Timing advance group(s) management

Abstract

A method is provided. The method comprises transmitting, by a wireless device, one or more uplink transmissions, using a transmit timing which is based on a reference cell. The reference cell is selected based on whether a first cell is configured with one or more on-demand synchronization signal blocks (SSBs).

Description

Docket No.: 24-1240PCTTITLETiming Advance Group(s) ManagementCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 714,652 , filed October 31 , 2024, which is hereby incorporated by reference in its entirety.BRIEF DESCRIPTION OF THE DRAWINGS

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

[0003] FIG. 1A and FIG. 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 configuration of an NR frame into which OFDM symbols are grouped.

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

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

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

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

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

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

[0017] FIG. 12A and FIG. 12B respectively illustrate examples of three downlink and uplink beam management procedures.Docket No.: 24-1240PCT

[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. 24A illustrates an aspect of an example embodiment according to the present disclosure.

[0031] FIG. 24B illustrates an aspect of an example embodiment according to the present disclosure.

[0032] FIG. 25 illustrates an aspect of an example embodiment according to the present disclosure

[0033] FIG. 26 illustrates an aspect of an example embodiment according to the present disclosure.

[0034] FIG. 27 illustrates an aspect of an example embodiment according to the present disclosure.

[0035] FIG. 28 illustrates an aspect of an example embodiment according to the present disclosure.

[0036] FIG. 29A illustrates an aspect of an example embodiment according to the present disclosure.

[0037] FIG. 29B illustrates an aspect of an example embodiment according to the present disclosure.

[0038] FIG. 29C illustrates an aspect of an example embodiment according to the present disclosure.

[0039] FIG. 30 illustrates an aspect of an example embodiment according to the present disclosure.

[0040] FIG. 31 illustrates an aspect of an example embodiment according to the present disclosure.

[0041] FIG. 32 illustrates an aspect of an example embodiment according to the present disclosure

[0042] FIG. 33 illustrates an aspect of an example embodiment according to the present disclosure.DETAILED DESCRIPTION

[0043] 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 beDocket No.: 24-1240PCT apparent to one skilled in the relevant art how to implement alternative embodiments. The present embodiments should not be limited by any of the described exemplary embodiments. The embodiments of the present disclosure will be described with reference to the accompanying drawings. Limitations, features, and / or elements from the disclosed example embodiments may be combined to create further embodiments within the scope of the disclosure. Any figures which highlight the functionality and advantages, are presented for example purposes only. The disclosed architecture is sufficiently flexible and configurable, such that it may be utilized in ways other than that shown. For example, the actions listed in any flowchart may be re-ordered or only optionally used in some embodiments.

[0044] 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.

[0045] 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.

[0046] 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 unenumeratedDocket No.: 24-1240PCT 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.

[0047] 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 = {cell 1 , cell2} are: {celH }, {cell2}, and {celH , cell2}. The phrase “based on” (or equally “based at least on") is indicative that the phrase following the term “based on” is an example of one of a multitude of suitable possibilities that may, or may not, be employed to one or more of the various embodiments. The phrase “in response to” (or equally “in response at least to”) is indicative that the phrase following the phrase “in response to" is an example of one of a multitude of suitable possibilities that may, or may not, be employed to one or more of the various embodiments. The phrase “depending on” (or equally “depending at least to”) is indicative that the phrase following the phrase “depending on” is an example of one of a multitude of suitable possibilities that may, or may not, be employed to one or more of the various embodiments. The phrase “employing / using” (or equally “employing / using at least”) is indicative that the phrase following 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.

[0048] 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.

[0049] In this disclosure, parameters (or equally called, fields, or Information elements: IBs) 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.Docket No.: 24-1240PCT

[0050] Many features presented are described as being optional through the use of "may” or the use of parentheses. For the sake of brevity and legibility, the present disclosure does not explicitly recite each and every permutation that may be obtained by choosing from the set of optional features. The present disclosure is to be interpreted as explicitly disclosing all such permutations. For example, a system described as having three optional features may be embodied in seven ways, namely with just one of the three possible features, with any two of the three possible features or with three of the three possible features.

[0051] 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.

[0052] FIG. 1 A illustrates an example of a mobile communication network 100 in which embodiments of the present disclosure may be implemented. The mobile communication network 100 may be, for example, a public land mobile network (PLMN) run by a network operator. As illustrated in FIG. 1A, the mobile communication network 100 includes a core network (CN) 102, a radio access network (RAN) 104, and a wireless device 106.

[0053] 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.Docket No.: 24-1240PCT

[0054] The RAN 104 may connect the CN 102 to the wireless device 106 through radio communications over an air interface. As part of the radio communications, the RAN 104 may provide scheduling, radio resource management, and retransmission protocols. The communication direction from the RAN 104 to the wireless device 106 over the air interface is known as the downlink and the communication direction from the wireless device 106 to the RAN 104 over the air interface is known as the uplink. Downlink transmissions may be separated from uplink transmissions using frequency division duplexing (FDD), timedivision duplexing (TDD), and / or some combination of the two duplexing techniques.

[0055] The term wireless device may be used throughout this disclosure to refer to and encompass any mobile device or fixed (non-mobile) device for which wireless communication is needed or usable. For example, a wireless device may be a telephone, smart phone, tablet, computer, laptop, sensor, meter, wearable device, Internet of Things (loT) device, vehicle roadside unit (RSU), relay node, automobile, and / or any combination thereof. The term wireless device encompasses other terminology, including user equipment (UE), user terminal (UT), access terminal (AT), mobile station, handset, wireless transmit and receive unit (WTRU), and / or wireless communication device.

[0056] 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).

[0057] 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.

[0058] 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 repeaterDocket No.: 24-1240PCT or relay node used to extend the coverage area of a donor node. A baseband processing unit coupled to RRHs may be part of a centralized or cloud RAN architecture, where the baseband processing unit may be either centralized in a pool of baseband processing units or virtualized. A repeater node may amplify and rebroadcast a radio signal received from a donor node. A relay node may perform the same / similar functions as a repeater node but may decode the radio signal received from the donor node to remove noise before amplifying and rebroadcasting the radio signal.

[0059] 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.

[0060] 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.

[0061] FIG. 1 B illustrates another example mobile communication network 150 in which embodiments of the present disclosure may be implemented. Mobile communication network 150 may be, for example, a PLMN run by a network operator. As illustrated in FIG. 1 B, mobile communication network 150 includes a 5G core network (5G-CN) 152, an NG-RAN 154, and UEs 156A and 156B (collectively UEs 156). These components may be implemented and operate in the same or similar manner as corresponding components described with respect to FIG. 1 A.

[0062] 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-CNDocket No.: 24-1240PCT152 may set up end-to-end connections between the UEs 156 and the one or more DNs, authenticate the UEs 156, and provide charging functionality. Compared to the CN of a 3GPP 4G network, the basis of the 5G-CN 152 may be a service-based architecture. This means that the architecture of the nodes making up the 5G-CN 152 may be defined as network functions that offer services via interfaces to other network functions. The network functions of the 5G-CN 152 may be implemented in several ways, including as network elements on dedicated or shared hardware, as software instances running on dedicated or shared hardware, or as virtualized functions instantiated on a platform (e.g., a cloud-based platform).

[0063] As illustrated in FIG. 1 B, the 5G-CN 152 includes an Access and Mobility Management Function (AMF) 158A and a User Plane Function (UPF) 158B, which are shown as one component AMF / UPF 158 in FIG 1 B for ease of illustration. The UPF 158B may serve as a gateway between the NG-RAN 154 and the one or more DNs. The UPF 158B may perform functions such as packet routing and forwarding, packet inspection and user plane policy rule enforcement, traffic usage reporting, uplink classification to support routing of traffic flows to the one or more DNs, quality of service (QoS) handling for the user plane (e.g., packet filtering, gating, uplink / downlink rate enforcement, and uplink traffic verification), downlink packet buffering, and downlink data notification triggering. The UPF 158B may serve as an anchor point for intra- / inter-Radio Access Technology (RAT) mobility, an external protocol (or packet) data unit (PDU) session point of interconnect to the one or more DNs, and / or a branching point to support a multi-homed 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

[0064] 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.

[0065] The 5G-CN 152 may include one or more additional network functions that are not shown in FIG 1 B for the sake of clarity. For example, the 5G-CN 152 may include one or more of a Session Management Function (SMF), an NR Repository Function (NRF), a Policy Control Function (PCF), a Network Exposure Function (NEF), a Unified Data Management (UDM), an Application Function (AF), and / or an Authentication Server Function (AUSF).

[0066] 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 160BDocket No.: 24-1240PCT(collectively gNBs 160) and / or one or more ng-eNBs, illustrated as ng-eNB 162A and ng-eNB 162B (collectively ng-eNBs 162). The gNBs 160 and ng-eNBs 162 may be more generically referred to as base stations. The gNBs 160 and ng-eNBs 162 may include one or more sets of antennas for communicating with the UEs 156 over an air interface. For example, one or more of the gNBs 160 and / or one or more of the ng-eNBs 162 may include three sets of antennas to respectively control three cells (or sectors). Together, the cells of the gNBs 160 and the ng-eNBs 162 may provide radio coverage to the UEs 156 over a wide geographic area to support UE mobility.

[0067] As shown in FIG. 1 B, the gNBs 160 and / or the ng-eNBs 162 may be connected to the 5G-CN 152 by means of an NG interface and to other base stations by an Xn interface. The NG and Xn interfaces may be established using direct physical connections and / or indirect connections over an underlying transport network, such as an internet protocol (IP) transport network. The gNBs 160 and / or the ng-eNBs 162 may be connected to the UEs 156 by means of a Uu interface. For example, as illustrated in FIG. 1 B, gNB 160A may be connected to the UE 156A by means of a Uu interface. The NG, Xn, and Uu interfaces are associated with a protocol stack. The protocol stacks associated with the interfaces may be used by the network elements in FIG. 1 B to exchange data and signaling messages and may include two planes: a user plane and a control plane. The user plane may handle data of interest to a user. The control plane may handle signaling messages of interest to the network elements.

[0068] 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.

[0069] 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.Docket No.: 24-1240PCT

[0070] The 5G-CN 152 was described as being configured to handle NR and 4G radio accesses. It will be appreciated by one of ordinary skill in the art that it may be possible for NR to connect to a 4G core network in a mode known as “non-standalone operation.” In non-standalone operation, a 4G core network is used to provide (or at least support) control-plane functionality (e.g., initial access, mobility, and paging). Although only one AMF / UPF 158 is shown in FIG. 1 B, one gNB or ng-eNB may be connected to multiple AMF / UPF nodes to provide redundancy and / or to load share across the multiple AMF / UPF nodes.

[0071] As discussed, an interface (e.g., Uu, Xn, and NG interfaces) between the network elements in FIG. 1 B may be associated with a protocol stack that the network elements use to exchange data and signaling messages. A protocol stack may include two planes: a user plane and a control plane. The user plane may handle data of interest to a user, and the control plane may handle signaling messages of interest to the network elements.

[0072] FIG. 2A and FIG. 2B respectively illustrate examples of NR user plane and NR control plane protocol stacks for the Uu interface that lies between a UE 210 and a gNB 220. The protocol stacks illustrated in FIG. 2A and FIG. 2B may be the same or similar to those used for the Uu interface between, for example, the UE 156A and the gNB 160A shown in FIG. 1 B.

[0073] 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.

[0074] 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 indicatorDocket No.: 24-1240PCT(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.

[0075] The PDCPs 214 and 224 may perform header compression / decompression to reduce the amount of data that needs to be transmitted over the air interface, ciphering / deciphering to prevent unauthorized decoding of data transmitted over the air interface, and integrity protection (to ensure control messages originate from intended sources. The PDCPs 214 and 224 may perform retransmissions of undelivered packets, in-sequence delivery and reordering of packets, and removal of packets received in duplicate due to, for example, an intra-g NB handover. The PDCPs 214 and 224 may perform packet duplication to improve the likelihood of the packet being received and, at the receiver, remove any duplicate packets. Packet duplication may be useful for services that require high reliability.

[0076] 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.

[0077] 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.

[0078] 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,Docket No.: 24-1240PCT 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.

[0079] The PHYs 211 and 221 may perform mapping of transport channels to physical channels and digital and analog signal processing functions for sending and receiving information over the air interface. These digital and analog signal processing functions may include, for example, coding / decoding and modulation / demodulation. The PHYs 211 and 221 may perform multi-antenna mapping. As shown in FIG. 3, the PHYs 211 and 221 may provide one or more transport channels as a service to the MACs 212 and 222.

[0080] 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.

[0081] 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.

[0082] 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.

[0083] 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 fromDocket No.: 24-1240PCT 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.

[0084] 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) and at the end of a MAC PDU for uplink transmissions. MAC CEs may be used for in-band control signaling. Example MAC CEs include: scheduling-related MAC CEs, such as buffer status reports and power headroom reports; activation / deactivation MAC CEs, such as those for activation / deactivation of PDCP duplication detection, channel state information (CSI) reporting, sounding reference signal (SRS) transmission, and prior configured components; discontinuous reception (DRX) related MAC CEs; timing advance MAC CEs; and random access related MAC CEs. A MAC CE may be preceded by a MAC subheader with a similar format as described for MAC SDUs and may be identified with a reserved value in the LCID field that indicates the type of control information included in the MAC CE.

[0085] 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.

[0086] 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:

[0087] - 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;

[0088] - 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;

[0089] - a common control channel (CCCH) for carrying control messages together with random access;

[0090] - a dedicated control channel (DCCH) for carrying control messages to / from a specific the UE to configure the UE; andDocket No.: 24-1240PCT

[0091] - a dedicated traffic channel (DTCH) for carrying user data to / from a specific the UE.

[0092] 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:

[0093] - a paging channel (PCH) for carrying paging messages that originated from the PCCH;

[0094] - a broadcast channel (BCH) for carrying the MIB from the BCCH;

[0095] - a downlink shared channel (DL-SCH) for carrying downlink data and signaling messages, including the SIBs from the BCCH;

[0096] - an uplink shared channel (UL-SCH) for carrying uplink data and signaling messages; and

[0097] - a random access channel (RACH) for allowing a UE to contact the network without any prior scheduling.

[0098] 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:

[0099] - a physical broadcast channel (PBCH) for carrying the MIB from the BCH;

[0100] - 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;

[0101] -- 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;

[0102] - 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;

[0103] -- a physical uplink control channel (PUCCH) for carrying UCI, which may include HARQ acknowledgments, channel quality indicators (CQI), pre-coding matrix indicators (PM I), rank indicators (Rl), and scheduling requests (SR); and

[0104] - a physical random access channel (PRACH) for random access.

[0105] 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), soundingDocket No.: 24-1240PCT reference signals (SRS), and phase-tracking reference signals (PT-RS). These physical layer signals will be described in greater detail below.

[0106] FIG. 2B illustrates an example NR control plane protocol stack. As shown in FIG. 2B, the NR control plane protocol stack may use the same / similar first four protocol layers as the example NR user plane protocol stack. These four protocol layers include the PHYs 211 and 221 , the MACs 212 and 222, the RLCs 213 and 223, and the PDCPs 214 and 224. Instead of having the SDAPs 215 and 225 at the top of the stack as in the NR user plane protocol stack, the NR control plane stack has radio resource controls (RRCs) 216 and 226 and NAS protocols 217 and 237 at the top of the NR control plane protocol stack.

[0107] 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.

[0108] 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 controlplane and user-plane data into the same transport block (TB). The RRCs 216 and 226 may provide control plane functionality such as: broadcast of system information related to AS and NAS; paging initiated by the CN or the RAN; establishment, maintenance and release of an RRC connection between the UE 210 and the RAN; security functions including key management; establishment, configuration, maintenance and release of signaling radio bearers and data radio bearers; mobility functions; QoS management functions; the UE measurement reporting and control of the reporting; detection of and recovery from radio link failure (RLF); and / or NAS message transfer. As part of establishing an RRC connection, RRCs 216 and 226 may establish an RRC context, which may involve configuring parameters for communication between the UE 210 and the RAN .

[0109] FIG. 6 is an example diagram showing RRC state transitions of a UE. The UE may be the same or similar to the wireless device 106 depicted in FIG. 1A, the UE 210 depicted in FIG. 2A and FIG. 2B, or any other wireless device described in the present disclosure. As illustrated in FIG. 6, a UE may be in at least one of three RRC states: RRC connected 602 (e.g., RRC_CONNECTED), RRC idle 604 (e.g., RRC_I DLE), and RRC inactive 606 (e.g., RRCJNACTIVE).Docket No.: 24-1240PCT

[0110] In RRC connected 602, the UE has an established RRC context and may have at least one RRC connection with a base station. The base station may be similar to one of the one or more base stations included in the RAN 104 depicted in FIG. 1A, one of the gNBs 160 or ng-eNBs 162 depicted in FIG. 1 B, the gNB 220 depicted in FIG. 2A and FIG. 2B, or any other base station described in the present disclosure. The base station with which the UE is connected may have the RRC context for the UE. The RRC context, referred to as the UE context, may comprise parameters for communication between the UE and the base station. These parameters may include, for example: one or more AS contexts; one or more radio link configuration parameters; bearer configuration information (e.g., relating to a data radio bearer, signaling radio bearer, logical channel, QoS flow, and / or EDU 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.

[0111] 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.

[0112] 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.

[0113] 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 mobileDocket No.: 24-1240PCT communications network. The mobility management mechanism used in RRC idle 604 and RRC inactive 606 may allow the network to track the UE on a cell-group level so that the paging message may be broadcast over the cells of the cell group that the UE currently resides within instead of the entire mobile communication network. The mobility management mechanisms for RRC idle 604 and RRC inactive 606 track the UE on a cell-group level. They may do so using different granularities of grouping. For example, there may be three levels of cell-grouping granularity: individual cells; cells within a RAN area identified by a RAN area identifier (RAI); and cells within a group of RAN areas, referred to as a tracking area and identified by a tracking area identifier (TAI).

[0114] 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.

[0115] 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.

[0116] 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.

[0117] A gNB, such as gNBs 160 in FIG. 1 B, may be split into two parts: a central unit (gNB-CU), and one or more distributed units (gNB-DU). A gNB-CU may be coupled to one or more gNB-DUs using an F1 interface. The gNB-CU may comprise the RRC, the PDCP, and the SDAP. A gNB-DU may comprise the RLC, the MAC, and the PHY.

[0118] 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 timeDocket No.: 24-1240PCT domain. The IFFT block may take in F source symbols at a time, one from each of the F parallel symbol streams, and use each source symbol to modulate the amplitude and phase of one of F sinusoidal basis functions that correspond to the F orthogonal subcarriers. The output of the IFFT block may be F timedomain samples that represent the summation of the F orthogonal subcarriers. The F time-domain samples may form a single OFDM symbol. After some processing (e.g addition of a cyclic prefix) and up- conversion, an OFDM symbol provided by the IFFT block may be transmitted over the air interface on a carrier frequency. The F parallel symbol streams may be mixed using an FFT block before being processed by the IFFT block. This operation produces Discrete Fourier Transform (DFT)-precoded OFDM symbols and may be used by UEs in the uplink to reduce the peak to average power ratio (PAPR). Inverse processing may be performed on the OFDM symbol at a receiver using an FFT block to recover the data mapped to the source symbols.

[0119] 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.

[0120] 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 ps. For example, NR defines numerologies with the following subcarrier spacing / cyclic prefix duration combinations: 15 kHz / 4.7 ps; 30 kHz / 2.3 ps; 60 kHz / 1.2 ps; 120 kHz / 0.59 ps; and 240 kHz / 0.29 ps.

[0121] 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.Docket No.: 24-1240PCT

[0122] FIG. 8 illustrates an example configuration of a slot in the time and frequency domain for an NR carrier. The slot includes resource elements (REs) and resource blocks (RBs). An RE is the smallest physical resource in NR. An RE spans one OFDM symbol in the time domain by one subcarrier in the frequency domain as shown in FIG. 8. An RB spans twelve consecutive REs in the frequency domain as shown in FIG. 8. An NR carrier may be limited to a width of 275 RBs or 275x12 = 3300 subcarriers. Such a limitation, if used, may limit the NR carrier to 50, 100, 200, and 400 MHz for subcarrier spacings of 15, 30, 60, and 120 kHz, respectively, where the 400 MHz bandwidth may be set based on a 400 MHz per carrier bandwidth limit.

[0123] 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.

[0124] 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.

[0125] 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.

[0126] 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.

[0127] 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.Docket No.: 24-1240PCT

[0128] 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).

[0129] 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.

[0130] 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.

[0131] 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.

[0132] 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).

[0133] 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.Docket No.: 24-1240PCT

[0134] FIG. 9 illustrates an example of bandwidth adaptation using three configured BWPs for an NR carrier. A UE configured with the three BWPs may switch from one BWP to another BWP at a switching point. In the example illustrated in FIG. 9, the BWPs include: a BWP 902 with a bandwidth of 40 MHz and a subcarrier spacing of 15 kHz; a BWP 904 with a bandwidth of 10 MHz and a subcarrier spacing of 15 kHz; and a BWP 906 with a bandwidth of 20 MHz and a subcarrier spacing of 60 kHz. The BWP 902 may be an initial active BWP, and the BWP 904 may be a default BWP. The UE may switch between BWPs at switching points. In the example of FIG. 9, the UE may switch from the BWP 902 to the BWP 904 at a switching point 908. The switching at the switching point 908 may occur for any suitable reason, for example, in response to an expiry of a BWP inactivity timer (indicating switching to the default BWP) and / or in response to receiving a DCI indicating BWP 904 as the active BWP. The UE may switch at a switching point 910 from active BWP 904 to BWP 906 in response to receiving a DCI indicating BWP 906 as the active BWP. The UE may switch at a switching point 912 from active BWP 906 to BWP 904 in response to an expiry of a BWP inactivity timer and / or in response to receiving a DCI indicating BWP 904 as the active BWP. The UE may switch at a switching point 914 from active BWP 904 to BWP 902 in response to receiving a DCI indicating BWP 902 as the active BWP.

[0135] 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.

[0136] 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

[0137] 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).

[0138] 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 aDocket No.: 24-1240PCT 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.

[0139] When CA is used, one of the aggregated cells for a UE may be referred to as a primary cell (PCell). The PCell may be the serving cell that the UE initially connects to at RRC connection establishment, reestablishment, and / or handover. The PCell may provide the UE with NAS mobility information and the security input. UEs may have different PCells. In the downlink, the carrier corresponding to the PCell may be referred to as the downlink primary CC (DL PCC). In the uplink, the carrier corresponding to the PCell may be referred to as the uplink primary CC (UL PCC). The other aggregated cells for the UE may be referred to as secondary cells (SCells). In an example, the SCells may be configured after the PCell is configured for the UE For example, an SCell may be configured through an RRC Connection Reconfiguration procedure. In the downlink, the carrier corresponding to an SCell may be referred to as a downlink secondary CC (DL SCC). In the uplink, the carrier corresponding to the SCell may be referred to as the uplink secondary CC (UL SCC).

[0140] 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).

[0141] Downlink control information, such as scheduling assignments and scheduling grants, for a cell may be transmitted on the cell corresponding to the assignments and grants, which is known as selfscheduling. The DCI for the cell may be transmitted on another cell, which is known as cross-carrier scheduling. Uplink control information (e g., HARQ acknowledgments and channel state feedback, such as CQI, PMI, and / or Rl) for aggregated cells may be transmitted on the PUCCH of the PCell. For a larger number of aggregated downlink CCs, the PUCCH of the PCell may become overloaded. Cells may be divided into multiple PUCCH groups.

[0142] 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 informationDocket No.: 24-1240PCT(UCI) related to the downlink CCs of the PUCCH group 1010, shown as UC1 1031 , UC1 1032, and UCI 1033, may be transmitted in the uplink of the PCell 1021. Uplink control information (UCI) related to the downlink CCs of the PUCCH group 1050, shown as UCI 1071 , UC1 1072, and UCI 1073, may be transmitted in the uplink of the PSCell 1061. In an example, if the aggregated cells depicted in FIG. 10B were not divided into the PUCCH group 1010 and the PUCCH group 1050, a single uplink PCell to transmit UCI relating to the downlink CCs, and the PCell may become overloaded. By dividing transmissions of UCI between the PCell 1021 and the PSCell 1061 , overloading may be prevented.

[0143] 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.

[0144] 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.

[0145] 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.

[0146] 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 / PBCHDocket No.: 24-1240PCT 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.

[0147] The SS / PBCH block may span one or more OFDM symbols in the time domain (e.g., 4 OFDM symbols, as shown in the example of FIG. 11 A) and may span one or more subcarriers in the frequency domain (e.g., 240 contiguous subcarriers). The PSS, the SSS, and the PBCH may have a common center frequency. The PSS may be transmitted first and may span, for example, 1 OFDM symbol and 127 subcarriers. The SSS may be transmitted after the PSS (e.g., two symbols later) and may span 1 OFDM symbol and 127 subcarriers. The PBCH may be transmitted after the PSS (e.g., across the next 3 OFDM symbols) and may span 240 subcarriers.

[0148] 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.

[0149] 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.

[0150] 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 1Docket No.: 24-1240PCT(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.

[0151] The UE may assume that one or more SS / PBCH blocks transmitted with a same SS / PBCH block index are quasi co-located (QCLed) (e.g . , having the same / similar Doppler spread, Doppler shift, average gain, average delay, and / or spatial Rx parameters). The UE may not assume QCL for SS / PBCH block transmissions having different SS / PBCH block indices.

[0152] 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.

[0153] 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.

[0154] 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.

[0155] 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.

[0156] 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 transmitDocket No.: 24-1240PCT 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.

[0157] The CSI-RS configuration may comprise one or more parameters indicating, for example, up to 32 antenna ports. The UE may be configured to employ the same OFDM symbols for a downlink CSI-RS and a control resource set (CORESET) when the downlink CSI-RS and CORESET are spatially QCLed and resource elements associated with the downlink CSI-RS are outside of the physical resource blocks (PRBs) configured for the CORESET. The UE may be configured to employ the same OFDM symbols for downlink CSI-RS and SS / PBCH blocks when the downlink CSI-RS and SS / PBCH blocks are spatially QCLed and resource elements associated with the downlink CSI-RS are outside of PRBs configured for the SS / PBCH blocks.

[0158] 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.

[0159] 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).

[0160] 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.Docket No.: 24-1240PCT

[0161] Downlink PT-RS may be transmitted by a base station and used by a UE for phase-noise compensation. Whether a downlink PT-RS is present or not may depend on an RRC configuration. The presence and / or pattern of the downlink PT-RS may be configured on a UE-specific basis using a combination of RRC signaling and / or an association with one or more parameters employed for other purposes (e.g., modulation and coding scheme (MCS)), which may be indicated by DCI. When configured, a dynamic presence of a downlink PT-RS may be associated with one or more DCI parameters comprising at least MCS. An NR network may support a plurality of PT-RS densities defined in the time and / or frequency domains. When present, a frequency domain density may be associated with at least one configuration of a scheduled bandwidth. The UE may assume a same precoding for a DMRS port and a PT-RS port. A number of PT-RS ports may be fewer than a number of DMRS ports in a scheduled resource. Downlink PT-RS may be confined in the scheduled time / frequency duration for the UE. Downlink PT-RS may be transmitted on symbols to facilitate phase tracking at the receiver.

[0162] 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.

[0163] 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.

[0164] 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 mayDocket No.: 24-1240PCT 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.

[0165] SRS may be transmitted by a UE to a base station for channel state estimation to support uplink channel dependent scheduling and / or link adaptation. SRS transmitted by the UE may allow a base station to estimate an uplink channel state at one or more frequencies. A scheduler at the base station may employ the estimated uplink channel state to assign one or more resource blocks for an uplink PUSCH transmission from the UE. The base station may semi-statically configure the UE with one or more SRS resource sets. For an SRS resource set, the base station may configure the UE with one or more SRS resources. An SRS resource set applicability may be configured by a higher layer (e.g., RRC) parameter. For example, when a higher layer parameter indicates beam management, an SRS resource in an SRS resource set of the one or more SRS resource sets (e.g., with the same / similar time domain behavior, periodic, aperiodic, and / or the like) may be transmitted at a time instant (e.g., simultaneously). The UE may transmit one or more SRS resources in SRS resource sets. An NR network may support aperiodic, periodic and / or semi-persistent SRS transmissions. The UE may transmit SRS resources based on one or more trigger types, wherein the one or more trigger types may comprise higher layer signaling (e.g., RRC) and / or one or more DCI formats. In an example, at least one DCI format may be employed for the UE to select at least one of one or more configured SRS resource sets. An SRS trigger type 0 may refer to an 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.

[0166] 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.

[0167] 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 symbolDocket No.: 24-1240PCT 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.

[0168] Channels that use beamforming require beam management. Beam management may comprise beam measurement, beam selection, and beam indication. A beam may be associated with one or more reference signals. 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.

[0169] FIG. 11 B illustrates an example of channel state information reference signals (CSI-RSs) that are mapped in the time and frequency domains. A square shown in FIG. 11 B may span a resource block (RB) within a bandwidth of a cell. A base station may transmit one or more RRC messages comprising CSI-RS resource configuration parameters indicating one or more CSI-RSs. One or more of the following parameters may be configured by higher layer signaling (e.g., RRC and / or MAC signaling) for a CSI-RS resource configuration: a CSI-RS resource configuration identity, a number of CSI-RS ports, a CSI-RS configuration (e.g., symbol and resource element (RE) locations in a subframe), a CSI-RS subframe configuration (e.g., subframe location, offset, and periodicity in a radio frame), a CSI-RS power parameter, a CSI-RS sequence parameter, a code division multiplexing (CDM) type parameter, a frequency density, a transmission comb, quasi co-location (QCL) parameters (e.g., QCL-scramblingidentity, crs-portscount, mbsfn-subframeconfiglist, csi-rs-configZPid, qcl-csi-rs-configNZPid), and / or other radio resource parameters.

[0170] The three beams illustrated in FIG. 11 B may be configured for a UE in a UE-specific configuration. Three beams are illustrated in FIG. 11 B (beam #1 , beam #2, and beam #3), more or fewer beams may be configured. Beam #1 may be allocated with CSI-RS 1101 that may be transmitted in one or more subcarriers in an RB of a first symbol. Beam #2 may be allocated with CSI-RS 1102 that may be transmitted in one or more subcarriers in an RB of a second symbol. Beam #3 may be allocated with CSI- RS 1103 that may be transmitted in one or more subcarriers in an RB of a third symbol. By using frequency division multiplexing (EDM), 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.Docket No.: 24-1240PCT

[0171] CSI-RSs such as those illustrated in FIG 11 B (e.g., CSI-RS 1101 , 1102, 1103) may be transmitted by the base station and used by the UE for one or more measurements. For example, the UE may measure a reference signal received power (RSRP) of configured CSI-RS resources. The base station may configure the UE with a reporting configuration and the UE may report the RSRP measurements to a network (for example, via one or more base stations) based on the reporting configuration. In an example, the base station may determine, based on the reported measurement results, one or more transmission configuration indication (TCI) states comprising a number of reference signals. In an example, the base station may indicate one or more TCI states to the UE (e.g., via RRC signaling, a MAC CE, and / or a DCI). The UE may receive a downlink transmission with a receive (Rx) beam determined based on the one or more TCI states. In an example, the UE may or may not have a capability of beam correspondence. If the UE has the capability of beam correspondence, the UE may determine a spatial domain filter of a transmit (Tx) beam based on a spatial domain filter of the corresponding Rx beam. If the UE does not have the capability of beam correspondence, the UE may perform an uplink beam selection procedure to determine the spatial domain filter of the Tx beam. The UE may perform the uplink beam selection procedure based on one or more sounding reference signal (SRS) resources configured to the UE by the base station The base station may select and indicate uplink beams for the UE based on measurements of the one or more SRS resources transmitted by the UE.

[0172] 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 (Rl).

[0173] 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. ThisDocket No.: 24-1240PCT 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.

[0174] FIG. 12B illustrates examples of three uplink beam management procedures: U1 , U2, and U3. Procedure U1 may be used to enable a base station to perform a measurement on Tx beams of a UE, e.g., to support a selection of one or more UE Tx beams and / or base station Rx beams (shown as ovals in the top row and bottom row, respectively, of U1). Beamforming at the UE may include, e.g., a Tx beam sweep from a set of beams (shown in the bottom rows of U1 and U3 as ovals rotated in a clockwise direction indicated by the dashed arrow). Beamforming at the base station may include, e.g., an Rx beam sweep from a set of beams (shown, in the top rows of U1 and U2, as ovals rotated in a counterclockwise direction indicated by the dashed arrow). Procedure U2 may be used to enable the base station to adjust its Rx beam when the UE uses a fixed Tx beam. The UE and / or the base station may perform procedure U2 using a smaller set of beams than is used in procedure P1 , or using narrower beams than the beams used in procedure P1 . This may be referred to as beam refinement The UE may perform procedure U3 to adjust its Tx beam when the base station uses a fixed Rx beam.

[0175] 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).

[0176] 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.

[0177] A network (e.g., a gNB and / or an ng-eNB of a network) and / or the UE may initiate a random access procedure. A UE in an RRCJDLE state and / or an RRCJNACTIVE state may initiate the random access procedure to request a connection setup to a network. The UE may initiate the random accessDocket No.: 24-1240PCT 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.

[0178] FIG. 13A illustrates a four-step contention-based random access procedure. Prior to initiation of the procedure, a base station may transmit a configuration message 1310 to the UE. The procedure illustrated in FIG. 13A comprises transmission of four messages: a Msg 1 1311 , a Msg 2 1312, a Msg 3 1313, and a Msg 4 1314. The Msg 1 1311 may include and / or be referred to as a preamble (or a random access preamble). The Msg 2 1312 may include and / or be referred to as a random access response (RAR).

[0179] The configuration message 1310 may be transmitted, for example, using one or more RRC messages. The one or more RRC messages may indicate one or more random access channel (RACH) parameters to the UE. The one or more RACH parameters may comprise at least one of following: general parameters for one or more random access procedures (e.g., RACH-configGeneral)', cell-specific parameters (e.g., RACH-ConfigCommon) and / or dedicated parameters (e.g., RACH-configDedicated). The base station may broadcast or multicast the one or more RRC messages to one or more UEs. The one or more RRC messages may be UE-specific (e.g., dedicated RRC messages transmitted to a UE in an RRC_CONNECTED state and / or in an RRCJNACTIVE state). The UE may determine, based on the one or more RACH parameters, a time-frequency resource and / or an uplink transmit power for transmission of the Msg 1 1311 and / or the Msg 3 1313. Based on the one or more RACH parameters, the UE may determine a reception timing and a downlink channel for receiving the Msg 2 1312 and the Msg 4 1314.

[0180] The one or more RACH parameters provided in the configuration message 1310 may indicate one or more Physical RACH (PRACH) occasions available for transmission of the Msg 1 1311. The one or more PRACH occasions may be predefined. The one or more RACH parameters may indicate one or more available sets of one or more PRACH occasions (e.g., prach-Configlndex). 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.Docket No.: 24-1240PCT

[0181] The one or more RACH parameters provided in the configuration message 1310 may be used to determine an uplink transmit power of Msg 1 1311 and / or Msg 3 1313. For example, the one or more RACH parameters may indicate a reference power for a preamble transmission (e.g., a received target power and / or an initial power of the preamble transmission). There may be one or more power offsets indicated by the one or more RACH parameters. For example, the one or more RACH parameters may indicate: a power ramping step; a power offset between SSB and CSI-RS; a power offset between transmissions of the Msg 1 1311 and the Msg 3 1313; and / or a power offset value between preamble groups. The one or more RACH parameters may indicate one or more thresholds based on which the UE may determine at least one reference signal (e.g., an SSB and / or CSI-RS) and / or an uplink carrier (e.g., a normal uplink (NUL) carrier and / or a supplemental uplink (SUL) carrier).

[0182] The Msg 1 1311 may include one or more preamble transmissions (e.g., a preamble transmission and one or more preamble retransmissions). An RRC message may be used to configure one or more preamble groups (e.g., group A and / or group B). A preamble group may comprise one or more preambles. The UE may determine the preamble group based on a pathloss measurement and / or a size of the Msg 3 1313. The UE may measure an RSRP of one or more reference signals (e.g., SSBs and / or CSI-RSs) and determine at least one reference signal having an RSRP above an RSRP threshold (e.g., rsrp- ThresholdSSB and / or rsrp-ThresholdCSI-RS). The UE may select at least one preamble associated with the one or more reference signals and / or a selected preamble group, for example, if the association between the one or more preambles and the at least one reference signal is configured by an RRC message.

[0183] The UE may determine the preamble based on the one or more RACH parameters provided in the configuration message 1310. For example, the UE may determine the preamble based on a pathloss measurement, an RSRP measurement, and / or a size of the Msg 3 1313. As another example, the one or more RACH parameters may indicate: a preamble format; a maximum number of preamble transmissions; and / or one or more thresholds for determining one or more preamble groups (e.g., group A and group B). A base station may use the one or more RACH parameters to configure the UE with an association between one or more preambles and one or more reference signals (e.g., SSBs and / or CSI-RSs). If the association is configured, the UE may determine the preamble to include in Msg 1 1311 based on the association. The Msg 1 1311 may be transmitted to the base station via one or more PRACH occasions. The UE may use one or more reference signals (e.g., SSBs and / or CSI-RSs) for selection of the preamble and for determining of the PRACH occasion. One or more RACH parameters (e.g., ra-ssb-OccasionMsklndex and / or ra-OccasionList) may indicate an association between the PRACH occasions and the one or more reference signals.Docket No.: 24-1240PCT

[0184] The UE may perform a preamble retransmission if no response is received following a preamble transmission. The UE may increase an uplink transmit power for the preamble retransmission. The UE may select an initial preamble transmit power based on a pathloss measurement and / or a target received preamble power configured by the network. The UE may determine to retransmit a preamble and may ramp up the uplink transmit power. The UE may receive one or more RACH parameters (e.g., PREAMBLE_POWER_RAMPING_STEP) indicating a ramping step for the preamble retransmission. The ramping step may be an amount of incremental increase in uplink transmit power for a retransmission. The UE may ramp up the uplink transmit power if the UE determines a reference signal (e.g., SSB and / or CSI- RS) that is the same as a previous preamble transmission. The UE may count a number of preamble transmissions and / or retransmissions (e.g., PREAMBLE_TRANSMISSION_COUNTER). The UE may determine that a random access procedure completed unsuccessfully, for example, if the number of preamble transmissions exceeds a threshold configured by the one or more RACH parameters (e.g., preambleTransMax) .

[0185] The Msg 2 1312 received by the UE may include an RAR. In some scenarios, the Msg 2 1312 may include multiple RARs corresponding to multiple UEs The Msg 2 1312 may be received after or in response to the transmitting of the Msg 1 1311. The Msg 2 1312 may be scheduled on the DL-SCH and indicated on a PDCCH using a random access RNTI (RA-RNTI). The Msg 2 1312 may indicate that the Msg 1 1311 was received by the base station. The Msg 2 1312 may include a time-alignment command that may be used by the UE to adjust the UE’s transmission timing, a scheduling grant for transmission of the Msg 3 1313, and / or a Temporary Cell RNTI (TC-RNTI). After transmitting a preamble, the UE may start a time window (e.g., ra-ResponseWindow) to monitor a PDCCH for the Msg 2 1312. The UE 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 Typel-PDCCH common search space) configured by an RRC message. The UE may identify the RAR based on a Radio Network Temporary Identifier (RNTI). RNTIs may be used depending on one or more events initiating the random access procedure. The UE may use random access RNTI (RA-RNTI). The RA-RNTI may be associated with PRACH occasions in which the UE transmits a preamble. For example, the UE may determine the RA-RNTI based on: an OFDM symbol index; a slot index; a frequency domain index; and / or a UL carrier indicator of the PRACH occasions. An example of RA-RNTI may be as follows:

[0186] RA-RNTI= 1 + s_id + 14 x t_id + 14 x 80 x fjd + 14 x 80 x 8 x ul_carrier_id , where s_id may be an index of a first OFDM symbol of the PRACH occasion (e.g., 0 sjd < 14), t_id may be an index of aDocket No.: 24-1240PCT 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).

[0187] The UE may transmit the Msg 3 1313 in response to a successful reception of the Msg 2 1312 (e.g., using resources identified in the Msg 2 1312). The Msg 3 1313 may be used for contention resolution in, for example, the contention-based random access procedure illustrated in FIG. 13A. In some scenarios, a plurality of UEs may transmit a same preamble to a base station and the base station may provide an RAR that corresponds to a UE. Collisions may occur if the plurality of UEs interpret the RAR as corresponding to themselves. Contention resolution (e.g., using the Msg 3 1313 and the Msg 4 1314) may be used to increase the likelihood that the UE does not incorrectly use an identity of another the UE. To perform contention resolution, the UE may include a device identifier in the Msg 3 1313 (e.g., a C-RNTI if assigned, a TC-RNTI included in the Msg 2 1312, and / or any other suitable identifier).

[0188] The Msg 4 1314 may be received after or in response to the transmitting of the Msg 3 1313. If a C-RNTI was included in the Msg 3 1313, the base station will address the UE on the PDCCH using the C-RNTI. If the UE's unique C-RNTI is detected on the PDCCH, the random access procedure is determined to be successfully completed. If a TC-RNTI is included in the Msg 3 1313 (e.g., if the UE is in an RRCJDLE state or not otherwise connected to the base station), Msg 4 1314 will be received using a DL-SCH associated with the TC-RNTI. If a MAC PDU is successfully decoded and a MAC PDU comprises the UE contention resolution identity MAC CE that matches or otherwise corresponds with the CCCH SDU sent (e.g., transmitted) in Msg 3 1313, the UE may determine that the contention resolution is successful and / or the UE may determine that the random access procedure is successfully completed.

[0189] The UE may be configured with a supplementary uplink (SUL) carrier and a normal uplink (NUL) carrier. An initial access (e.g., random access procedure) may be supported in an uplink carrier. For example, a base station may configure the UE with two separate RACH configurations: one for an SUL carrier and the other for an NUL carrier. For random access in a cell configured with an SUL carrier, the network may indicate which carrier to use (NUL or SUL). The UE may determine the SUL carrier, for example, if a measured quality of one or more reference signals is lower than a broadcast threshold. Uplink transmissions of the random access procedure (e.g., the Msg 1 1311 and / or the Msg 3 1313) may remain on the selected carrier. The UE may switch an uplink carrier during the random access procedure (e.g., between the Msg 1 1311 and the Msg 3 1313) in one or more cases. For example, the UE may determine and / or switch an uplink carrier for the Msg 1 1311 and / or the Msg 3 1313 based on a channel clear assessment (e.g., a listen-before-talk).

[0190] 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 ofDocket No.: 24-1240PCT the procedure, transmit a configuration message 1320 to the UE. The configuration message 1320 may be analogous in some respects to the configuration message 1310. The procedure illustrated in FIG. 13B comprises transmission of two messages: a Msg 1 1321 and a Msg 2 1322. The Msg 1 1321 and the Msg 2 1322 may be analogous in some respects to the Msg 1 1311 and a Msg 2 1312 illustrated in FIG. 13A, respectively. As will be understood from FIGS. 13A and 13B, the contention-free random access procedure may not include messages analogous to the Msg 3 1313 and / or the Msg 4 1314.

[0191] The contention-free random access procedure illustrated in FIG. 13B may be initiated for a beam failure recovery, other SI request, SCell addition, and / or handover. For example, a base station may indicate or assign to the UE the preamble to be used for the Msg 1 1321 . The UE may receive, from the base station via PDCCH and / or RRC, an indication of a preamble (e g., ra-Preamblelndex).

[0192] After transmitting a preamble, the UE may start a time window (e.g., ra-ResponseWindow) to monitor a PDCCH for the RAR. In the event of a beam failure recovery request, the base station may configure the UE with a separate time window and / or a separate PDCCH in a search space indicated by an RRC message (e.g., recovery SearchSpaceld). The UE may monitor for a PDCCH transmission addressed to a Cell RNTI (C-RNTI) on the search space. In the con tent! on -free random access procedure illustrated in FIG. 13B, the UE may determine that a random access procedure successfully completes after or in response to transmission of Msg 1 1321 and reception of a corresponding Msg 2 1322. The UE may determine that a random access procedure successfully completes, for example, if a PDCCH transmission is addressed to a C-RNTI. The UE may determine that a random access procedure successfully completes, for example, if the UE receives an RAR comprising a preamble identifier corresponding to a 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.

[0193] 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.

[0194] Msg A 1331 may be transmitted in an uplink transmission by the UE. Msg A 1331 may comprise one or more transmissions of a preamble 1341 and / or one or more transmissions of a transport block 1342. The transport block 1342 may comprise contents that are similar and / or equivalent to the contents of the Msg 3 1313 illustrated in FIG. 13A. The transport block 1342 may comprise UCI (e.g., an SR, a HARQ ACK / NACK, and / or the like). The UE may receive the Msg B 1332 after or in response to transmitting the Msg A 1331. The Msg B 1332 may comprise contents that are similar and / or equivalent to the contents ofDocket No.: 24-1240PCT the Msg 2 1312 (e.g., an RAR) illustrated in FIGS. 13A and 13B and / or the Msg 4 1314 illustrated in FIG. 13A.

[0195] 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.

[0196] The UE may determine, based on two-step RACH parameters included in the configuration message 1330, a radio resource and / or an uplink transmit power for the preamble 1341 and / or the transport block 1342 included in the Msg A 1331. The RACH parameters may indicate a modulation and coding schemes (MCS), a time-frequency resource, and / or a power control for the preamble 1341 and / or the transport block 1342. A time-frequency resource for transmission of the preamble 1341 (e.g., a PRACH) and a time-frequency resource for transmission of the transport block 1342 (e.g., a PUSCH) may be multiplexed using 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.

[0197] 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).

[0198] 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.

[0199] 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 controlDocket No.: 24-1240PCT information (DCI). In some scenarios, the PDCCH may be a group common PDCCH (GC-PDCCH) that is common to a group of UEs.

[0200] 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).

[0201] DCIs may be used for different purposes. A purpose may be indicated by the type of RNTI used to scramble the CRC parity bits. For example, a DCI having CRC parity bits scrambled with a paging RNTI (P- RNTI) may indicate paging information and / or a system information change notification. The P-RNTI may be predefined as “FFFE” in hexadecimal. A DCI having CRC parity bits scrambled with a system information RNTI (SI-RNTI) may indicate a broadcast transmission of the system information. The SI-RNTI may be predefined as "FFFF” in hexadecimal. A DCI having CRC parity bits scrambled with a random access RNTI (RA-RNTI) may indicate a random access response (RAR) A DCI having CRC parity bits scrambled with a cell RNTI (C-RNTI) may indicate a dynamically scheduled unicast transmission and / or a triggering of PDCCH-ordered random access. A DCI having CRC parity bits scrambled with a temporary cell RNTI (TC-RNTI) may indicate a contention resolution (e.g. , a Msg 3 analogous to the Msg 3 1313 illustrated in FIG. 13A). Other RNTIs configured to the UE by a base station may comprise a Configured Scheduling RNTI (CS-RNTI), a Transmit Power Control-PUCCH RNTI (TPC-PUCCH-RNTI), a Transmit Power Control-PUSCH RNTI (TPC-PUSCH-RNTI), a Transmit Power Control-SRS RNTI (TPC-SRS-RNTI), an Interruption RNTI (INT-RNTI), a Slot Format Indication RNTI (SFI-RNTI), a Semi-Persistent CSI RNTI (SP-CSI-RNTI), a Modulation and Coding Scheme Cell RNTI (MCS-C-RNTI), and / or the like.

[0202] 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 SRSDocket No.: 24-1240PCT 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.

[0203] After scrambling a DCI with a RNTI, the base station may process the DCI with channel coding (e.g . , polar coding), rate matching, scrambling and / or QPSK modulation. A base station may map the coded and modulated DCI on resource elements used and / or configured for a PDCCH. Based on a payload size of the DCI and / or a coverage of the base station, the base station may transmit the DCI via a PDCCH occupying a number of contiguous control channel elements (CCEs). The number of the contiguous CCEs (referred to as aggregation level) may be 1 , 2, 4, 8, 16, and / or any other suitable number. A CCE may comprise a number (e.g., 6) of resource-element groups (REGs). A REG may comprise a resource block in an OFDM symbol. The mapping of the coded and modulated DCI on the resource elements may be based on mapping of CCEs and REGs (e.g., CCE-to-REG mapping).

[0204] 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.

[0205] 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.

[0206] 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 ofDocket No.: 24-1240PCTCCEs 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).

[0207] As shown in FIG. 14B, the UE may determine a time-frequency resource for a CORESET based on RRC messages. The UE may determine a CCE-to-REG mapping (e.g., interleaved or non-interleaved, and / or mapping parameters) for the CORESET based on configuration parameters of the CORESET. The UE may determine a number (e.g., at most 10) of search space sets configured on the CORESET based on the RRC messages. The UE may monitor a set of PDCCH candidates according to configuration parameters of a search space set. The UE may monitor a set of PDCCH candidates in one or more CORESETs for detecting one or more DCIs. Monitoring may comprise decoding one or more PDCCH candidates of the set of the PDCCH candidates according to the monitored DCI formats. Monitoring may comprise decoding a DCI content of one or more PDCCH candidates with possible (or configured) PDCCH locations, possible (or configured) PDCCH formats (e.g., number of CCEs, number of PDCCH candidates in common search spaces, and / or number of PDCCH candidates in the UE-specific search spaces) and possible (or configured) DCI formats. The decoding may be referred to as blind decoding. The UE may determine a DCI as valid for the UE, in response to CRC checking (e.g., scrambled bits for CRC parity bits of the DCI matching a RNTI value). The UE may process information contained in the DCI (e.g., a scheduling assignment, an uplink grant, power control, a slot format indication, a downlink preemption, and / or the like).

[0208] 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.

[0209] 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 theDocket No.: 24-1240PCT number of HARQ-ACK information bits with positive or negative SR (HARQ-ACK / SR bits) is one or two. PUCCH format 1 may occupy a number between four and fourteen OFDM symbols and may include two or fewer bits. The UE may use PUCCH format 1 if the transmission is four or more symbols and the number of HARQ-ACK / SR bits is one or two. PUCCH format 2 may occupy one or two OFDM symbols and may include more than two bits. The UE may use PUCCH format 2 if the transmission is over one or two symbols and the number of UCI bits is two or more. PUCCH format 3 may occupy a number between four and fourteen OFDM symbols and may include more than two bits. The UE may use PUCCH format 3 if the transmission is four or more symbols, the number of UCI bits is two or more and PUCCH resource does not include an orthogonal cover code. PUCCH format 4 may occupy a number between four and fourteen OFDM symbols and may include more than two bits. The UE may use PUCCH format 4 if the transmission is four or more symbols, the number of UCI bits is two or more and the PUCCH resource includes an orthogonal cover code.

[0210] 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”.

[0211] 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 PUCCHDocket No.: 24-1240PCT 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.

[0212] FIG. 15 illustrates an example of a wireless device 1502 in communication with a base station 1504 in accordance with embodiments of the present disclosure. The wireless device 1502 and base station 1504 may be part of a mobile communication network, such as the mobile communication network 100 illustrated in FIG. 1A, the mobile communication network 150 illustrated in FIG. 1 B, or any other communication network. Only one wireless device 1502 and one base station 1504 are illustrated in FIG. 15, but it will be understood that a mobile communication network may include more than one UE and / or more than one base station, with the same or similar configuration as those shown in FIG. 15.

[0213] 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.

[0214] 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.

[0215] 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.

[0216] 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 mayDocket No.: 24-1240PCT 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.

[0217] As shown in FIG. 15, a wireless device 1502 and the base station 1504 may include multiple antennas. The multiple antennas may be used to perform one or more MIMO or multi-antenna techniques, such as spatial multiplexing (e.g., single-user MIMO or multi-user MIMO), transmit / receive diversity, and / or beamforming. In other examples, the wireless device 1502 and / or the base station 1504 may have a single antenna.

[0218] 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.

[0219] The processing system 1508 and / or the processing system 1518 may comprise one or more controllers and / or one or more processors. The one or more controllers and / or one or more processors may comprise, for example, a general-purpose processor, a digital signal processor (DSP), a microcontroller, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) and / or other programmable logic device, discrete gate and / or transistor logic, discrete hardware components, an onboard unit, or any combination thereof. The processing system 1508 and / or the processing system 1518 may perform at least one of signal coding / processing, data processing, power control, input / output processing, and / or any other functionality that may enable the wireless device 1502 and the base station 1504 to operate in a wireless environment.

[0220] 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)Docket No.: 24-1240PCT radio unit, a media player, an Internet browser, an electronic control unit (e.g., for a motor vehicle), and / or one or more sensors (e.g., an accelerometer, a gyroscope, a temperature sensor, a radar sensor, a lidar sensor, an ultrasonic sensor, a light sensor, a camera, and / or the like). The processing system 1508 and / or the processing system 1518 may receive user input data from and / or provide user output data to the one or more peripherals 1516 and / or the one or more peripherals 1526. The processing system 1518 in the wireless device 1502 may receive power from a power source and / or may be configured to distribute the power to the other components in the wireless device 1502. The power source may comprise one or more sources of power, for example, a battery, a solar cell, a fuel cell, or any combination thereof. The processing system 1508 and / or the processing system 1518 may be connected to a GPS chipset 1517 and a GPS chipset 1527, respectively. The GPS chipset 1517 and the GPS chipset 1527 may be configured to provide geographic location information of the wireless device 1502 and the base station 1504, respectively.

[0221] 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.

[0222] 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.

[0223] 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 anDocket No.: 24-1240PCT 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.

[0224] 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.

[0225] A wireless device may receive from a base station one or more messages (e.g., RRC messages) comprising configuration parameters of a plurality of cells (e.g., primary cell, secondary cell). The wireless device may communicate with at least one base station (e.g., two or more base stations in dual connectivity) via the plurality of cells. The one or more messages (e.g., as a part of the configuration parameters) may comprise parameters of physical, MAC, RLC, PCDP, SDAP, RRC layers for configuring the wireless device. For example, the configuration parameters may comprise parameters for configuring physical and MAC layer channels, bearers, etc. For example, the configuration parameters may comprise parameters indicating values of timers for physical, MAC, RLC, PCDP, SDAP, RRC layers, and / or communication channels.

[0226] 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.

[0227] FIG. 17 illustrate examples as per aspects of embodiments of the present disclosure. In an example, a base station (BS(s)) may communicate with a wireless device (UE). For example, the base station configures a cell (CC#1) to the wireless device.

[0228] The base station may configure a TAG for the cell.

[0229] In an example, downlink, uplink and sidelink transmissions may be organized into frames. A duration of a frame may be 10 msec. The duration of the frame may be a number of a sample duration (Tc). The frame may comprise M subframes (e.g., M = 10). Each subframe may comprise N number of symbolsDocket No.: 24-1240PCT based on a subcarrier spacing of a carrier. For example, N may be a function of a number of slots, based on the subcarrier spacing, and a number of symbols in a slot. For example, with 15 kHz subcarrier spacing, a subframe may comprise N = 14 symbols with normal CP, and N = 12 with extended CP.

[0230] In an example, the carrier may comprise a first set of frames in the uplink and a second set of frames in the downlink on the carrier.

[0231] An uplink frame number #i for transmission from a wireless device may start a timing advance (T_TA), as illustrated in FIG. 17, before a start of a corresponding downlink frame (e.g., Downlink frame #i) at the wireless device (e.g., a time T3). In the example, a time corresponding to the start of a downlink frame #i at the wireless device is at T3. In the example, the start time of the downlink frame #i (T3) at the wireless device may be determined based on a propagation delay (e.g., N_TA / 2) between the base station and the wireless device and a timing of a downlink frame #i at the base station (e.g., T2). For example, a gap between a start time of a downlink frame #i at the base station (T2) and the start time of the downlink frame #i at the wireless device is a propagation delay or a timing advance value (e.g., N_TA * Tc) divided by 2 (to compensate one way propagation delay).

[0232] The wireless device may determine / compute / update / maintain the timing advance (T_TA) based on a timing advance value (N_TA) and a timing advance (TA) offset (N_TA_offset). For example, T_TA = (N_TA + N_TA_offset) *Tc. For example, T_TA = (N_TA + N_TA_offset + N_TA_adj_common + N_TA_adj_UE) *Tc. The base station may determine the timing advance value (N_TA*Tc) based on estimation / measurement of a round-trip-time (e.g., based on a propagation delay) between the base station and the wireless device.

[0233] For example, the wireless device may receive one or more RRC messages indicating / comprising a ta-Common, a ta-CommonDrift and a ta-Common DriftVariant. The wireless device may determine N_TA_adj_common as zero in response to not being provided with the ta-Common, the ta-CommonDrift and the ta-CommonDriftVariant via the one or more RRC messages The one or more RRC messages may indicate one or more serving-satellite-ephemeris-related parameters. The wireless device may determine N_TA_adj_UE in response to receiving the one or more RRC messages indicating / comprising the one or more serving-satellite-ephemeris-related parameters. In other cases, the wireless device may determine N_TA_adj_UE as zero.

[0234] A start time of an uplink frame #i at the wireless device (e.g., TO) may be determined based on the timing advance (T_TA) and the start time of the downlink frame #i at the wireless device (e.g., T3). The gap between T1 and T3 may be the timing advance.

[0235] A start time of the uplink frame #i at the base station (e.g., T1) may be TO + a propagation delay from the wireless device to the base station (or TO + N_TA*Tc / 2).Docket No.: 24-1240PCT

[0236] The wireless device may apply the timing advance (T_TA) for an uplink transmission in the uplink frame #i for a PUCCH, a PUSCH (not comprising a msgA) or an SRS. The wireless device may apply only a TA offset value (e.g., N_TA_offset*Tc) for an uplink transmission in the uplink frame #i for a PRACH or a PUSCH comprising a msgA. In an example, a msgA may comprise a PRACH preamble and a PUSCH comprising a contention resolution payload. In an example, the wireless device may apply the TA offset value (N_TA_offset *Tc) for both the PRACH preamble of the msg A and the PUSCH comprising the contention resolution payload.

[0237] In an example, the one or more RRC messages may comprise / indicate the TA offset (N_TA_offset, TA_offset, TA offset). In some cases, the one or more RRC messages may not comprise one or more parameters of the timing advance (TA) offset. In such a case, the wireless device may determine the TA offset (e.g., N_TA_offset *Tc) for the cell based on one or more predefined or pre-configured values. In an example, at least a TAG is associated with the

[0238] For example, the base station may transmit one or more RRC messages comprising / indicating a N_TA_offset value for a cell. The wireless device may determine a TA offset value based on the N_TA_offset. In response to not receiving the N_TA_offset from the base station, the wireless device may determine N_TA_offset based on one or more (pre-)configured / determined values. For example, the wireless device may determine N_TA_offset as 25600, where N_TA_offset * Tc may correspond to 13 us for a serving cell operating in a TDD duplex mode and N_TA_offset as 0 for a serving cell operating in a FDD duplex mode in a frequency range 1 (e.g., below 7 GHz). In an example, the wireless device may determine N_TA_offset as 39936 that corresponding to 20 us for a serving cell if the serving cell may operate in a frequency band where LTE base station may operate.

[0239] In an example, the cell may be associated with a plurality of TAGs. The TA offset may be associated with a TAG of the plurality of TAGs that has a lowest index among those of the plurality of TAGs. The TA offset may be associated with a TAG, of the plurality of TAGs, that is associated with a coreset pool with a coreset pool index = 0. The TA offset may be associated with a TAG, of the plurality of TAGs, that is associated with a primary cell identifier (PCI) of the cell. The TA offset may be associated with a TAG, of the plurality of TAGs, that is associated with a TCI state of a CORESET #0 of the cell.

[0240] In the specification, a TA offset (or a TA offset, N_TA_offset, TA_offset) may be associated with a TAG of a cell, where the TAG is associated with a coreset pool with a coreset pool index = 0, a PCI of the cell, a TCI state of a CORESET#0 of the cell, and / or the like. A second TA offset (or a second TA offset, N_TA_offset2, TA_offset2) may not be associated with the TAG of the cell or may be associated with the TAG of the cell.

[0241] In an example, a wireless device may be configured with a first UL carrier and a second UL carrier for a serving cell. In an example, the first UL carrier is an UL carrier. The second UL carrier is aDocket No.: 24-1240PCT supplemental UL (SUL) carrier. The wireless device may determine a single TA offset value applicable to both the first UL carrier and the second UL carrier in such a case. The wireless device may consider it as an error case, if the base station configures the second TA offset for the serving cell that is configured with the first UL carrier and the second UL carrier. In the example, the second UL carrier may be a supplemental uplink (SUL) carrier.

[0242] In an example, a wireless device may determine a single timing advance (TA) value (e.g., T_TA) for one or more serving cells that are associated / configured with or belong to a same TA group (TAG).

[0243] In an example, the base station may transmit one or more downlink control messages (e.g., MAC CE, RRC, DCI) comprising a timing advance command for a TAG. The one or more downlink control messages may comprise one or more MAC CEs that comprise the timing advance command for the TAG. The timing advance command may comprise one or more timing advance values. The one or more downlink control messages and / or the timing advance command (TAG) may comprise or indicate a TAG ID of the TAG.

[0244] In response to receiving the one or more downlink control messages for the TAG, the wireless device may update / adjust / determine an uplink timing for one or more PUSCH / SRS / PUCCH transmissions on one or more serving cells, that share the TAG, based on the one or more timing advance values and a value of a TA offset of the TAG. When a serving cell of the one or more serving cells is configured with a first TAG and a second TAG, the wireless device may be configured / indicated with a first TA offset and a second TA offset. The first TA offset is associated with the first TAG and the second TA offset is associated with the second TAG. The wireless device may apply the first TA offset or the second TA offset based on the TAG ID on the TAG and / or the one or more downlink control messages.

[0245] In response to receiving the one or more downlink signal, the wireless device may determine / update a timing advance (T_TA) based on the TA offset (N_TA_offset) and the one or more timing advance values.

[0246] The TA offset for a serving cell of the one or more serving cells may be configured via one or more RRC messages or may be determined based on one or more pre-defined values. In an example, the serving cell may be a primary cell of a cell group. In an example, the serving cell may be a secondary cell.

[0247] In an example, the wireless device may determine a TA offset based on a duplexing mode of a serving cell and / or a frequency band that the serving cell operates. For example, the wireless device may determine the TA offset as zero / 0 in response to the serving cell operating in the frequency band lower than 7GHz based on FDD duplexing mode. The wireless device may determine a non-zero value for the TA offset in response to the serving cell operating based on TDD duplexing mode.

[0248] In an example, a wireless device may receive a downlink data (e.g., via PDSCH) comprising a MAC CE (e.g., comprising a TAG ID and a timing advance value) to update a timing advance, of a TAGDocket No.: 24-1240PCT associated with the TAG ID, based on a current uplink timing for the TAG. The wireless device may update a timing advance (T_TA) of the TAG based on the timing advance value. For example, the wireless device may determine a new value N_TA_new as N_TA_old (N_TA value at current) + (the timing advance value- 31) * 16 * 64 / M, where M is power (2, u) and u is determined based on a subcarrier spacing of the serving cell compared to 15 kHz (e.g., u = 2 in case of 60 kHz).

[0249] For example, an updated timing advance may be computed / determined based on a current timing advance and a received timing advance command / timing advance value. The received timing advance command and / or timing advance value may be conveyed / transmitted / delivered via one or more MAC CEs and / or RARs.

[0250] The wireless device may update a timing advance that is addition to a current timing advance and (a timing advance value - 31) * 16*64 / power (2, u). In the example, u may be determined based on a subcarrier spacing of an active BWP of a serving cell. For example, the subcarrier spacing of the active BWP = power (2, u) * 15 kHz.

[0251] The timing advance value via the MAC CE may comprise a value from {0, 1 , 2, .... 63}. A subcarrier spacing of an active BWP of the serving cell may be power (2, u) * 15 kHz.

[0252] For example, a wireless device may switch from a first BWP to a second BWP as an active BWP of a serving cell, the wireless device may use a subcarrier spacing of the second BWP to determine a timing advance or to apply a timing advance command / timing advance value for a TAG for the serving cell.

[0253] In an example, the wireless device may receive a second TAC (e.g., comprising an absolute timing advance value), comprising a second timing advance value, that indicates adjustments of a current N_TA (N_TA_old) to a new N_TA (N_TA_new). The wireless device may update the new timing advance (N_TA_new) as the second timing advance value * 16 / 64 / power(2,u) *Tc.

[0254] In an example, a wireless device may receive a RAR comprising a TAC. The RAR may indicate a TAG ID of a TAG to apply the TAC. The TAC may comprise a timing advance value. In response to receiving the RAR, the wireless device may replace a current timing advance of the TAG with a new timing advance determined / computed based on the timing advance value.

[0255] In response to the receiving the RAR, the wireless device may apply a timing advance (T_TA) for a transmission other than a PUSCH scheduled by a RAR UL grant or a fallbackRAR UL grant or a PUCCH with HARQ-ACK information in response to a successRAR. The wireless device may transmit the transmission via a cell associated with the TAG.

[0256] In an example, for operation with a single TAG for a serving cell, if two adjacent slot overlap based on a timing advance adjustment / command or based on updating a current N_TA value, the wireless device may reduce a latter slot duration. The wireless device may not change a N_TA during a transmission.Docket No.: 24-1240PCT

[0257] A wireless device may support a plurality of TAGs for a serving cell. For example, the wireless device supports two TAGs for a serving cell. The serving cell may operate a multi-TRP scenario. A base station of the serving cell comprises a first TRP (TRP#1) and a second TRP (TRP#2). The wireless device may indicate to support the plurality of TAGs for the serving cell (e.g., via multiDCI-lnterCellMultiTRP- TwoTA).

[0258] The base station may transmit one or more RRC messages indicating / comprising parameters indicating a plurality of coreset pools. For example, the plurality of coreset pools comprise a first coreset pool and a second coreset pool. In an example, a first coreset pool (Coreset Pool#1 ) may correspond to the first TRP. In an example, a coreset pool index of the first coreset pool may be indicated via the one or more RRC messages. In an example, the wireless device may determine a coreset pool index of the first coreset pool as a predefined value (e.g., zero / 0) in response to not being indicated / configured with the coreset pool index via the one or more RRC messages. In an example, the one or more RRC messages may not indicate the first coreset pool. The wireless device may determine a coreset pool index of one or more coresets as a predetermined value, where the first coreset pool comprises the one or more coresets.

[0259] A second coreset pool (Coreset Pool#2) , of the plurality of coreset pools, may correspond to the second TRP. In an example, a second coreset pool index of the second coreset pool may be indicated via the one or more RRC messages.

[0260] In an example, the first coreset pool may be associated with or be configured with or be tied with a first TCI state.

[0261] In an example, the second coreset pool may be associated with or be configured with or be tied with a second TCI state.

[0262] The wireless device may be equipped with a plurality of panels. In the example, the wireless device is equipped with a first panel (Panel#1 ) and a second panel (Panel#2). The first panel and the second panel may be a same or different.

[0263] In the specifications, a spatial domain filter parameter may be referred as a spatial domain filter, a spatial RX parameter, a spatial RX filter, a spatial parameter, and / or the like.

[0264] In an example, the first panel may be associated with or be configured with or be tied with a first spatial domain filter (Spatial Domain Filter #1).

[0265] In an example, the second panel may be associated with or be configured with or be tied with a second spatial domain filter (Spatial Domain Filter #2).

[0266] The one or more RRC messages may configure / indicate / comprise parameters of a first TAG and a second TAG for the serving cell. In an example, the first TAG of the plurality of TAGs may be associated with or be configured with or be tied with the first spatial domain filter (Spatial Domain Filter #1).Docket No.: 24-1240PCT

[0267] In an example, the second TAG of the plurality of TAGs may be associated with or be configured with or be tied with the second spatial domain filter (Spatial Domain Filter #2).

[0268] In an example, the wireless device may receive one or more second RRC messages indicating / comprising a TA offset (N_TA_offset) for a serving cell (e.g., a parameter of n- TimingAdvanceOffset for the serving cell). When the wireless device is provided / configured with a plurality of coreset pools for the serving cell, the one or more second RRC messages may indicate a second TA offset (e.g., a second N_TA_offset) for the serving cell (e.g., a second parameter of n- TimingAdvanceOffset2).

[0269] The wireless device may be provided / configured with the plurality of coreset pools. The plurality of coreset pools may comprise a first coreset pool with a first corset pool index being 0 (zero) and a second coreset pool with a second coreset pool index being 1 (one). The wireless device may be provided / configured with the plurality of coreset pools that comprise a first coreset without a first coreset pool index being configured via RRC signaling and a second coreset with a second coreset pool index being configured via RRC signaling as one / 1 .

[0270] The wireless device may apply / use the TA offset for one or more transmissions associated with or based on or with one or more first spatial domain filters. In an example, the wireless device may determine one or more transmission configuration / parameters based on the one or more first spatial domain filters. The one or more first spatial domain filters may be associated with or corresponding to one or more first TCI states For example, the one or more first spatial domain filters comprise the first spatial domain filter (Spatial Domain Filter #1). The one or more first TCI states comprise the first TCI state. The first TCI state is associated with the first coreset pool (Coreset Pool #1).

[0271] In an example, the wireless device may apply / use the second TA offset for one or more second transmissions associated with or based on or with one or more second spatial domain filters. The one or more second spatial domain filters may be associated with or corresponding to one or more second TCI states. For example, the one or more second spatial domain filters comprise the second spatial domain filter (Spatial Domain Filter #2). The one or more second TCI states comprise the second TCI state. The second TCI state is associated with the second coreset pool (Coreset Pool #2).

[0272] In another example, the wireless device may receive the one or more RRC messages indicating / comprising the second TA offset for one or more second transmissions associated with or based on or with one or more second spatial domain filters. The one or more second spatial domain filters may be associated with or corresponding to one or more second TCI states or one or more SSB receptions associated with / tied with / corresponding to a second physical cell index (e.g., physCell Id) that is different from a first physical cell index of the serving cell. The wireless device may apply / use the TA offset for the one or more first uplink transmissions associated with or based on or with one or more first spatial domainDocket No.: 24-1240PCT filters. The one or more first spatial domain filters may be associated with or corresponding to one or more first TCI states or one or more SSB receptions associated with / tied with / corresponding to a first physical cell index (e.g., physCellld) of the serving cell.

[0273] In an example, the TA offset may be used for the first timing advance group (TAG) for the serving cell. The second TA offset may be used for / associated with the second TAG for the serving cell. The wireless device may be configured / indicated with the first TAG and the second TAG for the serving cell. For example, a first ID of the first TAG is a first TAG-ID. A second ID of the second TAG is a second TAG-ID.

[0274] A MAC CE indicating one or more timing advance values (e.g., a MAC CE to update a timing advance value or a MAC to indicate an absolute timing advance value conveyed via a random access response) for one of the first TAG and the second TAG.

[0275] In an example, a RAR comprise a bit field that indicate / comprise a TAG identifier pointer (e.g., tag- Id-ptr) between a first value (e.g., 0) and a second value (e.g., 1). The first value may indicate / be associated with the one or more first TCI states and the second value may indicate / be associated with the one or more second T Cl states, in response to a joint T Cl state between downlink and uplink being enabled / configured / indicated (e.g., being configured with dl-OrJointTCI-StateList comprising the one or more first TCI states and the one or more second TCI states). The first value may indicate / be associated with the first TAG. The second value may indicate / be associated with the second TAG.

[0276] In another example, the first value may indicate / be associated with one or more first UL TCI states and the second value may indicate / be associated with one or more second UL TCI states, in response to a joint TCI state between downlink and uplink not being enabled / configured / indicated (or in response to being configured with a ul-TCI-State-List comprising the one or more first UL TCI states and the one or more second UL TCI states). In the example, the one or more first UL TCI states may be associated with or corresponding to the one or more first spatial domain filter parameters. The one or more second UL TCI states may be associated with or corresponding to the one or more second spatial domain filter parameters.

[0277] In another example, the first value may indicate / be associated with the one or more first spatial domain filters and the second value may indicate / be associated with the one or more second spatial domain filters, in response to.

[0278] In the examples, the first value may indicate / be associated with the first TAG. The second value may indicate / be associated with the second TAG. The first TAG may be associated with the one or more first TCI states (if dl-OrJointTCI-StateList is provided), the one or more first UL TCI states (if ul-TCI-State- List is provided). The second TAG may be associated with the one or more second TCI states (if dl- OrJointTCI-StateList is provided), the one or more second UL TCI states (if ul-TCI-State-List is provided)Docket No.: 24-1240PCT

[0279] In an example, a wireless device may receive one or more timing advance commands (TACs) for a TAG. The one or more timing advance command may be conveyed via one or more MAC CEs / PDSCHs. In an example, a first a MAC CE may indicate an identifier of a TAG (TAG ID) and a TAG. The TAC may comprise a timing advance value to adjust / update / apply a TA of the TAG with the TAG ID compared to a current TA for a serving cell. The wireless device may apply / update / adjust the TA of the TAG based on the timing advance value of the TAC and the TAG ID based on the first MAC CE. In an example, the wireless device may add the timing advance value to the current TA of the TAG.

[0280] In an example, a second MAC CE may indicate a first TAG identifier point (e.g., tag-ld-ptr = 0) or a second TAG identifier pointer (e.g., tag-ld-ptr = 1) for a serving cell and an absolute timing advance value for the serving cell. For example, based on a tag2 flag (e.g., tag2-flag) being set to FALSE (0), the first TAG identifier point with value 0 may correspond to the first TAG and the second TAG identifier point with value 1 may correspond to the second TAG. For example, based on the tag2 flag (e.g., tag2-flag) being set to TRUE (1), the first TAG identifier point with value 0 may correspond to the second TAG and the second TAG identifier point with value 1 may correspond to the first TAG.

[0281] In an example, when a wireless device is configured / indicated with a plurality of TAGs for a serving cell, based on a capability, the wireless device may reduce in duration a latter transmission using a first TAG (e.g., tag-ld-ptr = 0) of the plurality of TAGs to avoid overlapping with a former transmission using a second TAG (e.g., tag-ld-ptr = 1) of the plurality of TAGs.

[0282] In an example, a MAC CE of a timing advance update / command may comprise a TAG ID and a timing advance value. The wireless device may apply the timing advance value to a TAG with the TAG ID.

[0283] In RRC_CONNECTED, a base station may maintain the timing advance to keep a layer 1 (L1) of a wireless device synchronized. Serving cells having / with uplink to which the same timing advance applies and using the same timing reference cell may be grouped, by the bases station, in a TAG of one or more TAGs. Each TAG of the one or more TAGs may contain / comprise at least one serving cell configured with uplink. The mapping of each serving cell to a (respective) TAG may be configured / indicated by RRC configuration parameters (e.g., tag-id).

[0284] For a primary TAG (pTAG), the wireless device may use the PCell as timing reference, except with shared spectrum channel access where an SCell can also be used in certain cases. In a secondary TAG (sTAG), the wireless device may use any of the activated SCells of this TAG (or the sTAG) as a timing reference cell.

[0285] Timing advance updates may be signaled / indicated by the base station to the wireless device via MAC CE commands. Based on receiving the MAC CE commands, the wireless device may start or restart a TAG-specific timer (e g., time alignment timer). The TAG-specific timer may indicate whether the L1 of the wireless device is synchronised or not. For example, when the TAG-specific timer is running, the L1Docket No.: 24-1240PCT may be (considered) synchronised. When the TAG-specific timer is not running, the L1 may be (considered) non-synchronised. When the L1 is non-synchronised, the wireless device may transmit / perform an uplink transmission through / via MSG1 / MSGA. When the L1 is non-synchronised, the wireless device may not transmit / perform an uplink transmission through / via PUSCH / PUCCH / SRS.

[0286] For an inter-cell multi-DCI multi-TRP operation and an intra-cell multi-DCI multi-TRP operation, two TAGs with associated two TAG IDs may be configured per a serving cell. Each TAG of the two TAGs may be associated with a respective TAG ID of the two TAG IDs. Each uplink / joint TCI state may be associated with a respective TAG ID of the two TAG IDs. The wireless device may apply a timing advance of a TAG ID associated with an uplink / joint TCI state utilized for uplink transmission(s).

[0287] When two TAG IDs are configured for a serving cell, a TAG for which the timing advance command is applied, by the wireless device, may be indicated in a random access response message or in a MSGB.

[0288] When two TAG IDs are configured for a PCell, both TAGs may be regarded as primary TAG.

[0289] 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. In the specification, a SSB may represent a SS / PBCH block.

[0290] The SSB burst is transmitted in the first half of a radio frame of 10 ms. 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 one example, the SSB burst may be indicated / configured by ssb- periodicityServingCell or set to 5ms as a default.

[0291] In an example, the SSB / SSB burst (i.e. , each SSB of the SSB burst) may be transmitted in a periodicity.

[0292] 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.

[0293] 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.

[0294] The base station does not transmit the SSB burst in the remaining 15 ms of the each 20 ms.

[0295] 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).

[0296] 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.Docket No.: 24-1240PCT

[0297] 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.

[0298] 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.

[0299] 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 CORESETO 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.

[0300] 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.

[0301] 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.

[0302] 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) .

[0303] In an example, a wireless device may receive one or more configuration parameters for non-cell defining SSBs via one or more configuration parameters for a downlink bandwidth part for a cell (e.g., BWP-DownlinkDedicated) or via a RRC release for a small data transmission (e.g., SuspendConfig).

[0304] 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 the 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.

[0305] 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.

[0306] The default transmission repetition periodicity of SIB1 is 20 ms.

[0307] The base station may determine an actual transmission repetition periodicity based on network implementation.Docket No.: 24-1240PCT

[0308] 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.

[0309] 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 noninitial BWP of the cell.

[0310] 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}.

[0311] 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) cell 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.

[0312] 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.Docket No.: 24-1240PCTThe 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).

[0313] 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}.

[0314] FIG. 18 shows examples of a variety of SSB transmissions.

[0315] In an example, a base station may configure a serving cell (e.g., a PCell or a SCell, Cell 1 in FIG. 18) with (always-on / periodic) SSBs, in which case, the base station keeps transmitting the SSBs with periodicity (e.g., ssb-PeriodicityServingCelf} based on configuration parameters of the SSBs.

[0316] The SSBs may be transmitted in a way that a number (e.g., indicated by ssb-PositionslnBursf) 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.

[0317] 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 during RRCJdle / 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.Docket No.: 24-1240PCT

[0318] 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).

[0319] As shown in FIG. 18, a base station may configure a serving cell (e.g., a SCell, Cell 2 in FIG. 18) 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. 18) 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. 18) based on one or more configuration parameters. For example, the one or more configuration parameters for a frequency information of downlink (e.g., FrequencylnfoDL) 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 FrequencylnfoDL). The one or more configuration parameters may comprise a cell index of the reference cell (e.g., referenceCell in frequencylnfoDL) 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.

[0320] 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 FrequencylnfoDL) of the serving cell.

[0321] 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.

[0322] 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).

[0323] As shown in FIG. 18, a base station may configure a serving cell (e.g., a SCell, e.g., Cell 3) with on-demand SSB transmissions, e.g., in order to provide SSBs for time / frequency synchronization and / or parallel ly reduce power consumption of the serving cell especially when there is no SSB reference cell for this serving cell (e.g., due to a single cell deployment, or time / frequency synchronization error between the SSB reference cell and this serving cell being greater than the threshold).

[0324] There are multiple ways of providing the on-demand SSBs for this serving cell.

[0325] As a first way (as shown in FIG. 18) 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.Docket No.: 24-1240PCT

[0326] 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.

[0327] 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.

[0328] 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).

[0329] 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.

[0330] 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.

[0331] As a second way (as shown in FIG. 18) 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.

[0332] Before the SCell is activated, the base station may skip (or may stop / refrain from) transmitting the on-demand SSBs.

[0333] 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 SSB transmissions) based on traffic load / request of wireless device(s) and / or requests from another base station via backhaul link.

[0334] 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.

[0335] 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 MACDocket No.: 24-1240PCTCEs (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.

[0336] 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.

[0337] 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.

[0338] In an example, a SSB configurations for a SCell may be configured to a wireless device.

[0339] In an example, a wireless device may receive from a base station one or more RRC messages (e.g , RRCReconfiguration IE). The one or more RRC messages may comprise configuration parameters (e.g., comprised in CellG roupConfig IE) of cell group. The configuration parameters of a cell group may comprise SCell configuration parameters of a plurality of SCells (e.g., sCeliToAdd Mod List IE).

[0340] The SCell configuration parameters of each SCell may comprise a SCell index (sCelllndex), cell common parameters (comprised in ServingCellConfigComm IE) of the SCell, cell parameters (comprised in ServingCellConfig IE) dedicated for the UE of the SCell, and / or a SSB measurement timing configuration (SMTC) (e.g., smtc).

[0341] In an example, a smtc is associated with a periodicityAndOffset and a duration.

[0342] 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.

[0343] 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 .

[0344] 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.

[0345] If the SCell is an SSB-less SCell (i.e. , the IE absoluteFrequencySSB in ServingCellConfigCommon is absent), the smtc field is absent.Docket No.: 24-1240PCT

[0346] 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.

[0347] 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(Per / od / c / fy / 10).

[0348] In an example, the base station (or the network) may configure the wireless device in RRCJSONNECTED 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.

[0349] The cell common parameters of the SCell may comprise downlink common configuration parameters (e.g., comprised in DownlinkConfigCommon IE), SSB burst configuration (ssb- PositionsinBursf), SSB periodicity (ssb-periodicityServingCelf), SSB subcarrier spacing (ssbSubcarrrierSpacing) and SSB transmission power (ss-PBCH-BlockPower).

[0350] The downlink common configuration parameters of the SCell may comprise downlink frequency information (e.g., comprised in FrequencylnfoDL), configuration parameters of initial downlink BWP etc. The downlink frequency information of the SCell may comprise a parameter (absoluteFrequencySSB) indicating the frequency of the SSB to be used for this SCell.

[0351] 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 referenceCeil, or from the "default cell" if the referenceCell is absent.

[0352] 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.Docket No.: 24-1240PCT

[0353] 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 (referenceCel!) is absent, a "default cell" is the reference cell.

[0354] FIG. 19 shows an example of on-demand SSB transmissions for a SCell.

[0355] 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.

[0356] 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.

[0357] 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.

[0358] In the example of FIG. 19, 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.

[0359] 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. 20 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. 20 during which the UE has received the SCell activation command); or the first transmission occasion of on-demand SSB burst T slots after the slot where the wireless device receives the signaling / command from the base station to trigger the on-demand SSB transmissions or transmits HARQ- ACK corresponding to the signaling / command.

[0360] In an example, the time instance B may be determined based on examples of FIG. 21 which will be described later in this specification.

[0361] In the example of FIG. 19, 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.

[0362] In the example of FIG. 19, 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 ofDocket No.: 24-1240PCT whether the SCell is in an activated state or in a deactivated state if the always-on SSBs are configured on the SCell.

[0363] In the example of FIG. 19, 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.

[0364] In the example of FIG. 19, 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.

[0365] In the example of FIG. 19, 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.

[0366] In an example, the on-demand SSB triggering / command / signaling may be a RRC message, a MAC CE and / or a DCI.

[0367] 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.

[0368] FIG. 20 shows an example of on-demand SSB transmission scenarios for a SCell, e.g., based on examples of FIG. 19. In the example of FIG. 20, the legacy SSBs (e.g., always-on SSBs) are illustrated as a purpose of comparison with the on-demand SSBs.

[0369] In the example of FIG. 20, in a first scenario (Scenario 1) of on-demand SSB triggering, after a SCell is configured (e.g., by RRC messages) and before the SCell is activated, the base station transmits the on-demand SSB triggering / command / signaling indicating transmission of the on-demand SSBs via the SCell before the wireless device receives, and / or the base station transmits, a SCell Activation / deactivation MAC CE (or a SCell activation command) indicating an activation of the SCell. The wireless device, based on the on-demand SSBs (with a transmission periodicity P1), may perform downlink synchronization, AGC tuning and / or L3 measurement / report for the SCell.

[0370] 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 SCellDocket No.: 24-1240PCT

[0371] 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.

[0372] In an example, the wireless device may determine whether a SCell is a known cell or a unknow cell.

[0373] 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.

[0374] 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.

[0375] 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.

[0376] In the example of FIG. 20, 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.

[0377] 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.

[0378] 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.

[0379] 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.Docket No.: 24-1240PCT

[0380] In an example, different scenarios (e.g., Scenario 1 and Scenario 2 as shown in FIG. 20) may be applied by the base station for different purposes.

[0381] 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.

[0382] 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.

[0383] Scenario 1 in FIG. 20 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.

[0384] Scenario 2 in FIG. 20 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.

[0385] FIG. 21 shows an example of on-demand SSB transmissions for a SCell, e.g., based on examples of FIG. 19 and / or FIG. 20. 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.

[0386] In the example of FIG. 21 , 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. 19), 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 more 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.

[0387] In the example of FIG. 21 , 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 timeDocket No.: 24-1240PCT 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).

[0388] In the example of FIG. 21 , 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.

[0389] In the example of FIG. 21 , 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).

[0390] In the example of FIG. 21 , 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. 21) 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. 21). 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.

[0391] Examples of FIG 19, FIG. 20 and / or FIG. 21 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. 19 may be combined with Scenario 1 of FIG. 20 (and / or with option 1A / 2 / 3 of FIG. 21) to reduce both power consumption of the base station and / or the wireless device and / or SCell activation delay. Case 2 of FIG. 19 may be combined with Scenario 2 of FIG. 20 (and / or with option 1A / 2 / 3 of FIG. 21) to improve L3Docket No.: 24-1240PCT measurement accuracy of the wireless device and / or reduce power consumption of the wireless device, etc.

[0392] 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-ToAddLisf) 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.

[0393] 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.

[0394] 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 colocation 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 one 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).

[0395] A TCI state may be configured via information element of TCI-State. One or more configuration parameters of a TCI state may be referred as a TCI state configuration, a TCI state or a TCI in the specification.

[0396] A wireless device may be configured with a list of TCI states (e.g., up to 128 TCI-State configurations) within / by a higher layer parameter dl-OrJointTCI-StateList in PDSCH-Config. A PDSCH- Config may be configured for each / a bandwidth part of a cell. A TCI state in the list of TCI states may provide / indicate a reference signal for a quasi co-location for i) DM-RS of a PDSCH, ii) DM-RS of a PDCCH in a BWP / cell, and / or ill) a CSI-RS. A TCI state in the list of TCI states may provide / indicate one or moreDocket No.: 24-1240PCT reference signals for determining uplink transmission spatial filter for I) a dynamic-grant PUSCH, ii) a configured-grant based PUSCH, iii) a PUCCH resource in a BWP / cell, and / or, iv) an SRS.

[0397] The TCI state may comprise an index of the TCI state (e.g., tci-Stateld) and parameter(s) to indicate a first reference signal for determining QCL with a first QCL type (e.g., qcl-Type1). Additionally, the TCI state may comprise parameter(s) to indicate a second reference signal for determining QCL with a second QCL type (e.g., qcl-Type2), where the second QCL type is different from the first QCL type. The TCI state may indicate an additional PCI (e.g., additionalPCI'). The additional PCI may indicate a physical cell index (PCI) of SSB(s) when the first reference signal of the qcl-Type1 and the second signal of the qcl- Type2 are SSB(s). In such a case, if the additional PCI is present in the TCI state, this may refer to a PCI value configured in a list of additional PCI (e.g., PCI-ToAddModList) in serving cell configurations of a second cell. The wireless device may determine the second cell from the qcl-Type1 and / or the qcl-Type2 configurations. If qcl-Type1 and / or qcl-Type2 do not have parameter(s) of the second cell, the wireless device may determine the list of additional PCI from serving cell configurations of the cell (e.g., the serving cell).

[0398] The TCI state may comprise an index of a pathloss reference signal (PL-RS) (e.g , pathlossReferenceSignal-ld). The index of the PL-RS indicates a reference signal (one of a CSI-RS or an SSB) that would be used for determining pathloss for uplink transmissions (e.g., PUSCH, PUCCH and SRS). This field may refer to an element in a list of paVn\oss-ReferenceRSToAddModList of an active UL BWP of the cell. The TCI state may comprise parameter(s) of uplink power control (e.g., ul-PowerControl). The parameter(s) of uplink power control may configure power control parameters for the uplink transmissions (PUCCH, PUSCH, and SRS) for the TCI state. The TCI state may comprise a tag id pointer (e.g., tag-ld-ptr). The tag id pointer may indicate a TAG that is associated with the TCI state. A first value (e.g., nO) may indicate a first TAG with a tag-id parameter. A second value (e.g., n1) may indicate a second TAG with a tag-id2 parameter.

[0399] The one or more QCL parameters (e.g., QCL-Info) may comprise a cell index of a second cell (e.g., a cell). The second cell may transmit a reference signal for the qcl-Type1 or the qcl-Type2. In an example, if the cell index of the second cell is not present in the one or more QCL parameters, the wireless device may use a cell index of the cell (i.e., the serving cell where the TCI state is applied). The one or more QCL parameters may comprise an index of a bandwidth part. The index of the bandwidth part may indicate the bandwidth part of the second cell (if the cell is present) or the cell (i.e., the serving cell).

[0400] The one or more QCL parameters may indicate the reference signal for the qcl-Type1 or the qcl- Type2. The reference signal may be one of a CSI-RS or an SSB. The one or more QCL parameters may comprise an index to the CSI or the SSB. The one or more QCL parameters may indicate a QCL type using the reference signal. The QCL type may indicate one of {‘typeA’, ‘typeB’, ‘typeC, ‘typeD’}.Docket No.: 24-1240PCT

[0401] In an example, the PL-RS of the TCI may comprise an index of a SSB or a CSI-RS that is used for pathloss computation. Configuration parameters of the PL-RS may comprise a cell index of a third cell (e.g., additionalPCi') that is an index of the third cell transmitting the PL-RS.

[0402] FIG. 22 illustrates examples as per aspects of embodiments of the present disclosure.

[0403] A wireless device may support a plurality of TAGs for a serving cell. For example, the wireless device supports two TAGs for a serving cell. The serving cell may operate a multi-TRP scenario. A base station of the serving cell comprises a first TRP (TRP#1) and a second TRP (TRP#2). The wireless device may indicate to support the plurality of TAGs for the serving cell (e.g., via multiDCI-lnterCellMultiTRP- TwoTA).

[0404] The base station may transmit one or more RRC messages indicating / comprising parameters indicating a plurality of coreset pools. For example, the plurality of coreset pools comprise a first coreset pool and a second coreset pool. In an example, a first coreset pool (Coreset Pool#1 ) may correspond to the first TRP. In an example, a coreset pool index of the first coreset pool may be indicated via the one or more RRC messages. In an example, the wireless device may determine a coreset pool index of the first coreset pool as a predefined value (e.g., zero / 0) in response to not being indicated / configured with the coreset pool index via the one or more RRC messages. In an example, the one or more RRC messages may not indicate the first coreset pool. The wireless device may determine a coreset pool index of one or more coresets as a predetermined value, where the first coreset pool comprises the one or more coresets.

[0405] A second coreset pool (Coreset Pool#2), of the plurality of coreset pools, may correspond to the second TRP. In an example, a second coreset pool index of the second coreset pool may be indicated via the one or more RRC messages.

[0406] In an example, the first coreset pool may be associated with or be configured with or be tied with a first TCI state.

[0407] In an example, the second coreset pool may be associated with or be configured with or be tied with a second TCI state.

[0408] The wireless device may be equipped with a plurality of panels. In the example, the wireless device is equipped with a first panel (Panel#1 ) and a second panel (Panel#2). The first panel and the second panel may be a same or different.

[0409] In the specifications, a spatial domain filter parameter may be referred as a spatial domain filter, a spatial RX parameter, a spatial RX filter, a spatial parameter, and / or the like.

[0410] In an example, the first panel may be associated with or be configured with or be tied with a first spatial domain filter (Spatial Domain Filter #1).

[0411] In an example, the second panel may be associated with or be configured with or be tied with a second spatial domain filter (Spatial Domain Filter #2).Docket No.: 24-1240PCT

[0412] The one or more RRC messages may configure / indicate / comprise parameters of a first TAG and a second TAG for the serving cell. In an example, the first TAG of the plurality of TAGs may be associated with or be configured with or be tied with the first spatial domain filter (Spatial Domain Filter #1).

[0413] In an example, the second TAG of the plurality of TAGs may be associated with or be configured with or be tied with the second spatial domain filter (Spatial Domain Filter #2).

[0414] In an example, the wireless device may receive one or more second RRC messages (RRC message(s) in FIG. 22) indicating / comprising a TA offset (N_TA_offset) for a serving cell (e.g., a parameter of n-TimingAdvanceOffset for the serving cell). When the wireless device is provided / configured with a plurality of coreset pools for the serving cell, the one or more second RRC messages may indicate a second TA offset (e.g., a second N_TA_offset) for the serving cell (e.g., a second parameter of n- TimingAdvanceOffset2).

[0415] The wireless device may be provided / configured with the plurality of coreset pools. The plurality of coreset pools may comprise a first coreset pool with a first corset pool index being 0 (zero) and a second coreset pool with a second coreset pool index being 1 (one). The wireless device may be provided / configured with the plurality of coreset pools that comprise a first coreset without a first coreset pool index being configured via RRC signaling and a second coreset with a second coreset pool index being configured via RRC signaling as one / 1 .

[0416] The wireless device may apply / use the TA offset for one or more transmissions associated with or based on or with one or more first spatial domain filters. In an example, the wireless device may determine one or more transmission configuration / parameters based on the one or more first spatial domain filters. The one or more first spatial domain filters may be associated with or corresponding to one or more first TCI states. For example, the one or more first spatial domain filters comprise the first spatial domain filter (Spatial Domain Filter #1). The one or more first TCI states comprise the first TCI state. The first TCI state is associated with the first coreset pool (Coreset Pool #1).

[0417] In an example, the wireless device may apply / use the second TA offset for one or more second transmissions associated with or based on or with one or more second spatial domain filters. The one or more second spatial domain filters may be associated with or corresponding to one or more second TCI states. For example, the one or more second spatial domain filters comprise the second spatial domain filter (Spatial Domain Filter #2). The one or more second TCI states comprise the second TCI state. The second TCI state is associated with the second coreset pool (Coreset Pool #2).

[0418] In another example, the wireless device may receive the one or more RRC messages indicating / comprising the second TA offset for one or more second transmissions associated with or based on or with one or more second spatial domain filters. The one or more second spatial domain filters may be associated with or corresponding to one or more second TCI states or one or more SSB receptionsDocket No.: 24-1240PCT associated with / tied with / corresponding to a second physical cell index (e.g., physCell Id) that is different from a first physical cell index of the serving cell. The wireless device may apply / use the TA offset for the one or more first uplink transmissions associated with or based on or with one or more first spatial domain filters. The one or more first spatial domain filters may be associated with or corresponding to one or more first TCI states or one or more SSB receptions associated with / tied with / corresponding to a first physical cell index (e.g., physCellld) of the serving cell.

[0419] In an example, the TA offset may be used for the first timing advance group (TAG) for the serving cell. The second TA offset may be used for / associated with the second TAG for the serving cell. The wireless device may be configured / indicated with the first TAG and the second TAG for the serving cell. For example, a first ID of the first TAG is a first TAG-ID. A second ID of the second TAG is a second TAG-ID.

[0420] A MAC CE indicating one or more timing advance values (e.g., a MAC CE to update a timing advance value or a MAC to indicate an absolute timing advance value conveyed via a random access response) for one of the first TAG and the second TAG.

[0421] In an example, a RAR comprise a bit field that indicate / comprise a TAG identifier pointer (e.g., tag- Id-ptr) between a first value (e.g., 0) and a second value (e.g., 1). The first value may indicate / be associated with the one or more first TCI states and the second value may indicate / be associated with the one or more second TCI states, in response to a joint TCI state between downlink and uplink being enabled / configured / indicated (e.g., being configured with dl-OrJointTCI-StateList comprising the one or more first TCI states and the one or more second TCI states). The first value may indicate / be associated with the first TAG. The second value may indicate / be associated with the second TAG.

[0422] In another example, the first value may indicate / be associated with one or more first UL TCI states and the second value may indicate / be associated with one or more second UL TCI states, in response to a joint TCI state between downlink and uplink not being enabled / configured / indicated (or in response to being configured with a ul-TCI-State-List comprising the one or more first UL TCI states and the one or more second UL TCI states). In the example, the one or more first UL TCI states may be associated with or corresponding to the one or more first spatial domain filter parameters. The one or more second UL TCI states may be associated with or corresponding to the one or more second spatial domain filter parameters.

[0423] In another example, the first value may indicate / be associated with the one or more first spatial domain filters and the second value may indicate / be associated with the one or more second spatial domain filters, in response to.

[0424] In the examples, the first value may indicate / be associated with the first TAG. The second value may indicate / be associated with the second TAG. The first TAG may be associated with the one or more first TCI states (if dl-OrJointTCI-StateList is provided), the one or more first UL TCI states (if ul-TCI-State-Docket No.: 24-1240PCTList is provided). The second TAG may be associated with the one or more second TCI states (if dl- OrJointTCI-StateList is provided), the one or more second UL TCI states (if ul-TCI-State-List is provided).

[0425] In an example, a wireless device may receive one or more timing advance commands (TACs) for a TAG. The one or more timing advance command may be conveyed via one or more MAC CEs / PDSCHs. In an example, a first a MAC CE may indicate an identifier of a TAG (TAG ID) and a TAC. The TAC may comprise a timing advance value to adjust / update / apply a TA of the TAG with the TAG ID compared to a current TA for a serving cell. The wireless device may apply / update / adjust the TA of the TAG based on the timing advance value of the TAC and the TAG ID based on the first MAC CE. In an example, the wireless device may add the timing advance value to the current TA of the TAG.

[0426] In an example, a second MAC CE may indicate a first TAG identifier point (e.g., tag-ld-ptr = 0) or a second TAG identifier pointer (e.g., tag-ld-ptr = 1) for a serving cell and an absolute timing advance value for the serving cell. For example, based on a tag2 flag (e.g., tag2-flag) being set to FALSE (0), the first TAG identifier point with value 0 may correspond to the first TAG and the second TAG identifier point with value 1 may correspond to the second TAG. For example, based on the tag2 flag (e.g., tag2-flag) being set to TRUE (1), the first TAG identifier point with value 0 may correspond to the second TAG and the second TAG identifier point with value 1 may correspond to the first TAG.

[0427] In an example, when a wireless device is configured / indicated with a plurality of TAGs for a serving cell, based on a capability, the wireless device may reduce in duration a latter transmission using a first TAG (e.g., tag-ld-ptr = 0) of the plurality of TAGs to avoid overlapping with a former transmission using a second TAG (e.g., tag-ld-ptr = 1) of the plurality of TAGs.

[0428] In an example, a MAC CE of a timing advance update / command may comprise a TAG ID and a timing advance value. The wireless device may apply the timing advance value to a TAG with the TAG ID.

[0429] As shown in FIG. 22, the wireless device receives one or more RRC messages (RRC message(s)) indicating / comprising a first TA offset value (N_TA_offset) for a first TAG (TAG#1) and a second TA offset value (N_TA_offset2) for a second TAG (TAG#2). In the example, the first TAG is associated with a first coreset pool and a first spatial domain filter parameter. The second TAG is associated with a second coreset pool and a second spatial domain filter parameter. A first TCI state may be associated with the first coreset pool and the first spatial domain filter parameter. A second TCI state may be associated with the second coreset pool and the second spatial domain filter parameter.

[0430] The wireless device may determine a first TA (T_TA) for the first TAG based on the first TA offset and one or more timing advance values (for N_TA) for the first TAG via one or more MAC CEs and / or RARs. The wireless device may determine a second TA (T_TA2) based on the second TA offset and one or more second timing advance values (for N_TA2) for the second TAG via one or more second MAC CEs and / or RARs.Docket No.: 24-1240PCT

[0431] In an example, T_TA = (N_TA_offset + N_TA ) *Tc. T_TA2 = (N_TA_offset2 + N_TA2) *Tc.

[0432] The wireless device may transmit one or more uplink transmissions using / via the first spatial domain filter parameter based on the first TA (T_TA), where the one or more uplink transmission occurs T_TA before a reception timing of a downlink frame associated with the first coreset pool or the first TCI state. The downlink frame may correspond to an uplink frame of the one or more uplink transmissions.

[0433] The wireless device may transmit one or more second uplink transmissions using / via the second spatial domain filter parameter based on the second timing advance (T_TA2), where the one or more second uplink transmissions occur T_TA2 before a reception timing of a second downlink frame associated with the second coreset pool or the second TCI state. The second downlink frame may correspond to a second uplink frame of the one or more second uplink transmissions.

[0434] In the present disclosure, an on-demand SSB (OD-SSB) may refer FIG. 18 (and 19 - 21). A SSB that is not on-demand SSB may be referred as an always-on SSB or a normal SSB or a cell defining SSB or a non-cell defining SSB or a SSB. A base station may transmit one or more SSBs in a SSB burst via a cell. The base station may periodically transmit the SSB burst based on a periodicity. A SSB of the one or more SSBs in a SSB burst may be referred as a SSB with an index. Indexes of the one or more SSBs in the SSB burst may start from 0 to N-1 where N is a maximum number of SSBs in a single SSB burst in a given frequency range and / or subcarrier spacing of the cell.

[0435] One or more on-demand SSBs, if activated, may be transmitted periodically. One or more MAC CEs and / or DCIs may activate transmission on-demand SSB transmission. A wireless device may start receiving or expect to receive one or more on-demand SSBs in a next SSB burst (or a first SSB burst) after completing / finishing to apply the one or more MAC CEs and / or DCIs (or after finishing activation).

[0436] One or more second MAC CEs and / or DCIs may deactivate on-demand SSB transmission. If deactivated, the one or more SSBs of a SSB burst will be stopped or be skipped or not be transmitted via the cell. The wireless device may stop receiving or expect to stop receiving the one or more SSBs in a next SSB (or a first SSB burst) after completing / finishing to apply the one or more second MAC CEs and / or DCIs deactivating the on-demand SSBs.

[0437] For example, a periodicity of on-demand SSBs is 10msec if activated. The wireless device may receive a MAC CE activating the on-demand SSBs at a time N that becomes effective at N+m The wireless device may start to receiving one or more SSBs of the on-demand SSBs at K*10msec >= (N+m) / 10 where K is a smallest number satisfying the condition. Similarly, the wireless device may stop receiving one or more SSBs of the on-demand SSBs at K*10msec >= (N+m) / 10 where K is a smallest number satisfying the condition if the wireless device receives the deactivation MAC CE at the time N that are competeted in N+m. After activation, the wireless device may expect to measure or receive or receiveDocket No.: 24-1240PCT or measure one or more SSBs of the on-demand SSBs or one or more SSB bursts of the on-demand SSBs until a time instance B or receiving a deactivation indication as illustrated in FIG. 21 .

[0438] In the specification, an active (or activated, being transmitted, enabled, semi-persistently periodic, etc) on-demand SSB of a cell may be referred as an SSB that is an on-demand SSB and the SSB may be transmitted between a time instance A and a time instance B based on scenario / option 1 , 1 A, or 2 in FIG. 21 . In other time duration(s), the on-demand SSB of the cell may be referred as an inactive on-demand SSB, a deactivated on-demand SSB, inactive SSB, inactive on-demand SSB, deactive on-demand SSB, deactive SSB, skipped SSB, not present SSB, stopped SSB, and / or the like.

[0439] For example, if an on-demand SSB of a cell is configured with a scenario / option 3 with a small number N, the on-demand SSB may not be used for measurement based on a semi-persistent RS or a periodic RS (e.g., periodic L1-RSRP, RRM, beam failure related measurement, beam recovery related measurement). If the on-demand SSB of the cell is configured with a scenario / option 4 in FIG. 21 , the on- demand SSB of the cell may be referred as an NCD-SSB of the cell.

[0440] In the specification, an on-demand SSB or an on-demand SSB burst may be referred as or determined based on whether the on-demand SSB or the on-demand SSB burst may be adapted in terms of a periodicity of the on-demand SSB transmission (e.g., infinite periodicity may refer the on-demand SSB transmission is disabled / deactivated).

[0441] In the present disclosure, a cell comprises a SSB may refer that a base station transmits the SSB via / on the cell.

[0442] 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. The RS may be a SSB or a CSI-RS or a PRS. In an example, an on-demand SSB that is maintained as 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 semiperiodic 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) or a semiperiodic on-demand SSB or a semi-persistent on-demand 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) or a non-semi- periodic on-demand SSB or a non-semi-persistent on-demand SSB.Docket No.: 24-1240PCT

[0443] In an example, a wireless device may expect to receive periodically and continuously a RS that is a periodic RS. The periodic RS may not be activated via one or more downlink control commands (e.g ., MAC CE, DCI). The periodic RS may not be deactivated via one or more downlink control commands (e.g., MAC CE, DCI, RRC). In an example, a base station may transmit a periodic RS periodically for a serving cell of a wireless device regardless of the serving cell is activated or deactivated for the wireless device. An on- demand RS may be activated and / or deactivated via one or more downlink control commands (e.g., MAC CE, DCI, RRC).

[0444] Existing technologies face several challenges, particularly in managing timing advance group(s) (TAG(s)) that comprise cell(s) configured with on-demand reference signals (OD-RSs) (e.g., on-demand synchronization signal blocks (OD-SSBs)). The lack of dedicated methods and / or system for managing these TAG(s) may cause problems within networks. FIGS. 23 and 24A illustrate some of these problems.

[0445] FIG. 23 illustrates a scenario in which a wireless device (WD) 2310 communicates with a base station 2320 via cells 2330, 2340, 2350, and / or 2360. Cell 2330 may serve as a primary cell (PCell), and each of cells 2340, 2350, and 2360 may serve as a secondary cell (SCell). Each of these cells belong to a timing advance group (TAG). For example, PCell 2330 may belong to a TAG 2370 (e.g., a primary TAG (pTAG)), while SCell 2340, 2350, and 2360 may belong to a TAG 2380 (e.g., a secondary TAG (sTAG)).

[0446] WD 2310 may select a reference cell for each of TAGs 2370 and 2380. For example, WD 2310 may select PCell 2330 as the reference cell for TAG 2370. In one example, the selection may be based on PCell 2330 being the primary cell. WD 2310 may also select one of SCells 2340, 2350, and 2360 as the reference cell for TAG 2380. After selecting the reference cell for each TAG, WD 2310 may determine a downlink timing of each TAG based on measuring RS(s) from the reference cell for the TAG, and determine an uplink timing of each TAG based on the downlink timing. One example of the RSs are OD-RSs (e.g., OD-SSBs).

[0447] In an example, SCell 2360 is configured with OD-RS(s) 2390 and is selected by WD 2310 as the reference cell for TAG 2380. The reference cell for TAG 2380 is for measuring the downlink timing of TAG 2380. In this scenario, if OD-RS(s) 2390 of SCell 2360 are deactivated, WD 2310 may no longer measure the downlink timing of TAG 2380 based on OD-RS(s) 2390, creating a problem.

[0448] More specifically, due to WD 2310 not receiving OD-RSs 2390 from SCell 2360 after OD-RSs 2390 were deactivated, WD 2310 may not be able to update the downlink timing of TAG 2380. As a result, WD 2310 may rely on outdated downlink timing to set the uplink timing. This outdated uplink timing may then be used for uplink transmissions to base station 2320 via SCell 2340, 2350, and / or 2360, leading to poor reception quality at base station 2320.Docket No.: 24-1240PCT

[0449] The lack of dedicated method and / or system for managing TAG(s) that comprise cell(s) configured with OD-RSs may also be problematic in a scenario where a serving cell schedules a WD from multiple transmit / receive points (TRPs). This scenario is illustrated in FIG. 24A.

[0450] In FIG. 24A, a WD 2410 is served by two TRPs: a TRP 2420 and a TRP 2430. Although both TRPs belong to the same serving cell, they are associated with different TAGs. More specifically, TRP 2420 is associated with a TAG 2440 while TRP 2430 is associated with a TAG 2450. Each TRP transmits RS(s) 2460 or 2470 to WD 2410, enabling WD 2410 to measure the downlink timing for respective TAG. For example, RS(s) 2460 from TRP 2420 may be used to determine (e.g., measure, track, update, etc.) the downlink timing of TAG 2440. Similarly, RS(s) 2470 from TRP 2430 may be used to determine (e.g., measure, track, update, etc ) the downlink timing of TAG 2430.

[0451] In this scenario, if RS(s) 2470 from TRP 2430 are OD-RS(s) andand OD-RS(s) 2470 are later deactivated, WD 2410 may no longer be able to synchronize to TRP 2430 and determine (e.g., measure, track, update, etc.) the downlink timing for TAG 2450. More specifically, due to WD 2410 not receiving OD- RSs from TRP 2430 after those signals were deactivated, WD 2140 may be unable to update the downlink timing of TAG 2440. As a result, WD 2410 may rely on outdated downlink timing to set the uplink timing. This outdated uplink timing could then be used for transmissions to TRP 2430, leading to poor reception quality at TRP 2430.

[0452] In order to solve the above-described problems, embodiments of this disclosure provide methods and / or a system for managing TAG(s) that comprise cell(s) configured with OD-RSs.

[0453] More specifically, in one embodiment of this disclosure, there is provided a method comprising transmitting, by a wireless device, one or more uplink transmissions using a transmit timing which is based on a reference cell for a timing advance group (TAG), wherein a cell is selected as the reference cell, from among one or more cells of the TAG, based on whether the cell is configured with one or more on-demand reference signals (OD-RSs) .

[0454] In another embodiment, there is provided a method comprising transmitting, by a wireless device, one or more first uplink transmissions using a first timing advance group (TAG) associated with a first control resource set (CORESET) pool index for a serving cell and / or a second TAG associated with a second CORESET pool index for the serving cell, based on whether one or more on-demand reference signals (OD-RSs) associated with the second CORESET pool index are activated or deactivated.

[0455] The embodiments of this disclosure provide methods and a system for managing TAG(s) that comprise cell(s) configured with OD-RSs. The methods and system enable I) a wireless device to accurately measure the downlink timing of a TAG even when OD-RSs of an SCell belonging to the TAG are deactivated and / or (ii) a wireless device in an mTRP scenario to avoid wasting its resources and theDocket No.: 24-1240PCT resources of the network on performing uplink transmissions to a TRP configured with deactivated OD- RSs.

[0456] Referring back to FIG. 23, as previously explained, if SCell 2360, which is configured with OD- RS(s) 2390, is selected by WD 2310 as the reference cell for TAG 2380, the deactivation of OD-RS(s) 2390 would prevent WD 2310 from accurately determining the downlink timing of TAG 2380. Since the uplink timing - i.e., the timing for uplink transmission(s) - is based on the downlink timing, the deactivation of OD- RS(s) 2390 of SCell 2360 would ultimately hinder the ability of WD 2310 to determine the uplink timing (a.k.a., “transmit timing”). In order to solve this problem, according to an aspect of an embodiment of this disclosure, WD 2310 may re-select the reference cell in response to the deactivation of OD-RS(s) of the previously selected reference cell.

[0457] FIG. 25 shows an exemplary process 2500 for reselecting a reference cell of a TAG, according to an aspect of an embodiment of this disclosure. Process 2500 may begin with step 2502. Step 2502 comprises base station 2320 (e.g., gNB) transmitting to WD 2310 message(s) indicating TAG 2370 that comprises PCell 2330 and TAG 2380 that comprises SCells 2340, 2350, and 2360. In an example, base station 2320 may transmit the message(s) to WD 2310 via PCell 2330. It is important to note that the number and types of cells shown in FIGS. 23 and 25 are intended for illustrative purposes only and do not restrict the embodiments of this disclosure in any way.

[0458] The message(s) may be radio resource control (RRC) message(s) which comprise information about each serving cell of WD 2310. In one example, such information may be contained within an information element (IE) storing one or more configurations of a serving cell ( “Sen / ingCellConfkf). The IE may be used to configure WD 2310 with the serving cell.

[0459] The information about each serving cell of WD 2310 may indicate or comprise a serving cell ID (e.g., a serving cell index) identifying one of cells 2330-2360 and a TAG ID identifying a TAG to which the cell identified by the serving cell ID belongs. In FIG. 25, because SCells 2340-2360 belong to the same TAG, the information about SCells 2340-2360 may indicate or comprise the same TAG ID for all of SCells 2340-2360.

[0460] The information about each serving cell of WD 2310 may also indicate or comprise OD-RS configuration(s). The OD-RS configuration(s) of each serving cell of WD 2310 may indicate one or more of: i) a subcarrier spacing (SCS) of OD-RSs, ii) a physical cell identifier of OD-RSs, iii) time domain location information indicating on-demand RS burst (e.g., SSB burst), system frame number (SFN) offset, and / or half-frame index, iv) downlink transmission power of OD-RSs, v) a frequency location or a center frequency of OD-RSs, and / or vi) OD-RSs positions in a OD-RSs burst.

[0461] In an example, WD 2310 may receive two OD-RS configurations for SCell 2360 - first and second OD-RS configurations that are associated with the same BWP (e.g., the BWP indicated via aDocket No.: 24-1240PCT firstActiveDownlinkBWP-\d of ServingCellConfig) WD 2310 may expect or determine that: (1) a first SCS of OD-RS(s) in the first OD-RS configuration and a second SCS of OD-RS(s) in the second OD-RS configuration are the same; (2) a first frequency location of OD-RS(s) in the first OD-RS configuration and a second frequency location of OD-RS(s) in the second OD-RS configuration are the same; and / or (3) that a physical cell identifier (PCI) (e.g., phyCellld) of OD-RS(s) in the first OD-RS configuration and a physical cell identifier of OD-RS(s) in the second OD-RS configuration are the same.

[0462] In case the first PCI is different from the second PCI, WD 2310 may expect that one or more values corresponding to one or more other parameters in the first OD-RS configuration and the second OD- RS configuration are the same except the PCI parameter (e.g., the phyCellld parameter).

[0463] In one example, the value of a parameter may be absent (a.k.a., "missing” or “not present”) in the first and / or second OD-RS configurations (e.g., meaning no value is set for the parameter in either configuration). When this happens, WD 2310 may determine the missing value in the following ways:

[0464] 1 . If the value of the parameter is missing in either the first or second OD-RS configuration and present in one of them, WD 2310 may use the available value from that configuration for the missing one.

[0465] 2. If the value of the parameter is absent in both the first and second OD-RS configurations - meaning that the value of the parameter is missing in all configurations of SCell 2360), WD 2310 may derive the value of the parameter based on CD-SSB(s) of SCell 2360 (if available) or NCD-SSB(s) of an active BWP of SCell 2360 if those are available.

[0466] WD 2310 may anticipate receiving the value of the parameter for at least one of the first and second OD-RS configurations in response to SCell 2360 not being configured with CD-SSB(s) or NCD- SSB(s). For instance, WD 2310 may expect that the first phyCellld matches the physical cell identifier of SCell 2360. Similarly, WD 2310 may expect that the second phyCellld matches the second physical cell identifier associated with a coreset pool index = 1 of SCell 2360. In response to WD 2310 not being configured with a coreset pool with a coreset pool index value of 1 , WD 2310 may not expect to be configured with the first phyCellld or the second phyCellld. WD 2310 may determine the physical cell ID of SCell 2360 based on the PCI of the OD-RSs.

[0467] In one example, the first OD-RS configuration may be associated with a first BWP of SCell 2360, while the second OD-RS configuration may be associated with a second BWP of SCell 2360. WD 2310 may apply the first OD-RS configuration based on an active BWP being the first BWP, and may apply the second OD-RS configuration based on the active BWP being the second BWP.

[0468] Alternatively or additionally, WD 2310 may be configured with zero, one, or two OD-RS configurations for a BWP of SCell 2360. Having no OD-RS configurations for the BWP may mean that WD 2310 is not set up to use OD-RS(s) for that BWP If there is one OD-RS configuration, it may indicate that WD 2310 is configured with OD-RS(s) for that BWP, using a single PCI for SCell 2360. If there are two OD-Docket No.: 24-1240PCTRS configurations, this suggests that WD 2310 is set up with an inter-cell mTRP for the BWP of SCell 2360, with each OD-RS configuration corresponding to one TRP of the mTRP. The first and second OD-RS configurations may have different PCIs.

[0469] Referring back to FIG. 25, after receiving the message(s) in step 2502, process 2500 may proceed to step 2504. In this step, WD 2310 may select SCell 2360, from the cells included in TAG 2380 - i.e., SCells 2340, 2350, and 2360 -, as the reference cell for measuring the downlink timing of TAG 2380. The downlink timing of the TAG may be determined based on the timing of WD 2310 receiving OD-RS(s) 2390 via SCell 2360. Note that, in this disclosure, OD-RS(s) 2390 does not refer to any particular OD-RS(s) transmitted at a specific timing. Rather OD-RS(s) 2390 generally refers to any OD-RS(s) transmitted via SCell 2360.

[0470] After WD 2310 selects SCell 2360 as the reference cell, base station 2320 may deactivate OD- RS(s) 2390 of SCell 2360. In this scenario, in an optional step 2506, base station 2320 may transmit, to WD 2310, message(s) indicating the deactivation of OD-RS(s) 2390 of SCells 2360 - i.e., the deactivation of transmission of further OD-RS(s) via SCells 2360. In one example, the message(s) may be transmitted via PCell 2330

[0471] The message(s) may comprise an identifier identifying SCell 2360 and an indication of the deactivation of OD-RS(s) 2390. For example, the message(s) may contain serving cell ID #4 which identifies SCell 2360, along with one or more bits indicating that OD-RS(s) 2390 of SCell 2360 have been deactivated. The identifier and the deactivation indication may be included in a medium access control (MAC) control element (CE), in downlink control information (DCI) format, or in a RRC IE or message.

[0472] Instead of receiving the message(s) indicating the deactivation of OD-RS(s) 2390 of SCell 2360, WD 2310 may use a timer to determine whether OD-RS(s) 2390 of SCell 2360 are deactivated. For instance, WD 2310 may track the time since WD 2310 last received message(s) indicating activation of OD-RS(s) 2390. If WD 2310 finds that a specified time duration has elapsed since the time WD 2310 received the message(s) indicating the activation, WD 2310 may determine that OD-RS(s) 2390 have been deactivated. For example, WD 2310 may receive one or more configuration parameters indicating a value for the timer. WD 2310 may start / reset the timer in response to activating the OD-RS(s) of SCell 2360 or in response to receiving the message(s) indicating the activation. WD 2310 may reset / restart the timer in response to receiving one or more second message(s) to indicating activation of the OD-RS(s) of SCell 2360.

[0473] In another example, WD 2310 may use a counter to determine whether OD-RS(s) 2390 of SCell 2360 are deactivated. For instance, WD 2310 may count a number of instances of transmission occasions / transmissions of OD-RS(s) 2390. When the number of instances reaches a configured number (e.g., N), WD 2310 may determine that OD-RS(s) 2390 of SCell 2460 are deactivated. More specifically, inDocket No.: 24-1240PCT one example, WD 2310 may count the number of instances based on a periodicity of OD-RS(s) 2390 after the activation of OD-RS(s) 2390 (e.g., count one at OD-RSs resource / occasion based on a periodicity after activation, count two at OD-RSs resource / occasion based on two times of the periodicity after the activation, and so on).

[0474] In response to determining that OD-RS(s) 2390 of SCell 2360 are deactivated, process 2500 may proceed to step 2508. In this step, WD 2310 may reselect the reference cell for TAG 2380. In selecting the new reference cell, in one example, WD 2310 may choose the SCell having the lowest cell index or the lowest serving cell index among the SCells of TAG 2380. Alternatively, WD 2310 may select any SCell of TAG 2380 as the new reference cell.

[0475] In some scenarios, the selection of the new reference cell may subject to certain limitation(s). For instance, SCell 2360, which has deactivated OD-RS(s) 2390, may not be selected as the new reference cell. Additionally or alternatively, any SCell that is not configured with CD-RS(s) and / or any SCell with inactive OD-RS(s) may not be eligible as the new reference cell. Moreover, an SCell may be excluded from the selection under the following conditions: (1) if the SCell is not configured with either CD-RS(s) or NCD- RS(s) in an active BWP of the SCell; (2) if the SCell has inactive OD-RSs; and / or (3) if the SCell is already designated as a reference cell for a time / frequency tracking (for example, as indicated by referenceCell in frequencylnfoDL in the ServingCellConfigCommon IE of the SCell) and does not have active OD-RSs.

[0476] Note that there may be a scenario where an SCell in TAG 2380 is deactivated. In such case, WD 2310 may exclude the deactivated SCell from TAG 2380 or from being considered as a candidate for the new reference cell for TAG 2380.

[0477] In summary, if a TAG comprises a set of SCells and OD-RS(s) of the previously selected reference cell of the TAG are deactivated, WD 2310 may be allowed or configured to select a new reference cell from a subset of the remaining cells, ensuring that the previously selected reference cell is not included in this subset.

[0478] Referring back to FIG. 25, as a result of performing step 2508, SCell 2350 is selected as the new reference cell for TAG 2380.

[0479] In some cases, before step 2508 is performed, WD 2310 may determine that SCell 2360 is unavailable based on determining that OD-RS(s) 2390 of SCell 2360 are deactivated. Alternatively, WD 2310 may determine that SCell 2360 is unavailable based on determining that OD-RS(s) 2390 are deactivated and SCell 2360 does not comprise or transmit, or is not configured with CD-SSB and / or NCD- SSB. In these cases, process 2500 may proceed to step 2508 in response to determining that SCell 2360 is unavailable.

[0480] WD 2310 may identify different points in time as when SCell 2360 becomes unavailable For example, WD 2310 may determine that SCell 2360 is unavailable right after WD 2310 detects theDocket No.: 24-1240PCT deactivation of OD-RS(s) 2390. Alternatively, WD 2310 may conclude that SCell 2360 is unavailable after a specific time has elapsed since the OD-RS(s) 2390 were deactivated. As discussed earlier, WD 2310 may detect the deactivation of OD-RS(s) 2390 by either receiving messages that indicate the deactivation or by using a timer or counter.

[0481] In case WD 2310 is configured with multiple BWPs of SCell 2360, whether SCell 2360 is unavailable may be determined based on the active BWP of SCell 2360. In one example, consider a scenario where WD 2310 is configured with multiple BWPs of SCell 2360— specifically, a first BWP that has OD-RSs and a second BWP that does not have any OD-RSs. In an example, SCell 2360 is also not configured with any CD-RSs or NCD-RSs. At a certain time (T1 ), the first BWP is the active BWP of SCell 2360 and SCell 2360 is the reference cell for TAG 2380. If WD 2310 switches the active BWP from the first BWP to the second BWP at a later time (T2), WD 2310 may determine that SCell 2360 is unavailable based on that the second BWP - i.e. , the current active BWP - does not have any OD-RSs or active reference signals (e.g., SSB). This determination is made regardless of the status of the OD-RS (whether the OD-RS is active or inactive).

[0482] In summary, an SCell configured with OD-RS(s) is considered unavailable at WD 2310 when at least one OD-RS is configured by base station 2320, no CD-RS or NCD-RS is configured, and either the OD-RS of an active BWP is deactivated or current active BWP does not comprise any OD-RS.

[0483] As mentioned earlier, after WD 2310 determines that SCell 2360— the previously selected reference cell— is unavailable, WD 2310 may choose another SCell from TAG 2380 as the new reference cell. Importantly, even after the previous reference cell becomes unavailable and before a new reference cell is selected, WD 2310 may continue to transmit uplink signals through the SCells of TAG 2380. This decision is based on the accuracy of the transmit timing for TAG 2380, the accuracy of the downlink timing, and the timing advance accuracy requirements of WD 2310. Alternatively, WD 2310 may decide to stop or drop uplink transmissions through the SCells of TAG 2380.

[0484] Referring back to FIG. 25, after selecting SCell 2350 as the new reference cell, in step 2510, WD 2310 may receive RS(s), which may be either OD-RS(s) or non-OD-RS(s), from base station 2320 via SCell 2350. In step 2512, WD 2310 may measure the downlink timing of TAG 2380 based on the received RS(s). The measurement of the downlink timing may allow WD 2310 to determine the transmit timing of TAG 2380 based on the measured downlink timing. After determining the transmit timing of TAG 2380, in step 2514, WD 2310 may transmit uplink signal(s) (i.e., performing uplink transmissions or transmitting uplink transmissions) using the transmit timing determined in step 2512.

[0485] In the aspect of the embodiment shown in FIG. 25, the problem of reference cell selection, discussed above, is addressed by ensuring that WD 2310 reselects the reference cell in case OD-RS(s) ofDocket No.: 24-1240PCT the previously selected reference cell are deactivated and excludes the cell with deactivated OD-RS(s) from being considered as a candidate for the new reference cell.

[0486] In a different aspect of this embodiment, however, an SCell with OD-RSs and without any cell defining RSs (CD-RSs) (e.g., CD-SSB) may not even considered as a candidate for the reference cell. In other words, regardless of whether OD-RSs of an SCell are deactivated or not, such SCell may not be selected as the reference cell if the SCell is without any CD-RSs.

[0487] FIG. 26 shows a process 2600 for selecting a reference cell according to the different aspect of the embodiment. Process 2600 may begin with step 2602. Step 2602 comprises base station 2320 (e.g., gNB) transmitting to WD 2310 message(s) indicating i) pTAG 2379 which comprises PCell 2330 and ii) sTAG 2380 which comprises cells 2330-2360. Base station 2320 may transmit the message(s) to WD 2310 via PCell 2330 or via one or more of SCells 2340-2360. It is important to note that the number and types of cells shown in FIGS. 23 and 26 are intended for illustrative purposes only and do not restrict the embodiments of this disclosure in any way.

[0488] Like the message(s) transmitted in step 2502 of process 2500, the message(s) transmitted in step 2602 may be radio resource control (RRC) message(s) including information about each serving cell of WD 2310. In one example, such information may be contained within the information element (IE) “Sen / ingCellConfig" and / or the IE ‘ ServingCellConfigCommon" .

[0489] As shown in FIG. 26, the information about each serving cell of WD 2310 may indicate (e.g., include, comprise, etc.) a serving cell ID (e.g , a serving cell index) identifying one of cells 2330-2360 and a TAG ID identifying a TAG to which the cell identified by the serving cell ID belongs. In one example, the ServingCellConfig IE may comprise an IE tag-IE which identifies the TAG to which the corresponding cell belongs. In FIG. 26, because all SCells 2340-2360 belong to the same TAG - i.e. , TAG 2380 -, the information may comprise the same TAG ID for all of cells 2340-2360.

[0490] After receiving the message(s) in step 2602, process 2600 may proceed to step 2604. In this step, WD 2310 may identify that RS(s) 2390 - i.e., the RS(s) transmitted by base station 2320 via SCell 2360 - are OD-RS(s). In contrast, the RSs sent through the other SCells— specifically, cells 2340 and 2350— are not OD-RSs.

[0491] In addition to identifying that RS(s) 2390 are OD-RS(s), in step 2604, WD 2310 may also determine that SCell 2360 is not configured with any CD-RS(s). There are different ways for WD 2310 to determine whether SCell 2360 is configured with any CD-RS(s). In one example, WD 2310 may determine that SCell 2360 is configured with CD-RS(s) based on parameter(s) of the ServingCellConfigCommon IE of SCell 2360. The parameter(s) may comprise one or more of: i) a frequency location of CD-RSs (e.g., absoluteFrequencySSB IE), II) a periodicity of CD-RSs (e.g., ssb-Periodicity IE), Hi) CD-RS positions in a CD-RS burst (e.g., ssb-PositionsinBurst IE); and / or iv) an indication of a reference cell (e.g., referenceCellDocket No.: 24-1240PCTIE included in FrequencylnfoDL IE). Based on whether the parameter(s) are configured for an SCell, WD 2310 may determine whether the SCell is configured with CD-RS(s). For example, if any one or more of the parameters (i)-(iii) are configured for an SCell, WD 2310 may determine that the SCell is configured with CD-RS(s). In another example, if the paragraph (iv) is configured for an SCell, WD 2310 may determine that the SCell is not configured with CD-RS(s).

[0492] In addition to determining whether SCell 2360 is configured with OD-RS(s) and / or CD-RS(s), in step 2604, WD 2310 may also determine whether SCell 2360 is configured with NCD-RS(s). Like CD- RS(s), there are different ways for WD 2310 to determine whether an SCell is configured with any NCD- RS(s). For example, WD 2310 may determine that an SCell is configured with NCD-RS(s) based on parameter(s) of a BWP of the SCell (e g., BWP-DownlinkDedicated IE). Here, the BWP may be an active BWP of the SCell. The parameter(s) of the BWP may comprise one or more of: i) a frequency location of NCD-RS(s) (e.g., absoluteFrequencySSB IE), ii) a periodicity of NCD-RS(s) {e.g., ssb-Periodicity IE), and / or ill) NCD-RS positions in an NCD-RS burst {e.g., ssb-PositionsInBurst IE).

[0493] After WD 2310 determines that SCell 2360 is configured with OD-RS(s) and not with any CD- RS(s), process 2600 may proceed to step 2606. Alternatively, after WD 2310 determines that SCell 2360 is configured with OD-RS(s) and not with any CD-RS(s) or NCD-RS(s), process 2600 may proceed to step 2606. In step 2606, WD 2310 may select a reference cell from the cells included in TAG 2380, excluding SCell 2360 because of its configuration. As a result, as shown in FIG. 26, WD 2310 may select a reference cell from SCells 2340 and 2350. In summary, if a TAG comprises a set of cells and one of the cells satisfies the condition of being configured with OD-RSs and not with CD-RSs (and / or NCD-RSs), the reference cell will be selected from a subset of the remaining SCells, ensuring that the cell satisfying the condition is excluded from the selection.

[0494] As explained above, in process 2600, SCell 2360 is not considered as a candidate for the reference cell for TAG 2380. However, there may be instances where WD 2310 is set by default to select any of the cells in TAG 2380 - SCells 2340, 2350, and 2360 - as the reference cell for TAG 2380. Thus, according to an aspect of the embodiment, if WD 2310 selects SCell 2360 as the reference cell, WD 2310 may reselect the reference cell for TAG 2380 if WD 2310 determines that SCell 2360 meets the criteria of being configured with OD-RSs and not with CD-RSs (and / or NCD-RSs) (i.e., SCell 2360 is an SSB-less cell).

[0495] In an aspect of the embodiment, WD 2310 may exclude SCell 2360 from being considered as a candidate for the reference cell for TAG 2380 if WD 2310 determines that SCell 2360 is unavailable. Alternatively, if SCell 2360 was previously chosen as the reference cell and is later found to be unavailable, WD 2310 may select a new reference cell for TAG 2380.Docket No.: 24-1240PCT

[0496] There are different ways of WD 2310 to determine the availability of SCell 2360. For instance, WD 2310 may conclude that SCell 2360 is unavailable if SCell 2360 is configured with OD-RS(s) and not with CD-RS(s) (and / or NCD-RS(s)). Specifically, WD 2310 may find SCell 2360 unavailable if SCell 2360 is not configured with CD-RS(s) or NCD-RS(s) in the active BWP of SCell 2360. For example, if SCell 2360 has NCD-RS(s) (e.g, NCD-SSB(s)) in its first BWP and then switches to its second BWP that lacks or is not configured with any NCD-RS(s), WD 2310 may determine that SCell 2360 is unavailable if SCell 2360 is not configured with any CD-RS(s).

[0497] After selecting SCell 2350 as a reference cell (or a new reference cell) for TAG 2380, in step 2608, WD 2310 may receive RS(s), which may be either OD-RS(s) or non-OD-RS(s), from base station 2320 via SCell 2350. In step 2610, WD 2310 may measure the downlink timing of TAG 2380 based on when WD 2310 received the RS(s) via SCell 2350. Here, the downlink timing of TAG 2380 may be defined as the time when the first detected path (in time) of the corresponding downlink frame included in the RS(s) is received from base station 2320 via SCell 2350.

[0498] The measurement of the downlink timing may allow WD 2310 to determine the transmit timing of TAG 2380 based on the measured downlink timing. After determining the transmit timing of TAG 2380, in step 2612, WD 2310 may transmit uplink signal(s) (i.e., performing uplink transmissions or transmitting uplink transmissions) using the transmit timing determined in step 2512.

[0499] By excluding any SCell that has OD-RS(s) and lacks CD-RS(s) (and / or NCD-RS(s)) from consideration as a reference cell, the above discussed problem of inadvertently selecting an SCell with deactivated OD-RS(s) may be effectively avoided. Additionally or alternatively, to avoid selecting an SCell with deactivated OD-RS(s) as the reference cell, a TAG (e.g., sTAG) may be required to comprise at least one cell with non-OD-RS(s) (e.g., legacy SSB such as a periodic SSB and / or a semi-periodic SSB). In other words, WD 2310 may not be required to handle a sTAG if the sTAG only comprises SCell(s) without any CD-RS(s) (e g, CD-SSB(s)) or SSB-less SCell(s).

[0500] In an aspect of the embodiments, instead of completely excluding an SCell that has OD-RS(s) and lacks CD-RS(s) from being considered as a reference cell for a TAG, a lower priority may be assigned to that SCell. Conversely, cells that do not meet this condition (those configured with OD-RS(s) and without CD-RS(s)) may be given a higher priority. Then, in step 2508, WD 2310 may select the reference cell while taking into account the different priorities assigned to the cells within the TAG.

[0501] Although FIG. 23 shows that pTAG 2370 contains only PCell 2330, it’s possible that pTAG 2370 actually comprises multiple SCells in addition to the PCell. For instance, pTAG 2370 may comprise PCell 2330, a first SCell, and a second SCell. If PCell 2330 becomes unavailable— for example, if WD 2330 fails to receive any RS(s) from it for a specified time (like 1280 ms)— then WD 2330 may choose a new reference cell for TAG 2370. When selecting this new reference cell, WD 2330 may use the same criteriaDocket No.: 24-1240PCT as outlined in step 2606 of process 2600. Specifically, if the second SCell has OD-RS(s) and lacks CD- RS(s) (and / or NCD-RS(s)), while the third SCell has CD-RS(s) (and / or NCD-RS(s)), WD 2330 may select the third SCell as the new reference cell. If there are multiple SCells in pTAG 2370 that are configured with CD-RS(s) (and / or NCD-RS(s)), WD 2330 may choose the SCell with the lowest cell index as the new reference cell.

[0502] As discussed earlier with respect to FIG. 24A, the lack of dedicated methods and / or system for managing TAG(s) including cell(s) with OD-RSs may pose challenges during an inter-cell multi-TRP operation.

[0503] In the inter-cell multi-TRP operation illustrated in FIG. 24A, the serving cell of WD 2410 may schedule WD 2410 from two TRPs: TRPs 2420 and 2430 The serving cell may have a primary physical cell identifier (PCI), also known as the “serving cell PCI,” and an additional PCI. As shown in FIG. 24B, TRP 2420 may be associated with the serving cell PCI, while TRP 2430 may be associated with the additional PCI.

[0504] TRP 2420 may be configured to transmit RS(s) 2460 corresponding to the serving cell PCI, and TRP 2430 may be configured to transmit RS(s) 2470 corresponding to the additional PCI. In an example, a SSB or a RS is scrambled or sequence of the SSB / RS is generated based on a PCI based on the SSB or the RS being associated with the PCI.

[0505] In the inter-cell multi-TRP operation depicted in FIG. 24A, WD 2410 may be set up with a list of TCI states for the serving cell. For instance, as shown in FIG. 24B, this list may comprise a TCI state 2452 indicating i) an index of RS(s) 2460 for first QCL-info configuration(s) and / or ii) the serving cell PCI. The list may also comprise a TCI state 2454 indicating i) an index of RS(s) 2470 for second QCL-info configuration(s) and / or ii) the additional PCI. In this context, the additional PCI may be indicated (e.g . , identified) by a parameter value (e.g., additionalPC!) found (e.g., indicated or included) in TCI state 2454.

[0506] The serving cell PCI may be used and / or applied for the first QCL-info configuration(s) and / or RS(s) 2460 while the additional PCI may be used and / or applied for the second QCL-info configuration(s) and / or RS(s) 2470.

[0507] Furthermore, as shown in FIG. 24B, WD 2410 may be configured with a plurality of CORESETS for the serving cell. These CORESETS may comprise a CORESET 2462 which indicates, is configured with, and / or comprises a CORESET pool index 2472 of a first CORESET pool and / or a TCI-state identifier identifying TCI state 2452. For example, CORESET pool index 2472 of the first CORESET pool is zero (0). Based on TCI state 2452 and CORESET 2462, WD 2410 may communicate with TRP 2420.

[0508] The plurality of CORESETS may also comprise a CORESET 2464 which indicates, is configured with, and / or comprises a CORESET pool index 2474 of a second CORESET pool and / or a TCI-state identifier identifying TCI state 2454. In an example, CORESET pool index 2474 of the second CORESETDocket No.: 24-1240PCT pool is one (1). Based on TCI state 2454 and CORESET 2464, WD 2410 may communicate with TRP 2430.

[0509] Additionally, as shown in FIG. 24B, WD 2410 may be configured with multiple TAGs for the serving cell, including a TAG 2482 and a TAG 2484. TCI state 2452 may comprise a flag (e.g . , tag-ld-ptr) indicating TAG 2482, and TCI state 2454 may comprise a flag indicating TAG 2474. More specifically, in one example, the flag having the value of zero (0) may indicate TAG 2482 while the flag having the value of one (1) may indicate TAG 2484.

[0510] Based on the flag indicating TAG 2482, WD 2410 may establish the downlink timing for TAG 2482 using RS(s) 2460, which are linked to CORESET 2462, CORESET pool index 2472, the serving cell PCI, and / or TCI state 2452. Once the downlink timing for TAG 2482 is determined, WD 2410 may also establish the corresponding uplink timing for TAG 2482. WD 2410 will then use this uplink timing to transmit uplink transmissions to TRP 2420.

[0511] Similarly, based on the flag indicating TAG 2484, WD 2410 may establish the downlink timing for TAG 2484 using RS(s) 2470, which are linked to CORESET 2464, CORESET pool index 2474, the additional PCI, and / or TCI state 2454. Once the downlink timing for TAG 2484 is determined, WD 2410 may also establish the corresponding uplink timing for TAG 2484. It will then use this uplink timing to transmit uplink transmissions to TRP 2430.

[0512] During the inter-cell multi-TRP operation illustrated in FIG. 24A, there may be a scenario where RS(s) transmitted by TRP 2430 are OD-RS(s), but later, TRP 2430 deactivates OD-RS(s), meaning that TRP 2430 no longer transmits OD-RS(s) to WD 2410. In this scenario, WD 2410 cannot synchronize to TRP 2430. Consequently, continuously monitoring CORESET 2464 and transmitting uplink transmission(s) using TCI state 2454 may lead to a waste of resources of WD 2410 and network resources.

[0513] In order to address these problems, according to an aspect of an embodiment of this disclosure, a process 2700 shown in FIG. 27 is provided for performing an inter-cell multi-TRP operation. It is important to note that FIG. 27 does not depict every step involved in the process; rather, it highlights only those steps that are directly relevant to the embodiment. Process 2700 may begin with step 2702 and / or step 2704.

[0514] Step 2702 comprises WD 2410 receiving, from TRP 2420, RS(s) 2460 which may be either OD- RS(s) and / or non-OD-RS(s). RS(s) 2460 may be associated with one or more of: the serving cell PCI, TCI state 2452, and / or CORESET 2462 having CORESET pool index 2472 of zero (0). Step 2704 comprises WD 2410 receiving, from TRP 2430, RS(s) 2470 which may be OD-RS(s). RS(s) 2470 may be associated with one or more of: the additional PCI, TCI state 2454, CORESET 2464 having CORESET pool index 2474 of one (1). Note that step 2704 may occur either before or after step 2702. Alternatively, both steps may be performed simultaneously. As noted earlier, an example of RS is synchronization signal block (SSB) which may or may not comprise a physical broadcast channel (PBCH).Docket No.: 24-1240PCT

[0515] After receiving RSs 2460 and 2470 from TRPs 2420 and 2430, process 2700 may proceed to step 2706. In this step, WD 2410 may measure the downlink timing (i.e., the first timing of receiving a downlink frame) associated with TRP 2420 and TAG 2482, using RS(s) 2460 received from TRP 2420. This downlink timing may also be linked to one or more of: the serving cell PCI, TCI state 2452, CORESET 2462 with CORESET pool index 2472, and / or TAG 2482. For simplicity, this downlink timing will be referred to as “the downlink timing associated with TRP 2420.”

[0516] Additionally, WD 2410 may measure the downlink timing associated with TRP 2430 and TAG 2484, using RS(s) 2470 received from TRP 2430. Like the downlink timing associated with TRP 2420, this downlink timing may also be linked to one or more of: the additional cell PCI, TCI state 2454, CORESET 2464 with CORESET pool index 2474, and / or TAG 2484. For simplicity, this downlink timing will be referred to as “the downlink timing associated with TRP 2430.”

[0517] Note that measuring the downlink timings for TRP 2420 and TRP 2430 may be done independently and separately. Also these measurements may occur simultaneously or at different times.

[0518] Also note that, in this disclosure, the expression “associated with a TRP” may be replaced with “associated with a CORESET pool index.” Here, the CORESET pool index is associated with the TRP.

[0519] The downlink timing associated with TRP 2420 may be defined and / or determined based on the reception time of the first detected path (in time) of one of RS(s) 2460. In other words, this downlink timing may be defined as the moment when the first detected path of the corresponding downlink frame in RS(s) 2460 is received from TRP 2420.

[0520] Similarly, the downlink timing associated with TRP 2430 may be defined and / or determined based on the reception time of the first detected path (in time) of one of RS(s) 2470. In other words, this downlink timing may be defined as the moment when the first detected path of the corresponding downlink frame in RS(s) 2470 is received from TRP 2430.

[0521] After measuring the downlink timings of TAGs 2482 and 2484, WD 2410 may determine (e.g., derive) the transmit timings, also known as, “UE transmit timings,” for these TAGs based on the measured downlink timings. For instance, WD 2410 may determine the transmit timing for TAG 2482 using its measured downlink timing of TAG 2482 and the timing advance (TA) of TAG 2482. Similarly, WD 2410 may determine (e.g , derive) the transmit timing for TAG 2484 using its measured downlink timing of TAG 2484 and the TA of TAG 2484.

[0522] The transmit timing for TAG 2482 occurs before the downlink timing for TAG 2482, and the difference between the transmit and downlink timings of TAG 2482 may be equal to or determined based on the TA of TAG 2482. Similarly, the transmit timing for TAG 2484 occurs before the downlink timing for TAG 2484, and the difference between the transmit and downlink timings of TAG 2484 may be equal to or determined based on the TA of TAG 2484.Docket No.: 24-1240PCT

[0523] Referring back to FIG. 27, after performing step 2706, process 2700 may proceed to steps 2708 and 2710. In steps 2708 and 2710, WD 2410 may transmit uplink transmissions to TRPs 2420 and 2430 using the determined transmit timings. For example, in step 2708, WD 2410 may use the transmit timing - i.e., the uplink frame timing - of TAG 2482 to transmit uplink transmission(s) using TCI state 2452. Similarly, in step 2710, WD 2410 may use the uplink frame timing to transmit uplink transmission(s) using TCI state 2454.

[0524] As mentioned earlier, after receiving OD-RS(s) 2470 from TRP 2430, there may be a scenario where transmission of further OD-RS(s) 2470 from TRP 2430 is deactivated. In this case, TRP 2430 or a different network node such as TRP 2420 may transmit to WD 2410 message(s) indicating the deactivation of OD-RS(s) of TRP 2430. For instance, in optional step 2712, TRP 2430 may transmit message(s) indicating the deactivation of OD-RS(s) of TRP 2430 (hereinafter "deactivation indication message(s)” - a.k.a., “DI message(s)”).

[0525] The DI message(s) may comprise a medium access control (MAC) control element (CE) comprising a field that indicates the deactivation of OD-RS(s) 2470 - i.e., the OD-RS(s) associated with the additional PCI, CORESET 2464 with CORESET index 2474 of 1. More specifically, in one example, the MAC CE may include a field containing RRC configuration, and the RRC configuration may indicate the deactivation of OD-RS(s) 2470. Alternatively, the DI message(s) may comprise downlink control information (DCI) indicating the deactivation of OD-RS(s) 2470. The DCI may be a UE-specific DCI format, a group- common DCI format or a cell-specific DCI format. The DCI may be scrambled by C-RNTI, P-RNTI, and / or the like. The DCI may be based on a DCI format 1_0, 1_1, 1_2, 1_3, 2_9, etc. .

[0526] The DI message(s) may comprise a RRC message indicating a state (e.g., activated / deactivated) of the OD-RS(s) 2470 as ‘deactivated’ to indicate the deactivation of OD-RS(s) 2470.

[0527] The MAC CE or DCI may indicate the deactivation of OD-RS(s) 2470 in several ways.

[0528] In the first example, the MAC CE or DCI may comprise a bit for each serving cell with additional PCI. This bit may indicate whether RS(s) associated with both the serving cell PCI and the additional PCI of the serving cell are activated or deactivated. This bit may indicate whether RS(s) associated with both the CORESET pool index 2472 and 2474, and / or both the TAG 2482 and TAG 2484 of the serving cell are activated or deactivated. More specifically, the MAC CE or the DCI may comprise a bitmap of a certain size, which may be determined by the maximum number (e.g., 8, 32, etc.) of serving cells and / or carriers that a wireless device may be configured with. Each bit in the bitmap may correspond to a particular index associated with a particular serving cell, with the value of each bit indicating activation or deactivation of OD-RS(s) (or enabling and / or activating OD-RS(s)) of that serving cell.

[0529] FIG. 28 shows an example of MAC CE or DCI that indicates activation and / or deactivation of OD- RS(s) of three serving cells of a WD. In FIG. 28, the MAC CE or DCI contains three bit fields - 2802, 2804,Docket No.: 24-1240PCT and 2806. Bit field 2802 has an index value of 0, representing the first serving cell of the WD or a serving cell with a serving cell index value of 0. Similarly, bit field 2804 has an index value of 1 and bit field 2806 has an index value of 3, indicating the second (e.g., a second serving cell with a second serving cell index value of 1) and third (e.g., a third serving cell with a third serving cell index value of 2) serving cells, respectively.

[0530] In FIG. 28, the bit value of bit field 2802 is 1 , which indicates that OD-RS(s) of the first serving cell or the serving cell with the serving cell index value of 0 are activated. In contrast, the bit values of bit fields 2804 and 2806 are both 0, indicating that the OD-RSs of the second and third serving cells are deactivated.

[0531] In summary, in this first example, the MAC CE or DCI may comprise a single bit for each serving cell, indicating the activation and / or deactivation of OD-RS(s) of the serving cell. Thus, if this MAC CE or the DCI format is used during the inter-cell multi-TRP operation shown in FIG. 24A, the MAC CE or the DCI format may indicate the activation or deactivation of both RSs 2460 and 2470 together. In other words, this approach may not allow for the separate indication of the activation or deactivation of RSs 2460 from that of RSs 2470, as both are associated with the same serving cell. It is noted that the MAC CE or DCI may comprise a M-bit size bit(s) for each serving cell, indicating activation / activation of one or more OD-RS configurations of the serving cell, where M is equal to or greater than 1 .

[0532] In a second example, the MAC CE or DCI may comprise a bit, for one or more serving cells configured with additional PCI(s) and / or OD-RS(s). The bit may activate each OD-RS(s) of each serving cell of the one or more serving cells (e.g., by indicating one (1 or TRUE)). The bit may deactivate each OD- RS(s) of the each serving cell (e.g., by indicating zero(0)). The MAC CE or DCI may comprise one or more bits, where each bit activates / deactivates one or more OD-RS(s) of one or more serving cells of a plurality of serving cells. WD 2410 may be configured with one or more groups of serving cell(s) of the plurality of serving cells, where each bit corresponds to each group of the one or more groups. In the example, the one or more serving cells may be configured with OD-RS(s) and / or configured with a multi-TRP inter-cell operation (e.g., each is configured with an additional PCI and / or a CORESET pool index value of 1. The plurality of serving cells may be configured with OD-RSs and / or a multi-TRP inter-cell operation.

[0533] In a second example, the MAC CE or DCI may comprise a bit, for the additional PCI of each serving cell, indicating whether RS(s) of the additional PCI of the serving cell are activated or deactivated. For example, the MAC CE or DCI may comprise a bit for the serving cell of WD 2410, indicating whether OD-RS(s) 2470 - i.e., OD-RS(s) for the additional PCI, are activated or deactivated.

[0534] In a third example, the MAC CE or DCI may comprise two bits for each serving cell (i.e., for each serving index), indicating i) activation or deactivation of OD-RS(s) associated with the serving cell PCI of the serving cell and II) activation or deactivation of OD-RS(s) of the additional PCI of the serving cell. For example, the MAC CE or DCI may comprise two bits for the serving cell of WD 2410. One of the two bitsDocket No.: 24-1240PCT may indicate activation or deactivation of OD-RS(s) 2460 - i.e. , the OD-RS(s) associated with the serving cell PCI - and OD-RS(s) 2470 - i.e., the OD-RS(s) associated with the additional PCI. It is noted that the MAC CE or DCI may comprise a M-bit size bit(s) for the serving cell PCI of the serving cell and additional N-bit size bit(s) for the additional PCI of the serving cell, where M and N is equal to or greater than 1 .

[0535] In a fourth example, the MAC CE or DCI may comprise two bits for each serving cell. One of the two bits may indicate activation or deactivation of OD-RS(s) and another bit may indicate whether the indication is for the additional PCI only or for both the serving cell PCI and the additional PCI. For example, the MAC CE or DCI may comprise two bits for the serving cell of WD 2410. One of the two bits may indicate that OD-RS(s) are deactivated and another bit may indicate that the deactivation indication is only for the additional PCI - i.e., only for OD-RS(s) 2470.

[0536] Based on the received DI message(s), in step 2714, WD 2410 may determine that OD-RS(s) 2470 - i.e., the OD-RS(s) associated with the additional PCI - are deactivated.

[0537] Instead of receiving the DI message(s), WD 2410 may use a timer to determine whether OD-RS(s) 2470 are deactivated. For instance, WD 2410 may track the time since WD 2410 last received one or more messages indicating the activation of OD-RS(s) 2470. If WD 2410 finds that a specified duration has elapsed since the time WD 2410 received the message(s) indicating the activation, WD 2410 may determine that OD-RS(s) 2470 have been deactivated. For example, WD 2410 may start a timer, to track the time, after the activation of OD-RS(s) 2470 and / or activation the serving cell. The timer may run during a configured duration (e.g., a OD-RSDeactivationTimer). WD 2410 may redetermine the timer expired upon the configured duration has elapsed. In response to the expired timer, WD 2410 may determine that OD- RS(s) 2470 are deactivated. In an example, based on determining that OD-RS(s) 2470 are deactivated, WD 2410 may skip / stop uplink transmission(s) using TCI state 2454 associated with TAG 2482.

[0538] For example, WD 2410 may determine, in response to determining OD-RS(s) 2470 are deactivated, that an uplink synchronization of TAG 2482 is lost. For example, WD 2410 may determine, in response to determining OD-RS(s) 2470 are deactivated, that a time alignment timer (e.g., timeAlignmentTimer) associated with (or configured with) TAG 2482 is expired or stopped. Based on the time alignment timer of TAG 2482 is expired / stopped, WD 2410 may clear any configured downlink assignment, that is associated with TCI state 2454 or corresponding PUCCH resources is associated with TCI state 2454, clear any configured uplink grant associated with TCI state 2454, and / or clear any PUSCH resource for semi-persistent CSI reporting associated with TCI state 2454. WD 2410 may maintain a timing advance of TAG 2482. WD 2410 may consider an uplink synchronization of TAG 2482 is lost.

[0539] In an example, WD 2410 may release or deactivate one or more random access resources associated with additional PCI of the serving cell, based on step 2714.Docket No.: 24-1240PCT

[0540] In an example, WD 2410 may release or deactivate one or more PUCCH resources associated with TCI state 2454 indicating TAG 2484 (e.g., associated with TAG 2484 by indicating tag-ld-ptr = 1).

[0541] In an example, WD 2410 may release or deactivate TAG 2484. WD 2410 may fallback or switch to a single TA operation for the serving cell (e.g., TAG 2482 is only available TAG of the serving cell). After WD 2410 determines that OD-RS(s) 2470 are deactivated, process 2700 may proceed to step 2716. In this step, WD 2410 may receive RS(s) (either OD-RS(s) or non-OD-RS(s)) from TRP 2420. Although FIG. 27 indicates that step 2716 is performed after steps 2710, 2712, and 2714, step 2176 can actually be performed before any one of the steps.

[0542] After receiving the RS(s) from TRP 2420, process 2700 may proceed to step 2718. In step 2718, WD 2410 may use the received RS(s) to determine the downlink timing of TAG 2482 In this step, WD 2410 may also read information about the available CORESET(s) from the RS(s), monitor those CORESET(s), and decode the DCI carried within the CORESET(s). Based on the measured downlink timing, WD 2410 may derive the transmit timing of TAG 2482. Then, in step 2720, WD 2410 may transmit uplink signal(s) (i.e., performs / transmits uplink transmission(s)) to TRP 2420 using the derived transmit timing

[0543] In contrast to TRP 2420, WD 2410 may not receive any OD-RS(s) from TRP 2430 because of the deactivation of OD-RS(s). In this situation, according to an aspect of an embodiment, WD 2410 may choose to skip monitoring CORESET(s) 2464 - i.e., the CORESET(s) associated with TRP 2430 or CORESET pool index 2474. Additionally, WD 2410 may also skip transmitting any uplink signal to TRP 2430 using TCI state 2454, thus preventing unnecessary use of network resources.

[0544] In the example, WD 2410 may skip monitoring a CORESET that is associated with a SSB index indicating a SSB of OD-RS(s) 2470. For example, WD 2410 may skip monitoring a CORESET that is associated with a TCI state indicating a tag-ld-ptr value of one (1) (i.e., indicating TAG 2484). For example, WD 2410 may skip monitoring a CORESET that is associated with a common search space and associated with a CORESET pool with a CORESET pool index value of one (1 ).

[0545] In the example, WD 2410 may skip measurements based on one or more RSs of OD-RS(s) 2470. For example, a measurement of a CSI-RS configuration, where the CSI-RS is quasi-collocated with a SSB of OD-RS(s) 2470, WD 2410 may skip measurement on the CSI-RS configuration. WD 2410 may skip beam management, radio link monitoring, radio resource control measurement based on a RS of OD-RS(s) 2470 based on OD-RS(s) being deactivated.

[0546] In the specification, OD-RS may refer an on-demand SSB.

[0547] FIGS. 29A-29C show examples of the MAC CE, indicating activation or deactivation of OD-RSs (e.g , OD-SSBs) for serving cell(s) configured with multi-TRPs. Even though FIGS. 29A-29C shows that the MAC CE has one octet, a different number of octets, such as, for example, four, may be used for the MACDocket No.: 24-1240PCTCE. As shown in FIGS. 29A-29C, the MAC CE of a single octet may comprise seven C-fields and one R- field . The R-field may comprise a reserved bit. Each index of each of the seven C-fields is associated with a serving cell index (e.g., SCelllndex i). For example, the C-field C7 is associated with a serving cell having the serving cell index of 7.

[0548] In the MAC CE shown in FIG. 29A, each of the seven C-fields has a single bit indicating activation or activation of OD-RSs for all TRPs included in the corresponding serving cell. For example, if C7 in FIG. 29A has a bit value of 1 and the serving cell having the serving cell index of 7 includes two TPRs, the bit value of 1 in the C7 indicates that OD-RSs of both TRPs are activated. On the contrary, the bit value of 0 in the 07 indicates that OD-SSBs of both TRPs are deactivated.

[0549] In the MAC CE shown in FIG. 29B, each of the seven C-fields has multiple bits (e g., 2 bits) indicating activation or deactivation of OD-RSs for TPRs included in the corresponding serving cell. For example, if C7 in FIG. 29B comprises two bit values and the serving cell having the serving cell index of 7 includes two TPRs, one of the bit values indicates whether OD-RSs for one of the TRPs are activated or deactivated while another one of the bit values indicates whether OD-RSs for another one of the TRPs are activated or deactivated. More specifically, in one example, each digit in the two bit values may indicate activation or deactivation of OD-RSs for a certain TRP of the two TRPs. The paragraphs below provide an example of bit values and corresponding activation / deactivation states of OD-RSs for TRPs.

[0550] Bit Values: 00 - This may indicate that OD-RSs of both TRPs are deactivated.

[0551] Bit Values: 01 - This may indicate that OD-RSs for the TRP associated with the unit digit is activated while OD-RSs for the TRP associated with the tenth digit is deactivated.

[0552] Bit Values: 10 - This may indicate that OD-RSs for the TRP associated with the unit digit is deactivated while OD-RSs for the TRP associated with the tenth digit is activated.

[0553] Bit Values: 11 - This may indicate that OD-RSs of both TRPs are activated.

[0554] In the MAC CE shown in FIG. 29C, the MAC CE comprises two octets each of which is associated with a different one of two TPRs of the serving cell. Even though FIG. 29C only show two octets, the number of octets may be different depending on the number of TRPs of the serving cell. In FIG. 29C, each C-field indicates activation or deactivation of OD-RSs for the corresponding TRP of the serving cell. For example, in FIG. 29C, if the upper octet is associated with a first TRP of the serving cell and the lower octet is associated with a second TRP of the serving cell, the upper C7 having the value of 1 indicates activation of OD-RSs for the first TRP while the lower C7 having the value of 0 indicates deactivation of OD-SSBs for the second TRP.

[0555] As noted earlier, there is a possibility that RS(s) of TPR(s) in an mTRP scenario are deactivated, causing a problem. In order to avoid this problem, according to an aspect of an embodiment, the TAG(s) associated with the TRP(s) may be subject to one or more of the following requirements.Docket No.: 24-1240PCT

[0556] In one example, if CD-RS(s) are not present in the serving cell, a secondary TAG - i.e., the TAG in addition to the primary TAG - may not be configured. In other words, configuring the secondary TAG may require the presence of CD-RS(s) in the serving cell. In another example, configuring the secondary TAG may require the presence of CD-RS(s) in one or both of TRPs of the serving cell only if the serving cell is configured with OD-RS(s).

[0557] In a different example, if the serving cell is configured with semi-periodic RS(s) or periodic RS(s) with additional PCI, the second TAG may be configured.

[0558] Additional information about OD-SSB

[0559] OD-SSB may be defined or categorized as CD-SSB. In such case, CD-SSB that is not OD-SSB (a.k a., "non-OD-CD-SSB”) may be referred to as: i) periodic CD-SSB, ii) CD-SSB that is active while the reference cell is active, iii) CD-SSB indicated by system information block 1 (SIB1) or the IE called “servingcellconfigcommon”, and / or iv) non-on-demand CD-SSB

[0560] Alternatively, OD-SSB may be defined or categorized as NCD-SSB. In such case, NCD-SSB that is not OD-SSB (a.k.a., “non-OD-NCD-SSB") may be referred to as: i) periodic NCD-SSB, ii) NCD-SSB that is active while the reference cell is active, or iii) non-on-demand NCD-SSB.

[0561] UE's capability of supporting OD-SSB may require “ncd-SSB-BWPWor-r18.” Alternatively, UE's capability of supporting OD-SSB may be independent capability from NCD-SSB-BWPWor-r18. Such new capability may be referred to as “od-ncd-SSB-BWP-Wor.” This new capability may indicate whether the UE supports RLM / BM / BFD and (gapless) L3 intra-frequency measurements based on on-demand (or activable) NCD-SSB (i.e., OD-NCD-SSB) (within active BWP), when OD-NCD-SSB are activated or are active. Note that this feature applies only to SCell and it is not applicable to RedCap or eRedCap UEs.

[0562] OD-NCD-SSB are activated / deactivated by SSB activation / deactivation MAC CE and / or RRC configuration of the OD-NCD-SSB.

[0563] OD-NCD-SSB activation / deactivation may be applied to (option 1 : a firstActi veDownlinkBWP-ld) for the SCell or (an active BWP of the SCell)

[0564] bandwidth of the UE-specific RRC configured BWP may not comprise CD-SSB for Scell. OD-NCD- SSB (within the active DL BWP) may be used as the QCL source for other reference signal, when it’s activated. UE performs L3 intra-frequency measurements without gaps based on OD-NCD-SSB, where the OD-NCD-SSB is within the active DL BWP.

[0565] maxNumberODSSBAcrossCCs indicate the maximum number of od-NCD-SSBs configurations across CCs in a reported band (maxNumberODSSBAcrossCCs per band / band combination capability)

[0566] CD-SSBs or NCD-SSBs are not considered when couting the maximum number of OD-NCD-SSBs across CCs.Docket No.: 24-1240PCT

[0567] In an example, the existing definitions of CD-SSB and NCD-SSB may not change, and OD-SSB may be defined as an additional CD-SSB or an additional NCD-SSB. The additional CD-SSB or the additional NCD-SSB may be activated or deactivated by the MAC CE capable of indicating activation / deactivation of CD-SSB and / or NCD-SSB and / or RRC fongiratuion on the additional CD / NCD SSB.

[0568] In case additional CD-SSB, it may be called semi-persistent CD-SSB or on-demand CD-SSB.

[0569] Additional CD-SSB or additional NCD-SSB are present in a BWP indicated by firstActiveDownlinkBWP-ld of SCell. Additionally, it may be configured for other BWP(s) of the serving cell.

[0570] Note that a UE may not be required to or expected to measure OD-SSB for downlink timing of a TAG.

[0571] The paragraphs below disclose exemplary details of the embodiments disclosed above.

[0572] In an example, for serving cell(s) in sTAG, UE shall use any of the activated SCells with CD-SSB as the reference cell for deriving the UE transmit timing for the cells in the sTAG. UE initial transmit timing accuracy and gradual timing adjustment requirements are defined in the following requirements.

[0573] In an example, the term reference cell on a carrier frequency subject to CCA is not available at the UE refers to when at least one SSB is configured by gNB, but the first two successive candidate SSB positions for the same SSB index within the discovery burst transmission window are not available during at least one discovery burst transmission window, at the UE due to DL CCA failures at gNB during the last 1280 ms; otherwise the reference cell on the carrier frequency subject to CCA is considered as available at the UE.

[0574] In an example, the term reference cell on a carrier frequency subject to on-demand SSB is not available at the UE refers to when the on-demand SSB has been deactivated during the last 1280ms.

[0575] In an example, if the UE uses a reference cell on a carrier frequency subject to CCA or on-demand SSB for deriving the UE transmit timing, then the UE shall meet all the transmit timing requirements defined in clause 7.1.2 provided that the reference cell is available at the UE. If the reference cell is not available at the UE on a carrier frequency subject to CCA or on-demand SSB, then the UE is allowed to transmit in the uplink provided that the UE meets all the transmit timing requirements defined in clause 7.1 .2; otherwise the UE shall not transmit any uplink signal.

[0576] In an example, if a reference cell on a carrier frequency belonging to the PTAG, which is subject to CCA or on-demand SSB, is not available at the UE then the UE is allowed to use any of available activated SCell(s) at the UE in PTAG as a new reference cell.

[0577] In an example, if the SCell used as reference cell is deactivated, or becomes not available, the UE is allowed to use another active serving cell in PTAG as new reference cell.Docket No.: 24-1240PCT

[0578] In an example, if a reference cell on a carrier frequency belonging to the STAG, which is subject to CCA is not available at the UE, or if the SCell used as reference cell is deactivated, or becomes not available then the UE is allowed to use any of available activated SCell(s) at the UE in STAG as a new reference cell.

[0579] In an example, for serving cell(s) in sTAG, UE shall use any of the activated SCells with semiperiodic or periodic SSBs as the reference cell for deriving the UE transmit timing for the cells in the sTAG. UE initial transmit timing accuracy and gradual timing adjustment requirements are defined in the following requirements.

[0580] In an example, the UE shall have capability to follow the frame timing change of the reference cell in connected state or when transmiting PUSCH on CG resources for SDT in RRCJnactive. The uplink frame transmission takes place ( N TA + N TA offset ) A~ T c before the reception of the first detected path (in time) of the corresponding downlink frame from the reference cell. For serving cell(s) in pTAG, UE shall use the SpCell as the reference cell for deriving the UE transmit timing for cells in the pTAG. For serving cell(s) in sTAG, UE shall select an active SCell, with CD-SSBs, of the activated SCells if any. Otherwise, UE shall use any of the activated SCells as the reference cell for deriving the UE transmit timing for the cells in the sTAG.

[0581] In an example, in case timeAlignmentTimer is expired: When the MAC entity stops uplink transmissions associated to a STAG for an SCell configured with two TAGs due to the fact that the maximum uplink transmission timing difference between TAGs of the MAC entity or the maximum uplink transmission timing difference between TAGs of any MAC entity of the UE is exceeded or on-demand SSBs are deactivated in both coreset pools, the MAC entity considers the timeAlignmentTimer associated with the STAG as expired.

[0582] In an example, for activation / deactivation of on-demand SSBs: The network may activate and deactivate the on-demand SSBs for a Serving Cell or a set of Serving Cells or one or more coreset pools of a Serving Cell / a set of Serving cells by sending the OD-SSB Acti vation / Deacti vation MAC CE.

[0583] In an example, the MAC entity shall:

[0584] 1> if the MAC CE entity indicates deactivation an OD-SSBs on a Serving Cell:

[0585] 2> If the Serving Cell is configured with two TAGs and SSB-MTC-AdditionalPCI / / inter-cell mTRP case

[0586] 3> if the MAC CE entity indicates deactivation on a PCI in SSB-MTC-AdditionalPCI, consider timeAlignmentTimer of tag-ld2 of the Serving cell expired

[0587] 3> if the MAC CE entity indicates deactivation on a PCI of the Servnig Cell, consider timeAlignmentTimer of tag-id of the Serving cell expired

[0588] 1> if the MAC CE entity indicates activation an OD-SSBs on a Serving Cell:Docket No.: 24-1240PCT

[0589] 2> If the Serving Cell is configured with two TAGs and SSB-MTC-AdditionalPCI / / inter-cell mTRP case

[0590] 3> if the MAC CE entity indicates deactivation on a PCI in SSB-MTC-AdditionalPCI, consider timeAlignmentTimer of tag-ld2 of the Serving c...

Claims

Docket No.: 24-1240PCTCLAIMS1. A method comprising: receiving, by a wireless device, one or more messages indicating a timing advance group (TAG) which comprises a first secondary cell (SCell) and a second SCell; and transmitting, via the first SCell and / or the second SCell, one or more uplink transmissions, using a transmit timing which is based on a reference cell for the TAG, wherein one of the first SCell and the second SCell is selected as the reference cell based on whether the first SCell is configured with one or more on-demand synchronization signal blocks (SSBs).

2. A method comprising: transmitting, by a wireless device, one or more uplink transmissions, using a transmit timing which is based on a reference cell, wherein the reference cell is selected based on whether a first cell is configured with one or more on-demand synchronization signal blocks (SSBs).

3. The method of claim 2, wherein: the reference cell is for a timing advance group (TAG); and the TAG comprises the first cell and a second cell.

4. The method of claim 3, wherein the one or more uplink transmissions are transmitted via the first cell and / or the second cell.

5. The method of claim 3 or 4, comprising receiving, by the wireless device, one or more messages indicating the TAG.

6. The method of any one of claims 3-5, wherein: the first cell is a first secondary cell (SCell); and the second cell is a second SCell.

7. The method of any one of claims 3-6, wherein one of the first cell and the second cell is selected as the reference cell based on whether the first cell is configured with one or more on-demand SSBs8. The method of any one of claims 3-7, further comprising: receiving one or more first messages indicating and on-demand SSB of the first cell, wherein the on- demand SSB is configured to be activated or deactivated; determining that the first SCell is not configured with periodic SSB; and based on the determination, selecting, as the reference cell for determining a downlink timing of the TAG, the second SCell that is different from the first SCell.

9. The method of claim 8, wherein the first SCell is determined as not being configured with periodic SSB, based on: the first SCell not transmitting any cell defining SSB; and the first SCell not transmitting any non-cell defining SSB.Docket No.: 24-1240PCT10. The method of claim 8 or 9, further comprising: determining that the second SCell is configured with i) one or more cell defining SSBs or one or more non-cell defining SSBs and ii) one or more on-demand SSBs; and measuring the downlink timing of the TAG based on measuring: the one or more on-demand SSBs of the second SCell in response to: transmission of the one or more on-demand SSBs of the second SCell being activated; and the one or more on-demand SSBs of the second SCell being comprised in an active bandwidth part of the second SCell; and / or the one or more cell defining SSBs or the one or more non-cell defining SSBs of the second SCell in response to: the one or more on-demand SSBs of the second SCell being not activated; or the one or more on-demand SSBs of the second SCell being not comprised in the active bandwidth part of the second SCell, wherein the second SCell is the reference cell of the TAG.11 . The method of any one of claims 8-10, further comprising determining the transmit timing of the TAG as the downlink timing minus a timing advance (TA) value, wherein the TA value is derived based on a sum of a TA offset and a TA.

12. The method of claim 11 , wherein the one or more messages comprise the TA offset.

13. The method of claim 11 or 12, further comprising receiving one or more medium access control (MAC) control elements (CEs) comprising one or more timing advance commands.

14. The method of claim 13, further comprising updating the TA based on the one or more timing advance commands.

15. The method of any one of claims 11-14, further comprising: determining a second transmit timing of the TAG as the downlink timing minus the timing advance offset; and transmitting an uplink signal, via a cell of the TAG, using the second transmit timing.

16. The method of claim 15, wherein the uplink signal is a preamble transmitted via a physical random access channel (PRACH).

17. The method of any one of claims 2-16, wherein the one or more uplink transmissions comprise one or more transmissions of one or more of: physical uplink shared channel (PUSCH), physical uplink control channel (PUCCH), and sounding reference signal (SRS).

18. The method of any one of claims 5-17, wherein the one or more messages are radio resource control (RRC) messages.Docket No.: 24-1240PCT19. The method of any one of claims 3-18, wherein the TAG is a secondary TAG of the wireless device.

20. The method of any one of claims 3-19, wherein the TAG does not comprise a primary cell of the wireless device.21 . The method any one of claims 2-20, further comprising receiving one or more downlink control commands indicating activation of the transmission of one or more on-demand SSBs of the second cell, wherein the one or more downlink control command comprises one or more of: one or more RRC messages, one or more MAC CEs, and one or more downlink control information (DCI).

22. The method of claim 6 or 7, further comprising: receiving one or more first messages indicating one or more on-demand SSBs of the first SCell; and selecting the first SCell as the reference cell for measuring a downlink timing of the TAG, wherein: transmission of the one or more on-demand SSBs of the first SCell is activated; and the transmit timing is determined based on the downlink timing of the TAG.

23. The method of claim 22, further comprising measuring the one or more on-demand SSBs of the first SCell for the determining the downlink timing of the TAG.

24. The method of claim 22 or 23, further comprising: after the first SCell is selected as the reference cell, determining that the one or more on-demand SSBs of the first SCell are deactivated; based on the determination, selecting, as an updated reference cell for measuring the downlink timing of the TAG, the second SCell that is different from the first SCell; and determining an updated transmit timing based on selecting the second SCell as the updated reference cell.

25. The method of any one of claims 22-24, further comprising: receiving one or more second messages indicating that the one or more on-demand SSBs of the first SCell are deactivated, wherein the one or more on-demand SSBs of the first SCell are determined as deactivated based on the indication.

26. The method of claim 25, wherein: the one or more second messages include one or more of: a medium access control (MAC) control element (CE), a radio source control (RRC) message, or downlink control information (DCI), and the one or more of the MAC CE, the RRC message, or the DCI indicate that the one or more on- demand SSBs of the first SCell are deactivated.

27. The method of any one of claims 22-24, further comprising: starting a timer; andDocket No.: 24-1240PCT based on failing to receive OD-SSBs of the first SCell within a certain duration after the timer is started, determining that OD-SSBs of the first SCell are deactivated.

28. The method of any one of claims 22-27, further comprising determining that the first SCell is unavailable based on determining that the one or more on-demand SSBs of the first SCell are deactivated for a certain duration, wherein the second SCell is selected as the updated reference cell based on determining that the first SCell is unavailable.

29. The method of claim 28, further comprising determining that the first SCell is unavailable based on determining that the one or more on-demand SSBs of the first SCell are deactivated, wherein the second SCell is selected as the updated reference cell based on determining that the first SCell is unavailable.

30. The method of any one of claims 25-27, further comprising determining that the first SCell is unavailable based on receiving the one or more second messages indicating that the one or more on- demand SSBs of the first SCell being deactivated.31 . The claims of any one of claims 28-30, wherein the wireless device is allowed to select the second SCell as the updated reference cell based on determining that the first SCell is unavailable.

32. The claims of any one of claims 24-31 , further comprising determining the transmit timing and the downlink timing of the TAG based on the updated reference cell.

33. The method of any one of claims 24-32, further comprising: receiving one or more messages indicating the TAG which comprises a set of cells, wherein after determining that the one or more on-demand SSBs of the first SCell are deactivated, the second SCell is selected, from a first subset of one or more cells included in the set, as the updated reference cell, and the first subset of one or more cells does not include the first SCell.

34. A method comprising: receiving, by a wireless device, one or more configuration parameters indicating a configuration for a serving cell, wherein the configuration indicates: a first control resource set (CORESET) pool index associated with a first timing advance group (TAG); and a second CORESET pool index associated with a second TAG; receiving one or more messages indicating activation or deactivation of one or more on-demand synchronization signals (OD-SSs) associated with the second CORESET pool index of the serving cell; and transmitting one or more uplink transmissions using the first TAG and / or the second TAG, based on the indication.Docket No.: 24-1240PCT35. A method comprising: transmitting, by a wireless device, one or more uplink transmissions using a first timing advance group (TAG) and / or a second TAG, based on whether one or more on-demand synchronization signals (OD-SSs) associated with the second TAG is activated or deactivated.

36. The method of claim 35, comprising receiving one or more messages indicating activation or deactivation of the one or more OD-SSs associated with the second TAG, wherein the one or more uplink transmissions are transmitted using the first TAG and / or the second TAG, based on the indication.

37. The method of claim 35 or 36, comprising receiving, by the wireless device, one or more configuration parameters indicating a configuration for a serving cell, wherein the configuration indicates: a first control resource set (CORESET) pool index associated with the first TAG; and a second CORESET pool index associated with the second TAG;38. The method of claim 37, wherein the one or more OD-SSs are associated with the second TAG.

39. The method of any one of claims 35-38, wherein the one or more configuration parameters further indicate: the one or more OD-SSs for the second TAG; and one or more second OD-SSs for the first TAG.

40. The method of claim 39, wherein the one or more OD-SSs is for the second TAG based on a transmission configuration indicator (TCI) state of the second TAG indicating an OD-SS of the one or more OD-SSs.41 . The method of claim 39 or 40, wherein the one or more second OD-SSs is for the first TAG based on a TCI state of the first TAG indicates an OD-SS of the one or more second OD-SSs.

42. The method of any one of claims 38-41 , wherein the one or more second OD-SSs are associated with the first TAG based on a physical cell identifier of the one or more second OD-SSs being same as a physical cell identifier of the serving cell.

43. The method of any one of claims 38-42, wherein the one or more OD-SSs are associated with the second TAG based on a physical cell identifier of the one or more OD-SSs being different from the physical cell identifier of the serving cell.

44. The method of any one of claims 37-43, wherein: the first CORESET pool index is associated with the first TAG based on a TCI state of the first CORESET pool index being indicated / configured with a tag identifier of the first TAG; and / or the second CORESET pool index is associated with the second TAG based on a TCI state of the second CORESET pool index being indicated / configured with a tag identifier of the second TAG.Docket No.: 24-1240PCT45. The method of any one of claims 37-44, wherein the one or more messages comprise one or more medium access control (MAC) control elements (CEs) indicating activation or deactivation of the one or more OD-RSs associated with the second CORESET pool index.

46. The method of claim 45, wherein: the one or more MAC CEs comprise a plurality of fields each of which is associated with a particular serving cell ; and the plurality of fields includes a first field associated with the serving cell.

47. The method of claim 46, wherein the first field comprises a single bit value indicating whether OD-SSs associated with both the first and second CORESET pool indexes are activated or deactivated.

48. The method of claim 46, wherein: the first field comprises: at least a first bit value associated with the first CORESET pool index; and a second bit value associated with the second CORESET pool index; the first bit value indicates whether one or more OD-RSs associated with the first CORESET pool index are activated or deactivated; and the second bit value indicates whether one or more OD-RSs associated with the second CORESET pool index are activated or deactivated.

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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