

25. A method comprising performing, by a wireless device, a layer 1 reference signal received power (L1-RSRP) measurement on a first on-demand synchronization signal block (SSB) or a second SSB that is configured to be transmitted periodically via a cell, based on: whether the first on-demand SSB is activated; and whether an active downlink bandwidth part (BWP) of the cell comprises the second SSB.

26. The method of claim 25, wherein the L1-RSRP measurement on the first on-demand SSB is performed based on: the first on-demand SSB being activated; and whether the active downlink BWP of the cell comprises the second SSB.

27. The method of claim 25 or 26, comprising receiving, by the wireless device, a plurality of configuration parameters of the cell, wherein:Docket No.: 24-1227PCT the plurality of configuration parameters comprises one or more parameters indicating a candidate beam associated with the first on-demand SSB with a first SSB index; and the first on-demand SSB is configured to be activated or deactivated via a downlink control command.

28. The method of claim 27, comprising transmitting, based on the L1-RSRP measurement, an uplink signal comprising the first SSB index indicating the candidate beam.

29. The method of any one of claims 25-28, wherein the uplink signal is transmitted for a beam failure recovery of the cell.

30. The method of any one of claims 25-29, wherein the cell is a secondary cell.

31. The method of any one of claims 25-30, wherein the L1-RSRP on the first on-demand SSB is performed based on: the first on-demand SSB being activated; and the active BWP of the cell not comprising the second SSB.

32. The method of any one of claims 25-30, wherein the L1-RSRP on the first on-demand SSB is performed based on: the first on-demand SSB being activated; and the active BWP of the cell comprising the second SSB.

33. The method of any one of claims 25-30, wherein the L1-RSRP on the second SSB is performed based on quasi-collocated (QCL) properties of the first on-demand SSB and QCL properties of the second SSB being equal.

34. The method of any one of claims 25-33, wherein the first SSB index of the first on-demand SSB is equal to an SSB index of the second SSB.

35. The method of any one of claims 27-34, further comprising determining the first on-demand SSB being active during the cell being activated, based on the candidate beam being associated with the first on- demand SSB.

36. The method of any one of claims 28-35, wherein the uplink signal comprises a medium access control control element (MAC CE) comprising the first SSB index.

37. The method of any one of claims 27-36, further comprising applying the candidate beam, based on the uplink signal, for communicating via the cell.

38. A method comprising: receiving, by a wireless device, a downlink control command indicating switching, for a secondary cell, from first on-demand synchronization signal block (OD-SSB) transmissions to second OD-SSB transmissions; andDocket No.: 24-1227PCT starting to receive the second OD-SSB transmissions after a time gap from the reception of the downlink control command, wherein the time gap is bases on an activation delay of the second OD-SSB transmissions and a deactivation delay of the first OD-SSB transmissions.

39. The method of claim 38, further comprising starting to apply a set of random access resources (ROs) based on the second OD-SSB transmissions occurring at a reference time after the activation delay of the second OD-SSB transmissions.

40. The method of claim 39, further comprising receiving configuration parameters, for the secondary cell, indicating: a plurality of on-demand synchronization signal block (OD-SSB) configurations comprising a first OD- SSB configuration and a second OD-SSB configuration; the first OD-SSB configuration indicating a first list of SSB indexes transmitted on a first OD-SSB burst of the first OD-SSB transmissions based on the first OD-SSB configuration; and the second OD-SSB configuration indicating a second list of SSB indexes transmitted on a second OD- SSB burst of second OD-SSB transmissions based on the second OD-SSB configuration, wherein the second list of SSB indexes is different from the first list of SSB indexes; and the set of ROs.

41. The method of any one of claims 38-40, further comprising receiving a first downlink control command indicating an activation of the first OD-SSB transmissions while the secondary cell is: not activated with any OD-SSB transmission; or deactivated.

42. The method of claim 41, further comprising starting to receive the first OD-SSB transmissions after a first activation delay after the reception of the first downlink control command.

43. The method of any one of claims 38-42, wherein: the downlink control command is a second downlink control command; and the second downlink control command is received while the first OD-SSB transmissions are active.

44. The method of claim 43, wherein the second downlink control command indicates an activation of the second OD-SSB transmissions.

45. The method of claim 43 or 44, wherein the indication of switching from the first OD-SSB transmissions to second OD-SSB transmissions is an indication of activating the second OD-SSB transmissions and deactivating the first OD-SSB transmissions.

46. The method of claim 43 or 44, wherein the second downlink command indicates the switching from the first OD-SSB transmissions to the second OD-SSB transmissions based on the first OD-SSB transmissions being active and the second downlink control command indicating the activation of the second OD-SSB transmissions.Docket No.: 24-1227PCT 47. The method of any one of claims 38-46, wherein: the time gap is determined as a larger value between a deactivation delay and an activation delay; the deactivation delay is for deactivating the first OD-SSB transmissions; and the activation delay is for activating the second OD-SSB transmissions.

48. The method of claim 47, wherein: the time gap starts after a time duration after the reception of the second downlink control command; and length of the time duration is length of the deactivation delay 49. 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 1-48.

50. A non-transitory computer-readable medium comprising instructions that, when executed by one or more processors, cause the one or more processors to perform the method of any one of claims 1-48.

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