Application of timing advance command for access channel message to timing advance group of plurality of timing advance groups

Abstract

Aspects of the present disclosure generally relate to wireless communications. In some aspects, a UE may receive an indication of a first TAG associated with a first wireless link of a serving cell and a second TAG associated with a second wireless link of the serving cell. The UE may transmit a first RACH message based at least in part on a failure of a BFR procedure associated with at least one of a first set of BFD-RSs associated with the first radio link or a second set of BFD-RSs associated with the second radio link. The UE may receive a second RACH message indicating a TAC for the serving cell based at least in part on transmitting the first RACH message. The UE may communicate with the serving cell based at least in part on application of the TAC to the first TAG or the second TAG.

Description

Technical Field

[0001] Aspects of the present disclosure relate generally to wireless communications, and more particularly to techniques and apparatus for applying a timing advance command of an access channel message to a timing advance group (TAG) among a plurality of TAGs. Background Art

[0002] Wireless communication systems are widely deployed to provide a variety of telecommunication services, such as telephony, video, data, messaging, and broadcasting. Typical wireless communication systems may employ multiple access technologies that can support communication with multiple users by sharing available system resources (e.g., bandwidth or transmit power). Examples of such multiple access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single carrier frequency division multiple access (SC-FDMA) systems, time division synchronous code division multiple access (TD-SCDMA) systems, and long term evolution (LTE). LTE / LTE-Advanced is a set of enhancements to the Universal Mobile Telecommunications System (UMTS) mobile standard promulgated by the Third Generation Partnership Project (3GPP).

[0003] The above multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different UEs to communicate at a city, country, region or global level. New Radio (NR) (which may be referred to as 5G) is an enhancement set to the LTE mobile standard promulgated by 3GPP. NR is designed to better support mobile broadband Internet access by: improving frequency efficiency; reducing costs; improving services; utilizing new spectrum; and using orthogonal frequency division multiplexing (OFDM) (CP-OFDM) with cyclic prefix (CP) on the downlink, CP-OFDM or single carrier frequency division multiplexing (SC-FDM) (also known as discrete Fourier transform spread OFDM (DFT-s-OFDM) on the uplink to better integrate with other open standards; and supporting beamforming, multiple input and output (MIMO) antenna technology and carrier aggregation. As the demand for mobile broadband access continues to increase, further improvements in LTE, NR and other radio access technologies remain useful.

[0004] In some networks, a UE may communicate with a network node via multiple transmit receive points (TRPs). For example, a UE may communicate with a network node via a first radio link having a first TRP and a second radio link having a second TRP. The first TRP may be associated with a first timing advance group (TAG), and the second TRP may be associated with a second TAG (e.g., at least in part based on the first TRP and the first TAG being associated with a first control resource set (CORESET) pool index, and the second TRP and the second TAG being associated with a second CORESET pool index). The timing advance (TA) of the TAG may be a candidate for selection for use in communications between the UE and the network node. For example, the TA of the first TAG may indicate the amount of time to change the uplink communication (e.g., change earlier) relative to a timing event associated with the downlink communication. In the case of selecting the TA, the UE may use the TA to send uplink communications. In this way, the UE may change the timing of the communication to take into account the propagation delay of the signal traveling between the UE and the network node.

[0005] The UE may identify a beam failure for one or more of the first radio link or the second radio link (e.g., based on identifying a beam failure detection (BFD) event). Based at least in part on the beam failure, the UE may trigger a per-TRP beam failure recovery (BFR) procedure to reestablish the first radio link or the second radio link. If the BFR procedure fails, the UE may initiate a random access procedure.

[0006] In an example where a per-TRP BFR procedure is employed, a corresponding BFD reference signal (RS) set, a corresponding new beam identifier RS ​​(NBI-RS) set, and a corresponding BFD count and a corresponding timer are associated with corresponding TRPs in the first TRP and the second TRP. In an example where a serving cell (e.g., a special cell (SpCell)) is configured with two BFD-RS sets and in the event that all BFD-RS sets fail in the serving cell, the UE may trigger a contention-based random access (CBRA) procedure. In addition, the UE may trigger a CBRA in the event that at least one of the BFD-RS sets fails, a physical uplink control channel (PUCCH) scheduling request (SR) is not configured, and no uplink grant is available. During a random access procedure associated with CBRA, the network node may send an indication of a timing advance command (TAC) to indicate the TA to be used during or after the random access procedure. Summary of the invention

[0007] Some aspects described herein relate to a method of wireless communication performed by a user equipment (UE). The method may include receiving an indication of a first timing advance group (TAG) associated with a first radio link of a serving cell and a second TAG associated with a second radio link of the serving cell. The method may include sending a first random access channel (RACH) message on a serving cell based at least in part on a failure of a beam failure recovery (BFR) process associated with at least one of a first beam failure detection (BFD) reference signal (RS) set associated with the first radio link or a second BFD-RS set associated with the second radio link. The method may include receiving a second RACH message indicating a timing advance command (TAC) for a serving cell based at least in part on sending the first RACH message. The method may include communicating with a serving cell based at least in part on the application of a TAC to a first TAG or a second TAG, the application of the TAC to the first TAG or the second TAG being based at least in part on one or more of: whether a new candidate beam associated with the first radio link or the second radio link is identified prior to sending a first RACH message; a BFD-RS set in the first BFD-RS set or the second BFD-RS set that is not the at least one BFD-RS set for which a BFR process is not triggered; or a synchronization signal block (SSB) associated with the first RACH message.

[0008] Some aspects described herein relate to a UE for wireless communication. The user equipment may include at least one processor and at least one memory storing a processor-readable code, the at least one memory being communicatively coupled to the at least one processor. The processor-readable code, when executed by the at least one processor, may be configured to cause the user equipment to receive an indication of a first TAG associated with a first radio link of a serving cell and a second TAG associated with a second radio link of the serving cell. The processor-readable code, when executed by the at least one processor, may be configured to cause the user equipment to send a first RACH message on the serving cell based at least in part on a failure of a BFR process associated with at least one BFD-RS set from a first BFD-RS set associated with a first radio link or a second BFD-RS set associated with a second radio link. The processor-readable code, when executed by the at least one processor, may be configured to cause the user equipment to receive a second RACH message indicating a TAC for a serving cell based at least in part on sending a first RACH message. The processor-readable code, when executed by the at least one processor, may be configured to cause the user equipment to communicate with the serving cell based at least in part on the application of the TAC to the first TAG or the second TAG, the application of the TAC to the first TAG or the second TAG being based at least in part on one or more of: whether a new candidate beam associated with the first wireless link or the second wireless link is identified prior to the transmission of the first RACH message; a BFD-RS set in the first BFD-RS set or the second BFD-RS set that is not the at least one BFD-RS set for which the BFR process is not triggered; or an SSB associated with the first RACH message.

[0009] Some aspects described herein relate to a non-transitory computer-readable medium storing an instruction set for wireless communication by a UE. The instruction set, when executed by one or more processors of the UE, may cause the UE to receive an indication of a first TAG associated with a first radio link of a serving cell and a second TAG associated with a second radio link of the serving cell. The instruction set, when executed by one or more processors of the UE, may cause the UE to send a first RACH message on the serving cell based at least in part on a failure of a BFR process associated with at least one of a first BFD-RS set associated with the first radio link or a second BFD-RS set associated with the second radio link. The instruction set, when executed by one or more processors of the UE, may cause the UE to receive a second RACH message indicating a TAC for the serving cell based at least in part on sending the first RACH message. The instruction set, when executed by one or more processors of the UE, may cause the UE to communicate with a serving cell based at least in part on the application of the TAC to the first TAG or the second TAG, the application of the TAC to the first TAG or the second TAG being based at least in part on one or more of: whether a new candidate beam associated with the first radio link or the second radio link is identified prior to the transmission of the first RACH message; a BFD-RS set in the first BFD-RS set or the second BFD-RS set that is not the at least one BFD-RS set for which the BFR process is not triggered; or an SSB associated with the first RACH message.

[0010] Some aspects described herein relate to an apparatus for wireless communication. The apparatus may include components for receiving an indication of a first TAG associated with a first radio link of a serving cell and a second TAG associated with a second radio link of the serving cell. The apparatus may include components for sending a first RACH message on a serving cell based at least in part on a failure of a BFR process associated with at least one of a first BFD-RS set associated with the first radio link or a second BFD-RS set associated with the second radio link. The apparatus may include components for receiving a second RACH message indicating a TAC for a serving cell based at least in part on sending the first RACH message. The apparatus may include means for communicating with a serving cell based at least in part on application of a TAC to a first TAG or a second TAG, the application of the TAC to the first TAG or the second TAG being based at least in part on one or more of: whether a new candidate beam associated with the first radio link or the second radio link is identified prior to transmission of a first RACH message; a BFD-RS set in the first BFD-RS set or the second BFD-RS set that is not the at least one BFD-RS set for which a BFR process is not triggered; or an SSB associated with the first RACH message.

[0011] Aspects collectively include methods, apparatus, systems, computer program products, non-transitory computer-readable media, user equipment, base stations, network nodes, network entities, wireless communication devices, or processing systems as fully described with reference to the accompanying drawings and the specification and as illustrated in the accompanying drawings and the specification.

[0012] The foregoing has broadly outlined the features and technical advantages of examples according to the present disclosure in an effort to make the following specific embodiments better understood. Additional features and advantages will be described below. The disclosed concepts and specific examples can be easily used as a basis for modifying or designing other structures for the same purpose of achieving the present disclosure. Such equivalent constructions do not depart from the scope of the appended claims. When considered in conjunction with the accompanying drawings, the characteristics of the concepts disclosed herein (both their organization and method of operation) and the associated advantages will be better understood according to the following description. Each of the figures in the accompanying drawings is provided for the purpose of illustration and description, and not as a definition of limitations to the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to fully understand the above features of the present disclosure, a more specific description of the invention briefly summarized above can be obtained by referring to various aspects (some of which are illustrated in the accompanying drawings). However, it should be noted that the accompanying drawings only illustrate some typical aspects of the present disclosure and should not be considered to limit its scope, as the description may allow for other equally effective aspects. The same reference numerals in different drawings may identify the same or similar elements.

[0014] Figure 1 is a diagram illustrating an example of a wireless network according to the present disclosure.

[0015] Figure 2 is a diagram illustrating an example network node communicating with a user equipment (UE) in a wireless network according to the present disclosure.

[0016] Figure 3 is a diagram illustrating an example decomposed base station architecture according to the present disclosure.

[0017] Figure 4 is a diagram illustrating an example of a beam failure recovery process according to the present disclosure.

[0018] Figure 5 is a diagram illustrating an example of a four-step random access procedure according to the present disclosure.

[0019] Figure 6 is a diagram of an example associated with applying a timing advance command (TAC) of an access channel message to a TAG among a plurality of timing advance groups (TAGs) according to the present disclosure.

[0020] Figure 7 is a diagram illustrating an example of a four-step random access procedure according to the present disclosure.

[0021] Figure 8 is a diagram illustrating an example of a four-step random access procedure according to the present disclosure.

[0022] Fig. 9 is a diagram illustrating an example of a four-step random access procedure according to the present disclosure.

[0023] Fig.10 is a diagram illustrating an example of a four-step random access procedure according to the present disclosure.

[0024] Fig.11 is a diagram illustrating an example of a four-step random access procedure according to the present disclosure.

[0025] Fig.12 is a flow chart illustrating an example process performed, for example, by a UE supporting selection of a TAG in a multi-TAG communication scheme according to the present disclosure, to which the UE applies a TAC received during a random access procedure.

[0026] Fig.13 is a diagram of an example apparatus for wireless communications according to the present disclosure. DETAILED DESCRIPTION

[0027] The various aspects of the present disclosure are described more fully below with reference to the accompanying drawings. However, the present disclosure can be embodied in many different forms, and should not be interpreted as being limited to any specific structure or function given throughout the present disclosure. On the contrary, these aspects are provided so that the present disclosure will be thorough and complete, and the scope of the present disclosure will be fully conveyed to those skilled in the art. It will be appreciated by those skilled in the art that the scope of the present disclosure is intended to cover any aspect of the present disclosure disclosed herein, whether it is implemented independently or in combination with any other aspect of the present disclosure. For example, the aspect of any amount set forth herein may be used to implement a device or practice method. In addition, the scope of the present disclosure is intended to cover such a device or method that is practiced using other structures, functions, or structures and functions in addition to or different from the various aspects of the disclosure set forth herein. Any aspect of the present disclosure disclosed herein may be embodied by one or more elements of a claim.

[0028] Several aspects of telecommunication systems will now be presented with reference to various devices and techniques. These devices and techniques will be described in the following detailed description and illustrated in the accompanying drawings by various blocks, modules, components, circuits, steps, processes, or algorithms (collectively referred to as "elements"). These elements can be implemented using hardware, software, or a combination of hardware and software. Whether these elements are implemented as hardware or software depends on the specific application and the design constraints imposed on the overall system.

[0029] Various aspects generally relate to applying a timing advance command (TAC) indicated during a random access procedure to a first timing advance group (TAG) or a second TAG. Some aspects more specifically relate to communicating based at least in part on the application of the TAC to the first TAG or the second TAG in a multiple transmit receive point (TRP) scenario. In some aspects, a user equipment (UE) may initiate a random access procedure after a beam failure recovery (BFR) procedure fails.

[0030] In some examples, the UE may apply the TAC to the first TAG based at least in part on a failure to identify any new candidate beams for any new beam identification (NBI) reference signal (RS) set when sending the first random access message. For example, the UE may apply the TAC to the first TAG based at least in part on the first TAG being associated with a first TAG associated with a first TAG index, a lowest TAG identity relative to a second TAG identity associated with a second TAG, or being associated with a default control resource set (CORESET) pool index, etc.

[0031] In some other examples, the UE may apply the TAC to the first TAG based at least in part on identifying a new candidate beam in the NBI-RS set when sending the first random access message. For example, the UE may apply the TAC to the first TAG based at least in part on the first TAG being associated with the NBI-RS set in which the UE identifies the new candidate beam.

[0032] In some other examples, the UE may apply the TAC to the first TAG based at least in part on the UE selecting a synchronization signal block (SSB) from an NBI-RS set associated with the first TAG.

[0033] In some aspects, when sending the first random access message, the UE may identify a first new candidate beam in a first NBI-RS set associated with a first TAG and a second new candidate beam in a second NBI-RS set associated with a second TAG. For example, the UE may apply the TAC to the first TAG based at least in part on the first TAG being associated with an NBI-RS set to which the selected SSB belongs. The SSB may belong to an NBI-RS set based at least in part on being received on a beam within the NBI-RS set.

[0034] In some other examples, the UE may apply the TAC to the first TAG based at least in part on not triggering the BFR procedure for the BFD-RS set associated with the first TAG. For example, the UE may apply the TAC to the first TAG based at least in part on triggering the BFR procedure for the BFD-RS set associated with the second TAG.

[0035] In some other examples, the UE may apply the TAC to the first TAG based at least in part on the same CORESET pool index being associated with the first TAG and the SSB associated with the first random access message or the first TAG being associated with the SSB associated with the first random access message.

[0036] Certain aspects of the subject matter described in the present disclosure may be implemented to achieve one or more of the following potential advantages. In some examples, the described techniques may be used to synchronize the application of a TAC to one of a plurality of TAGs between a UE and a network node, where the TAGs are associated with different TRPs or radio links of a serving cell. In this way, the UE may apply the TAC to an expected TAG (e.g., expected by a network node) for configuring the timing of communications using the expected TAG and associated communication links or beams. Based at least in part on applying the TAC to the expected TAG, the UE and the network node may have improved timing synchronization, reduced error rates, and improved spectral efficiency. In this way, the UE and the network node may save power, computing, network, and communication resources that would otherwise be used to detect and correct errors associated with applying the TAC to an unexpected TAG.

[0037] Figure 1 1 is a diagram illustrating an example of a wireless network according to the present disclosure. The wireless network 100 may be a 5G (e.g., NR) network or a 4G (e.g., Long Term Evolution (LTE)) network, or may include elements of a 5G (e.g., NR) network or elements of a 4G (e.g., Long Term Evolution (LTE)) network, as well as other examples. The wireless network 100 may include one or more network nodes 110 (shown as network node (NN) 110a, network node 110b, network node 110c, and network node 110d), one UE 120 or multiple UEs 120 (shown as UE 120a, UE 120b, UE 120c, UE 120d, and UE 120e), and / or other network entities. The network node 110 is an entity that communicates with the UE 120. As shown in the figure, the network node 110 may include one or more network nodes. For example, the network node 110 may be a converged network node, which means that the converged network node is configured to utilize a radio protocol stack that is physically or logically integrated within a single RAN node (e.g., within a single device or unit). For another example, the network node 110 may be a decomposed network node (sometimes referred to as a decomposed base station), which means that the network node 110 is configured to utilize a protocol stack that is physically or logically distributed between two or more nodes (such as one or more central units (CUs), one or more distributed units (DUs), or one or more radio units (RUs)).

[0038] In some examples, the network node 110 is or includes a network node that communicates with the UE 120 via a radio access link, such as an RU. In some examples, the network node 110 is or includes a network node that communicates with other network nodes 110 via a fronthaul link or a midhaul link, such as a DU. In some examples, the network node 110 is or includes a network node that communicates with other network nodes 110 via a midhaul link or communicates with a core network via a backhaul link, such as a CU. In some examples, the network node 110 (such as an aggregated network node 110 or a decomposed network node 110) may include multiple network nodes, such as one or more RUs, one or more CUs, or one or more DUs. The network node 110 may include, for example, an NR network node, an LTE network node, a Node B, an eNB (e.g., in 4G), a gNB (e.g., in 5G), an access point, a transmit receive point (TRP), a DU, a RU, a CU, a mobility element of a network, a core network node, a network element, a network equipment, or a RAN node. In some examples, network nodes 110 may be interconnected to each other or to one or more other network nodes 110 in wireless network 100 via various types of fronthaul interfaces, midhaul interfaces, or backhaul interfaces (such as direct physical connections, air interfaces, or virtual networks) using any suitable transport network.

[0039] Each network node 110 may provide communication coverage for a particular geographic area. In the 3rd Generation Partnership Project (3GPP), the term "cell" may refer to a coverage area of ​​a network node 110 or a network node subsystem serving the coverage area, depending on the context in which the term is used.

[0040] The network node 110 may provide communication coverage for a macro cell, a pico cell, a femto cell, or another type of cell. A macro cell may cover a relatively large geographic area (e.g., a radius of several thousand meters) and may allow unrestricted access by a UE 120 with a service subscription. A pico cell may cover a relatively small geographic area and may allow unrestricted access by a UE 120 with a service subscription. A femto cell may cover a relatively small geographic area (e.g., a residence) and may allow restricted access by a UE 120 associated with the femto cell (e.g., a UE 120 in a closed subscriber group (CSG)). A network node 110 for a macro cell may be referred to as a macro network node. A network node 110 for a pico cell may be referred to as a pico network node. A network node 110 for a femto cell may be referred to as a femto network node or a home network node.

[0041] The wireless network 100 may be a heterogeneous network that includes different types of network nodes 110, such as macro network nodes, pico network nodes, femto network nodes, or relay network nodes. These different types of network nodes 110 may have different transmit power levels, different coverage areas, or different effects on interference in the wireless network 100. For example, a macro network node may have a high transmit power level (e.g., 5 watts to 40 watts), while a pico network node, a femto network node, and a relay network node may have a lower transmit power level (e.g., 0.1 watt to 2 watts). Figure 1 In the example shown in , network node 110a may be a macro network node for macro cell 102a, network node 110b may be a pico network node for pico cell 102b, and network node 110c may be a femto network node for femto cell 102c. A network node may support one or more (e.g., three) cells. In some examples, a cell may not necessarily be stationary, and the geographic area of ​​a cell may move depending on the location of a mobile network node 110 (e.g., a mobile network node).

[0042] In some aspects, the term "base station" or "network node" may refer to an aggregated base station, a decomposed base station, an integrated access and backhaul (IAB) node, a relay node, or one or more components thereof. For example, in some aspects, a "base station" or "network node" may refer to a CU, a DU, a RU, a near real-time (near RT) RAN intelligent controller (RIC), or a non-real-time (non-RT) RIC. In some aspects, the term "base station" or "network node" may refer to a device configured to perform one or more functions (such as those described herein in conjunction with network node 110). In some aspects, the term "base station" or "network node" may refer to multiple devices configured to perform one or more functions. For example, in some distributed systems, each of a number of different devices (which may be located in the same geographic location or in different geographic locations) may be configured to perform at least a portion of a function, or to repeat the execution of at least a portion of the function, and the term "base station" or "network node" may refer to any one or more of these different devices. In some aspects, the term "base station" or "network node" may refer to one or more virtual base stations or one or more virtual base station functions. For example, in some aspects, two or more base station functions may be instantiated on a single device. In some aspects, the term "base station" or "network node" may refer to one of the base station functions but not the other. In this way, a single device may include more than one base station.

[0043] The network controller 130 may be coupled to or in communication with a set of network nodes 110 and may provide coordination and control for the network nodes 110. The network controller 130 may communicate with the network nodes 110 via a backhaul communication link. The network nodes 110 may also communicate directly with each other or indirectly via a wireless backhaul communication link or a wired backhaul communication link. In some aspects, the network controller 130 may be a CU or a core network device, or the network controller 130 may include a CU or a core network device.

[0044] In some examples, the cells may not necessarily be stationary, and the geographic area of ​​the cells may move depending on the location of the mobile network nodes 110 (e.g., mobile network nodes). In some examples, the network nodes 110 may be interconnected with each other or to one or more other network nodes 110 or network nodes (not shown) in the wireless network 100 using any suitable transport network through various types of backhaul interfaces (such as direct physical connections or virtual networks).

[0045] The wireless network 100 may include one or more relay stations. A relay station is an entity that can receive data transmissions from an upstream station (e.g., a network node 110 or a UE 120) and transmit the data transmissions to a downstream station (e.g., a UE 120 or a network node 110). A relay station may be a UE 120 that is capable of relaying transmissions for other UEs 120. Figure 1 In the example shown in , a network node 110d (e.g., a relay network node) may communicate with a network node 110a (e.g., a macro network node) and a UE 120d to facilitate communications between the network node 110a and the UE 120d. A network node 110 that relays communications may be referred to as a relay station, a relay network node, or a relay.

[0046] UE 120 can be distributed throughout the wireless network 100, and each UE 120 can be stationary or mobile. UE 120 can include, for example, an access terminal, a terminal, a mobile station, or a subscriber unit. UE 120 can be a cellular phone (e.g., a smart phone), a personal digital assistant (PDA), a wireless modem, a wireless communication device, a handheld device, a laptop computer, a cordless phone, a wireless local loop (WLL) station, a tablet device, a camera, a gaming device, a netbook, a smartbook, an ultrabook, a medical device, a biometric device, a wearable device (e.g., a smart watch, smart clothing, smart glasses, a smart wristband, smart jewelry (e.g., a smart ring or a smart bracelet)), an entertainment device (e.g., a music device, a video device, or a satellite radio), a vehicle component or sensor, a smart meter / sensor, an industrial manufacturing equipment, a global positioning system device, a UE function of a network node, or any other suitable device configured to communicate via a wireless medium.

[0047] Some UEs 120 may be considered as machine type communication (MTC) or evolved or enhanced machine type communication (eMTC) UEs. MTC UEs or eMTC UEs may include, for example, robots, drones, remote devices, sensors, meters, monitors, or location tags, which may communicate with a network node, another device (e.g., a remote device), or some other entity. Some UEs 120 may be considered as Internet of Things (IoT) devices, or may be implemented as NB-IoT (narrowband IoT) devices. Some UEs 120 may be considered as customer premises equipment. UE 120 may be included inside a housing that houses components of UE 120, such as a processor component or a memory component. In some examples, the processor component and the memory component may be coupled together. For example, a processor component (e.g., one or more processors) and a memory component (e.g., a memory) may be operably coupled, communicatively coupled, electronically coupled, or electrically coupled.

[0048] In general, any number of wireless networks 100 may be deployed in a given geographic area. Each wireless network 100 may support a specific RAT and may operate on one or more frequencies. RAT may also be referred to as a radio technology or air interface. Frequency may also be referred to as a carrier or frequency channel. Each frequency may support a single RAT in a given geographic area to avoid interference between wireless networks of different RATs. In some cases, NR or 5G RAT networks may be deployed.

[0049] In some examples, two or more UEs 120 (e.g., shown as UE 120a and UE 120e) may communicate directly using one or more sidelink channels (e.g., without using network node 110 as an intermediary to communicate with each other). For example, UE 120 may communicate using peer-to-peer (P2P) communication, device-to-device (D2D) communication, vehicle-to-everything (V2X) protocols (e.g., which may include vehicle-to-vehicle (V2V) protocols, vehicle-to-infrastructure (V2I) protocols, or vehicle-to-pedestrian (V2P) protocols), or mesh networks. In such examples, UE 120 may perform scheduling operations, resource selection operations, or other operations described elsewhere herein as being performed by network node 110.

[0050] The devices of the wireless network 100 may communicate using an electromagnetic spectrum, which may be subdivided into various categories, bands, or channels by frequency or wavelength. For example, the devices of the wireless network 100 may communicate using one or more operating bands. In 5G NR, two initial operating bands have been identified as frequency ranges designated FR1 (410 MHz-7.125 GHz) and FR2 (24.25 GHz-52.6 GHz). Although a portion of FR1 is greater than 6 GHz, FR1 is often (interchangeably) referred to as the "below 6 GHz" band in various documents and articles. Similar naming issues sometimes arise in conjunction with FR2, which is often (interchangeably) referred to as the "millimeter wave" band in various documents and articles, although it is different from the extremely high frequency (EHF) band (30 GHz-300 GHz) identified as the "millimeter wave" band by the International Telecommunication Union (ITU).

[0051] Frequencies between FR1 and FR2 are generally referred to as mid-band frequencies. Recent 5G NR research has identified the operating bands for these mid-band frequencies as frequency range designation FR3 (7.125GHz-24.25GHz). The bands falling within FR3 can inherit FR1 characteristics or FR2 characteristics, and thus the features of FR1 or FR2 can be effectively extended to mid-band frequencies. In addition, currently exploring higher frequency bands to extend 5G NR operation to more than 52.6GHz. For example, three higher operating bands have been identified as frequency range designations FR4a or FR4-1 (52.6GHz-71GHz), FR4 (52.6GHz-114.25GHz) and FR5 (114.25GHz-300GHz). Each of these higher frequency bands falls within the EHF band.

[0052] Considering the above examples, unless otherwise specifically stated, if the term "sub-6 GHz" is used herein, it may broadly refer to frequencies that may be less than 6 GHz, may be within FR1, or may include mid-band frequencies. In addition, unless otherwise specifically stated, if the term "millimeter wave" is used herein, it may broadly refer to frequencies that may include mid-band frequencies, may be within FR2, FR4, FR4-a, FR4-1, or FR5, or may be within the EHF band. It is contemplated that the frequencies included in these operating bands (e.g., FR1, FR2, FR3, FR4, FR4-a, FR4-1, or FR5) may be modified, and the techniques described herein are applicable to those modified frequency ranges.

[0053] In some aspects, UE 120 may include a communications manager 140 . As described in more detail elsewhere herein, the communications manager 140 may receive an indication of a first TAG associated with a first radio link of a serving cell and a second TAG associated with a second radio link of the serving cell; send a first random access channel (RACH) message on the serving cell based at least in part on a failure of a BFR process associated with at least one of a first beam failure detection (BFD) RS set associated with the first radio link or a second BFD-RS set associated with the second radio link; receive a second RACH message indicating a TAC for the serving cell based at least in part on sending the first RACH message; and communicate with the serving cell based at least in part on an application of the TAC to the first TAG or the second TAG, the application of the TAC to the first TAG or the second TAG being based at least in part on one or more of: whether a new candidate beam associated with the first radio link or the second radio link is identified prior to sending the first RACH message; a BFD-RS set in the first BFD-RS set or the second BFD-RS set that is not the at least one BFD-RS set for which a BFR process is not triggered; or an SSB associated with the first RACH message. Additionally or alternatively, the communications manager 140 may perform one or more other operations described herein.

[0054] Figure 2 is a diagram illustrating an example network node communicating with a UE in a wireless network according to the present disclosure. The network node may correspond to Figure 1 Similarly, the UE may correspond to a network node 110. Figure 1 UE 120. Network node 110 may be equipped with a set of antennas 234a to 234t, such as T antennas (T ≥ 1). UE 120 may be equipped with a set of antennas 252a to 252r, such as R antennas (R ≥ 1). Figure 2 The network node 110 depicted in FIG. 1 includes one or more radio frequency components, such as an antenna 234 and a modem 254. In some examples, the network node 110 may include an interface, a communication component, or another component that facilitates communication with the UE 120 or another network node. Some network nodes 110 may not include radio frequency components that facilitate direct communication with the UE 120, such as one or more CUs or one or more DUs.

[0055] At the network node 110, the transmit processor 220 may receive data intended for the UE 120 (or a set of UEs 120) from the data source 212. The transmit processor 220 may select one or more modulation and coding schemes (MCS) for the UE 120 based at least in part on one or more channel quality indicators (CQIs) received from the UE 120. The network node 110 may process (e.g., encode and modulate) the data for the UE 120 based at least in part on the MCS selected for the UE 120, and may provide data symbols for the UE 120. The transmit processor 220 may process system information (e.g., for semi-static resource partitioning information (SRPI)) and control information (e.g., CQI requests, grants, or upper layer signaling), and provide overhead symbols and control symbols. The transmit processor 220 may generate reference symbols for reference signals (e.g., cell-specific reference signals (CRS) or demodulation reference signals (DMRS)) and synchronization signals (e.g., primary synchronization signals (PSS) or secondary synchronization signals (SSS)). The transmit (TX) multiple-input multiple-output (MIMO) processor 230 may perform spatial processing (e.g., pre-coding) on ​​data symbols, control symbols, overhead symbols, or reference symbols, where applicable, and may provide a set of output symbol streams (e.g., T output symbol streams) to a corresponding set of modems 232 (e.g., T modems) (shown as modems 232a to 232t). For example, each output symbol stream may be provided to a modulator component (shown as MOD) of the modem 232. Each modem 232 may process a corresponding output symbol stream (e.g., for OFDM) using a corresponding modulator component to obtain an output sample stream. Each modem 232 may also process (e.g., convert to analog, amplify, filter, or up-convert) the output sample stream using a corresponding modulator component to obtain a downlink signal. The modems 232a to 232t may transmit a set of downlink signals (e.g., T downlink signals) via a corresponding set of antennas 234 (e.g., T antennas) (shown as antennas 234a to 234t).

[0056] At the UE 120, a set of antennas 252 (shown as antennas 252a to 252r) may receive downlink signals from the network node 110 or other network nodes 110, and may provide a set of received signals (e.g., R received signals) to a set of modems 254 (e.g., R modems) (shown as modems 254a to 254r). For example, each received signal may be provided to a demodulator component (shown as DEMOD) of the modem 254. Each modem 254 may use a corresponding demodulator component to condition (e.g., filter, amplify, downconvert, or digitize) the received signal to obtain input samples. Each modem 254 may use a demodulator component to further process the input samples (e.g., for OFDM) to obtain received symbols. A MIMO detector 256 may obtain received symbols from the modem 254, may perform MIMO detection on the received symbols where applicable, and may provide detected symbols. The receive processor 258 may process (e.g., demodulate and decode) the detected symbols, may provide decoded data for the UE 120 to the data sink 260, and may provide decoded control information and system information to the controller / processor 280. The term "controller / processor" may refer to one or more controllers or one or more processors. The channel processor may determine a reference signal received power (RSRP) parameter, a received signal strength indicator (RSSI) parameter, a reference signal received quality (RSRQ) parameter, or a CQI parameter, among other things. In some examples, one or more components of the UE 120 may be included in a housing.

[0057] The network controller 130 may include a communication unit 294, a controller / processor 290, and a memory 292. The network controller 130 may include, for example, one or more devices in a core network. The network controller 130 may communicate with the network node 110 via the communication unit 294.

[0058] One or more antennas (e.g., antennas 234a to 234t or antennas 252a to 252r) may include or may be included in one or more antenna panels, one or more antenna groups, one or more sets of antenna elements, or one or more antenna arrays, etc. An antenna panel, antenna group, set of antenna elements, or antenna array may include one or more antenna elements (in a single housing or multiple housings), a set of coplanar antenna elements, a set of non-coplanar antenna elements, or coupled to one or more transmit or receive components (such as Figure 2 One or more antenna elements of one or more components).

[0059] On the uplink, at the UE 120, the transmit processor 264 may receive and process data from the data source 262 and control information from the controller / processor 280 (e.g., for reports including RSRP, RSSI, RSRQ, or CQI). The transmit processor 264 may generate reference symbols for one or more reference signals. The symbols from the transmit processor 264 may be pre-decoded by the TX MIMO processor 266, where applicable, further processed by the modem 254 (e.g., for DFT-s-OFDM or CP-OFDM), and sent to the network node 110. In some examples, the modem 254 of the UE 120 may include a modulator and a demodulator. In some examples, the UE 120 includes a transceiver. The transceiver may include any combination of an antenna 252, a modem 254, a MIMO detector 256, a receive processor 258, a transmit processor 264, or a TX MIMO processor 266. The transceiver may be used by a processor (eg, controller / processor 280) and memory 282 to perform aspects of any of the methods described herein.

[0060] At the network node 110, uplink signals from the UE 120 or other UEs may be received by the antenna 234, processed by the modem 232 (e.g., a demodulator component of the modem 232, shown as DEMOD), detected by the MIMO detector 236 where applicable, and further processed by the receive processor 238 to obtain decoded data and control information transmitted via the UE 120. The receive processor 238 may provide the decoded data to the data sink 239 and provide the decoded control information to the controller / processor 240. The network node 110 may include a communication unit 244 and may communicate with the network controller 130 via the communication unit 244. The network node 110 may include a scheduler 246 to schedule one or more UEs 120 for downlink or uplink communication. In some examples, the modem 232 of the network node 110 may include a modulator and a demodulator. In some examples, the network node 110 includes a transceiver. The transceiver may include any combination of an antenna 234, a modem 232, a MIMO detector 236, a receive processor 238, a transmit processor 220, or a TX MIMO processor 230. The transceiver may be used by a processor (e.g., controller / processor 240) and memory 242 to perform aspects of any of the methods described herein.

[0061] The controller / processor 240 of the network node 110, the controller / processor 280 of the UE 120, or Figure 2Any other component of the network node 110 may perform one or more techniques associated with applying the TAC of the access channel message to a TAG in the plurality of TAGs, as described in more detail elsewhere herein. For example, the controller / processor 240 of the network node 110, the controller / processor 280 of the UE 120, or Figure 2 Any other component of the can perform or direct e.g. Fig.12 1200 or other processes as described herein. Memory 242 and memory 282 may store data and program codes for network node 110 and UE 120, respectively. In some examples, memory 242 or memory 282 may include a non-transitory computer-readable medium storing one or more instructions (e.g., code or program code) for wireless communication. For example, the one or more instructions, when executed by one or more processors of network node 110 or UE 120 (e.g., directly executed, or executed after compilation, conversion, or interpretation), may cause one or more processors, UE 120, or network node 110 to perform or direct, for example, Fig.12 The operations of process 1200 or other processes as described herein. In some examples, executing instructions may include running instructions, converting instructions, compiling instructions, or interpreting instructions, etc.

[0062] In some aspects, the UE includes a component for receiving an indication of a first TAG associated with a first radio link of a serving cell and a second TAG associated with a second radio link of the serving cell; a component for sending a first random access channel (RACH) message on the serving cell based at least in part on a failure of a BFR process associated with at least one BFD-RS set from a first BFD-RS set associated with the first radio link or a second BFD-RS set associated with the second radio link; a component for receiving a second RACH message indicating a TAC for the serving cell based at least in part on sending the first RACH message; or a component for communicating with the serving cell based at least in part on an application of the TAC to the first TAG or the second TAG, the application of the TAC to the first TAG or the second TAG being based at least in part on one or more of: whether a new candidate beam associated with the first radio link or the second radio link is identified prior to sending the first RACH message; a BFD-RS set in the first BFD-RS set or the second BFD-RS set that is not the at least one BFD-RS set for which the BFR process is not triggered; or an SSB associated with the first RACH message. Means for the UE to perform operations described herein may include, for example, one or more of the following: communications manager 140, antenna 252, modem 254, MIMO detector 256, receive processor 258, transmit processor 264, TX MIMO processor 266, controller / processor 280, or memory 282.

[0063] The deployment of a communication system (such as a 5G NR system) can be arranged with various components or components in a variety of ways. In a 5G NR system or network, a network node, a network entity, a mobility element of a network, a RAN node, a core network node, a network element, a base station or network equipment can be implemented in an aggregated or decomposed architecture. For example, a base station (such as a node B (NB), an evolved NB (eNB), an NR BS, a 5G NB, an access point (AP), a TRP or a cell, etc.) or one or more units (or one or more components) that perform base station functionality can be implemented as an aggregated base station (also called an independent base station or a monolithic base station) or a decomposed base station. A "network entity" or a "network node" may refer to a decomposed base station or one or more units of a decomposed base station (such as one or more CUs, one or more DUs or one or more RUs).

[0064] An aggregated base station (e.g., an aggregated network node) may be configured to utilize a radio protocol stack that is physically or logically integrated within a single RAN node (e.g., within a single device or unit). A decomposed base station (e.g., a decomposed network node) may be configured to utilize a protocol stack that is physically or logically distributed between two or more units (such as one or more CUs, one or more DUs, or one or more RUs). In some examples, a CU may be implemented within a network node, and one or more DUs may be co-located with the CU, or alternatively, may be geographically or virtually distributed across one or more other network nodes. A DU may be implemented to communicate with one or more RUs. Each of a CU, a DU, and a RU may also be implemented as a virtual unit, such as a virtual central unit (VCU), a virtual distributed unit (VDU), or a virtual radio unit (VRU), and the like.

[0065] Base station type operations or network designs may take into account the aggregated nature of base station functionality. For example, a decomposed base station may be utilized in an IAB network, an open radio access network (O-RAN (such as a network configuration initiated by the O-RAN Alliance)), or a virtualized radio access network (vRAN, also known as a cloud radio access network (C-RAN)) to facilitate the scaling of a communication system by separating base station functionality into one or more units that can be deployed separately. A decomposed base station may include functionality implemented across two or more units at various physical locations, as well as functionality implemented virtually for at least one unit, which may enable flexibility in network design. Individual units of a decomposed base station may be configured for wired or wireless communication with at least one other unit of the decomposed base station.

[0066] Figure 33 is a diagram illustrating an example disaggregated base station architecture 300 according to the present disclosure. The disaggregated base station architecture 300 may include a CU 310 that may communicate directly with a core network 320 via a backhaul link, or indirectly with the core network 320 through one or more disaggregated control units, such as a near-RT RIC 325 via an E2 link, or a non-RT RIC 315 associated with a service management and orchestration (SMO) framework 305, or both. The CU 310 may communicate with one or more DUs 330 via respective midhaul links, such as via an F1 interface. Each of the DUs 330 may communicate with one or more RUs 340 via respective fronthaul links. Each of the RUs 340 may communicate with one or more UEs 120 via respective radio frequency (RF) access links. In some implementations, a UE 120 may be served simultaneously by multiple RUs 340.

[0067] Each of the units (including CU 310, DU 330, RU 340) and the near-RT RIC 325, non-RT RIC 315, and SMO framework 305 may include or be coupled to one or more interfaces, the one or more interfaces being configured to receive or send signals, data, or information (collectively referred to as signals) via a wired or wireless transmission medium. Each of the units or an associated processor or controller that provides instructions to one or more communication interfaces of the corresponding unit may be configured to communicate with one or more of the other units via a transmission medium. In some examples, each of the units may include a wired interface and a wireless interface, the wired interface being configured to receive signals or send signals to one or more of the other units via a wired transmission medium, the wireless interface being configured to receive signals or send signals to one or more of the other units via a wired transmission medium, and the wireless interface being configured to receive signals or send signals to one or more of the other units via a wireless transmission medium, or to do both.

[0068] In some aspects, the CU 310 may host one or more higher layer control functions. Such control functions may include RRC functions, packet data convergence protocol (PDCP) functions, or service data adaptation protocol (SDAP) functions, etc. Each control function may be implemented using an interface that is configured to communicate signals with other control functions hosted by the CU 310. The CU 310 may be configured to handle user plane functionality (e.g., central unit-user plane (CU-UP) functionality) or control plane functionality (e.g., central unit-control plane (CU-CP) functionality). In some specific implementations, the CU 310 may be logically divided into one or more CU-UP units and one or more CU-CP units. When implemented in an O-RAN configuration, the CU-UP unit may communicate bidirectionally with the CU-CP unit via an interface (such as an E1 interface). As needed, the CU 310 may be implemented to communicate with the DU 330 for network control and signaling.

[0069] Each DU 330 may correspond to a logical unit that includes one or more base station functions for controlling the operation of one or more RUs 340. In some aspects, the DU 330 may host one or more of a radio link control (RLC) layer, a MAC layer, and one or more high physical (PHY) layers, at least in part, according to a functional partitioning (such as that defined by 3GPP). In some aspects, one or more high PHY layers may be implemented by one or more modules for forward error correction (FEC) encoding and decoding, scrambling, modulation and demodulation, etc. In some aspects, the DU 330 may also host one or more low PHY layers, such as one or more modules for fast Fourier transform (FFT), inverse FFT (iFFT), digital beamforming or physical random access channel (PRACH) extraction and filtering, etc. Each layer (which may also be referred to as a module) may be implemented using an interface that is configured to communicate signals with other layers (and modules) hosted by the DU 330 or with control functions hosted by the CU 310.

[0070] Each RU 340 may implement lower layer functionality. In some deployments, the RU 340 controlled by the DU 330 may correspond to a logical node that hosts RF processing functions or low PHY layer functions based on functional split (e.g., functional split defined by 3GPP) (such as lower layer functional split), such as performing FFT, performing iFFT, digital beamforming, or PRACH extraction and filtering, etc. In this architecture, each RU 340 may be operated to handle over-the-air (OTA) communications with one or more UEs 120. In some specific implementations, real-time and non-real-time aspects of control plane communications and user plane communications with the RU 340 may be controlled by the corresponding DU 330. In some scenarios, this configuration may enable each DU 330 and CU 310 to be implemented in a cloud-based RAN architecture (such as a vRAN architecture).

[0071] The SMO framework 305 may be configured to support RAN deployment and provisioning of non-virtualized network elements and virtualized network elements. For non-virtualized network elements, the SMO framework 305 may be configured to support the deployment of dedicated physical resources for RAN coverage requirements, which may be managed via an operation and maintenance interface (such as an O1 interface). For virtualized network elements, the SMO framework 305 may be configured to interact with a cloud computing platform (such as an open cloud (O-Cloud) platform 390) to perform network element lifecycle management (such as instantiating virtualized network elements) via a cloud computing platform interface (such as an O2 interface). Such virtualized network elements may include, but are not limited to, CU 310, DU 330, RU 340, non-RT RIC 315, and near-RTRIC 325. In some specific implementations, the SMO framework 305 may communicate with hardware aspects of the 4G RAN (such as an open eNB (O-eNB) 311) via the O1 interface. Additionally, in some implementations, the SMO framework 305 can communicate directly with each of the one or more RUs 340 via a corresponding O1 interface. The SMO framework 305 can also include a non-RT RIC 315 configured to support the functionality of the SMO framework 305.

[0072] The non-RT RIC 315 may be configured to include logic functions that enable non-real-time control and optimization of RAN elements and resources, artificial intelligence / machine learning (AI / ML) workflows including model training and updating, or policy-based guidance of applications / features in the near-RT RIC 325. The non-RT RIC 315 may be coupled to or in communication with the near-RT RIC 325 (such as via an A1 interface). The near-RT RIC 325 may be configured to include logic functions that enable near-real-time control and optimization of RAN elements and resources via data collection and actions through an interface (such as via an E2 interface) that connects one or more CUs 310, one or more DUs 330, or both, and the O-eNB with the near-RT RIC 325.

[0073] In some implementations, in order to generate an AI / ML model to be deployed in the near-RT RIC 325, the non-RT RIC 315 may receive parameters or external enrichment information from an external server. Such information may be utilized by the near-RT RIC 325 and may be received from a non-network data source or from a network function at the SMO framework 305 or the non-RT RIC 315. In some examples, the non-RT RIC 315 or the near-RT RIC 325 may be configured to tune RAN behavior or performance. For example, the non-RT RIC 315 may monitor long-term trends and patterns of performance and employ AI / ML models to perform corrective actions through the SMO framework 305 (such as via reconfiguration of the O1 interface) or via the creation of RAN management policies (such as A1 interface policies).

[0074] Figure 4 4 is a diagram illustrating an example 400 of a beam failure recovery process according to the present disclosure. Figure 4 As shown, the UE can communicate with a network node (e.g., associated with a primary cell), a first TRP associated with a first wireless link to a serving cell, and a second TRP associated with a second wireless link to the serving cell.

[0075] As shown in the first operation 405, the UE may detect a beam failure associated with the first TRP and the first radio link. BFD may be a per-TRP operation. The associated BFD-RS set, NBI-RS set, BFD count, and BFD timer may also be per-TRP (e.g., TRP-specific).

[0076] In some examples, the UE may identify an implicit BFD-RS set for a multi-DCI communication scheme. For example, a BFD-RS set k (k = 0, 1) may be derived based at least in part on the X TCI of a CORESET, where CORESETPoolIndex = k. If the number of CORESET TCI states per TRP exceeds the UE capability for the maximum number of BFD-RS resources per set, the UE may reuse the radio link monitoring (RLM) RS selection rule.

[0077] In some examples, the UE may identify an explicit BFD-RS set for a multiple DCI communication scheme. For example, the explicit BFD-RS set may be configured using radio resource control (RRC) signaling.

[0078] As shown in the second operation 410, the UE may send and the network node may receive a physical uplink control channel (PUCCH)-BFR indication associated with a first TRP (BFR_0). In some networks, the UE may select a PUCCH-BFR resource for sending the indication. For example, two PUCCH-BFR resources may be configured per PUCCH group. The UE may select a PUCCH-BFR resource associated with a first TRP (e.g., a TRP associated with BFD).

[0079] The UE may receive, and the network node may send, an uplink grant as shown in a third operation 415. The uplink grant may provide the UE with resources for sending additional information in a medium access control (MAC) control element (CE).

[0080] As shown in the fourth operation 420, the UE may send a BFR MAC CE. The BFR MAC CE may carry a BFR request (BFRQ) for all TRPs in all component carriers in the cell group. The BFRQ may include an index of a failed BFD-RS set (e.g., as an indication of a failed TRP link), an index of a component carrier containing a failed TRP link (e.g., a TRP link for which a beam failure was detected), an indication of whether a new candidate beam is identified in an NBI-RS set associated with the failed BFD-RS set, or a resource indicator associated with the new candidate beam (e.g., if identified).

[0081] The UE may receive and the network node may send a BFR response as shown in a fifth operation 425. The BFR response may include an uplink grant that schedules subsequent transmission of the same hybrid automatic repeat request (HARQ) identifier as the BFR MAC CE.

[0082] As shown in the sixth operation 430, the UE may reset the new beam. For example, the UE and the first TRP may reset the new beam for the CORESET of the CORESETPoolIndex associated with the first TRP. In some networks, after 28 symbols from the receipt of the BFR response, the beams of all CORESETs associated with the CORESETPoolIndex associated with the first TRP (e.g., the failed TRP) are reset to the corresponding new candidate beams reported.

[0083] As shown in the seventh operation 435, the UE may detect a beam failure associated with the second TRP and the second radio link. BFD may be a per-TRP operation. The associated BFD-RS set, NBI-RS set, BFD count, and BFD timer may also be per-TRP (e.g., TRP-specific).

[0084] In some examples, the UE may identify an implicit BFD-RS set for a multi-DCI communication scheme. For example, a BFD-RS set k (k = 0, 1) may be derived based at least in part on the X TCI of a CORESET, where CORESETPoolIndex = k. If the number of CORESET TCI states per TRP exceeds the UE capability for the maximum number of BFD-RS resources per set, the UE may reuse the radio link monitoring (RLM) RS selection rule.

[0085] In some examples, the UE may identify an explicit BFD-RS set for a multiple DCI communication scheme. For example, the explicit BFD-RS set may be configured using RRC signaling.

[0086] As shown in the eighth operation 440, the UE may send and the network node may receive a PUCCH-BFR indication associated with the second TRP (BFR_1). In some networks, the UE may select a PUCCH-BFR resource for sending the indication. For example, each PUCCH group may be configured with two PUCCH_BFR resources. The UE may select a PUCCH-BFR resource associated with the second TRP (e.g., a TRP associated with BFD).

[0087] The UE may receive, and the network node may send, an uplink grant as shown in a ninth operation 445. The uplink grant may provide the UE with resources for sending additional information in a MAC CE.

[0088] As shown in the tenth operation 450, the UE may send a BFR MAC CE. The BFR MAC CE may carry a BFRQ for all TRPs in all component carriers in the cell group. The BFRQ may include an index of a failed BFD-RS set (e.g., as an indication of a failed TRP link), an index of a component carrier containing a failed TRP link (e.g., a TRP link where a beam failure was detected), an indication of whether a new candidate beam is identified in an NBI-RS set associated with the failed BFD-RS set, or a resource indicator associated with the new candidate beam (e.g., if identified).

[0089] The UE may receive and the network node may send a BFR response as shown in an eleventh operation 455. The BFR response may include an uplink grant that schedules a subsequent transmission of the same hybrid automatic repeat request (HARQ) identifier as the BFR MAC CE.

[0090] As shown in the twelfth operation 460, the UE may reset the new beam. For example, the UE and the second TRP may reset the new beam for the CORESET of the CORESET pool index associated with the second TRP. In some networks, after 28 symbols from the receipt of the BFR response, the beams of all CORESETs associated with the CORESETPoolIndex associated with the second TRP (e.g., the failed TRP) are reset to the corresponding new candidate beams reported.

[0091] In some networks, if the serving cell is configured with two BFD-RS sets, if the BFR procedure is triggered for both BFD-RS sets of the serving cell (e.g., SpCell) and the BFR procedure is not successfully completed for any BFD-RS set, the UE may initiate a random access procedure on the serving cell. Additionally or alternatively, as long as at least one SR is pending, the MAC entity of the UE may initiate a random access procedure on the SpCell for each pending scheduling request, and cancel the pending SR if the MAC entity does not configure a valid PUCCH resource for the pending SR.

[0092] Figure 5 5 is a diagram illustrating an example 500 of a four-step random access procedure according to the present disclosure. Figure 5 As shown, the network node 110 and the UE 120 may communicate with each other to perform a four-step random access procedure.

[0093] As shown in the first operation 505, the network node 110 may send and the UE 120 may receive one or more SSBs and random access configuration information. In some aspects, the random access configuration information may be sent or indicated by system information (e.g., in one or more system information blocks (SIBs)) or SSBs, such as for contention-based random access. Additionally or alternatively, the random access configuration information may be sent in an RRC message or a physical downlink control channel (PDCCH) command message that triggers a RACH procedure, such as for contention-free random access. The random access configuration information may include one or more parameters to be used in the random access procedure, such as one or more parameters for sending a RAM or one or more parameters for receiving a RAR.

[0094] As shown in the second operation 510, the UE 120 may send a RAM, which may include a preamble (sometimes referred to as a random access preamble, a PRACH preamble, or a RAM preamble). The message including the preamble may be referred to as message 1, msg1, MSG1, a first message, or an initial message in the four-step random access process. The random access message may include a random access preamble identifier.

[0095] As shown in the third operation 515, the network node 110 may send a RAR as a response to the preamble. The message including the RAR may be referred to as message 2, msg2, MSG2, or a second message in the four-step random access procedure. In some aspects, the RAR may indicate a detected random access preamble identifier (e.g., received from the UE 120 in msg1). Additionally or alternatively, the RAR may indicate a resource allocation to be used by the UE 120 to send message 3 (msg3).

[0096] In some aspects, as part of the second step of the four-step random access procedure, the network node 110 may send a PDCCH communication for the RAR. The PDCCH communication may schedule a PDSCH communication including the RAR. For example, the PDCCH communication may indicate a resource allocation for the PDSCH communication. Also as part of the second step of the four-step random access procedure, the network node 110 may send a PDSCH communication for the RAR as scheduled by the PDCCH communication. The RAR may be included in the MAC PDU of the PDSCH communication. The RAR may include an indication of the TAC for subsequent communications.

[0097] As shown in the fourth operation 520, UE 120 may send an RRC connection request message. The RRC connection request message may be referred to as message 3, msg3, MSG3, or the third message of the four-step random access procedure. In some aspects, the RRC connection request may include a UE identifier, a UCI, or a PUSCH communication (e.g., an RRC connection request). The RRC connection request may include an index of a component carrier that includes a failed TRP link. In some examples, the RRC connection request may indicate a failed BFR set identifier, an NBI presence, or an NBI for each TRP (e.g., a first TRP and a second TRP).

[0098] As shown in the fifth operation 525, the network node 110 may send an RRC connection setup message. The RRC connection setup message may be referred to as message 4, msg4, MSG4, or a fourth message of the four-step random access procedure. In some aspects, the RRC connection setup message may include a detected UE identifier, a timing advance value, or contention resolution information. As shown in the sixth operation 530, if the UE 120 successfully receives the RRC connection setup message, the UE 120 may send a HARQ ACK.

[0099] Based at least in part on the UE receiving the TAC in msg2 and without an indication of which TAG the UE is to apply the TAC to, the UE and the network node may be out of sync. This may cause the UE to apply the TAC to an unintended TAG, which may cause the UE and the network node to communicate with reduced timing synchronization, increased error rates, and reduced spectral efficiency. Additionally or alternatively, the UE and the network node may consume power, computing, network, and communication resources to detect and correct errors associated with applying the TAC to an unintended TAG.

[0100] Various aspects generally relate to applying a timing advance command (TAC) indicated during a random access procedure to a first TAG or a second TAG. Some aspects more specifically relate to communicating based at least in part on the application of the TAC to the first TAG or the second TAG in a multiple transmit-receive point (TRP) scenario. In some aspects, a UE may initiate a random access procedure after a beam failure recovery (BFR) procedure fails.

[0101] In some aspects, the UE may apply the TAC to the first TAG based at least in part on a failure to identify any new candidate beams for any NBI RS set when sending the first random access message. For example, the UE may apply the TAC to the first TAG based at least in part on the first TAG being associated with a first TAG associated with a first TAG index, a lowest TAG identity relative to a second TAG identity associated with a second TAG, or being associated with a default CORESET pool index, etc.

[0102] In some aspects, the UE may apply the TAC to the first TAG based at least in part on identifying a new candidate beam in the NBI-RS set when sending the first random access message. For example, the UE may apply the TAC to the first TAG based at least in part on the first TAG being associated with the NBI-RS set in which the UE identifies the new candidate beam.

[0103] In some aspects, the UE may apply the TAC to the first TAG based at least in part on the UE selecting an SSB from an NBI-RS set associated with the first TAG. In some aspects, when sending a first random access message, the UE may identify a first new candidate beam in a first NBI-RS set associated with the first TAG and a second new candidate beam in a second NBI-RS set associated with the second TAG.

[0104] For example, the UE may apply the TAC to the first TAG based at least in part on associating the first TAG with the NBI-RS set to which the selected SSB belongs. The SSB may belong to the NBI-RS set based at least in part on being received on a beam within the NBI-RS set.

[0105] In some aspects, the UE may apply the TAC to the first TAG based at least in part on not triggering a BFR procedure for a BFD-RS set associated with the first TAG. For example, the UE may apply the TAC to the first TAG based at least in part on triggering a BFR procedure for a BFD-RS set associated with the second TAG.

[0106] In some aspects, the UE may apply the TAC to the first TAG based at least in part on the same CORESET pool index being associated with the first TAG and the SSB associated with the first random access message or the first TAG being associated with the SSB associated with the first random access message.

[0107] Certain aspects of the subject matter described in the present disclosure may be implemented to achieve one or more of the following potential advantages. In some examples, the described techniques may be used to synchronize the application of a TAC to one of a plurality of TAGs between a UE and a network node, where the TAGs are associated with different TRPs or radio links of a serving cell. In this way, the UE may apply the TAC to an expected TAG (e.g., expected by a network node) for configuring the timing of communications using the expected TAG and associated communication links or beams. Based at least in part on applying the TAC to the expected TAG, the UE and the network node may have improved timing synchronization, reduced error rates, and improved spectral efficiency. In this way, the UE and the network node may save power, computing, network, and communication resources that would otherwise be used to detect and correct errors associated with applying the TAC to an unexpected TAG.

[0108] Figure 6 6 is a diagram of an example 600 associated with applying a TAC of an access channel message to a TAG among a plurality of TAGs according to the present disclosure. Figure 6 As shown, a network node (e.g., network node 110, CU, DU, or RU) can communicate with a UE (e.g., UE 120). In some aspects, the network node and the UE can be part of a wireless network (e.g., wireless network 100). The UE and the network node can be in Figure 6 The operations shown are performed after a wireless connection has been established.

[0109] As shown in the first operation 605, the network node may send and the UE may receive configuration information. In some aspects, the UE may receive the configuration information via one or more of RRC signaling, one or more MAC CEs, or downlink control information (DCI), etc. In some aspects, the configuration information may include an indication of one or more configuration parameters for the UE to select (e.g., known to the UE or previously indicated by the network node or other network device) or explicit configuration information for the UE to configure the UE, etc.

[0110] In some aspects, the configuration information may indicate that the UE will send an indication of the ability to select a TAG to which the UE will apply a TAC received during a random access procedure in a multi-TAG communication scheme. In some aspects, the configuration information may indicate one or more operations or rules for the UE to select a TAG to which the UE will apply a TAC received during a random access procedure.

[0111] The UE may configure itself based at least in part on the configuration information.In some aspects, the UE may be configured to perform one or more operations described herein based at least in part on the configuration information.

[0112] The UE may send, and the network node may receive, a capability report as shown in a second operation 610. In some aspects, the capability report may indicate that the UE supports selecting a TAG to which the UE is to apply a TAC received during a random access procedure in a multi-TAG communication scheme.

[0113] As shown in the third operation 615, the UE may receive and the network node may send the RS. The RS may be associated with time synchronization. For example, the RS may include a channel state information reference signal (CSI-RS) or a tracking reference signal (TRS) that the UE may measure to determine timing information. For example, the timing information may include information associated with propagation delay or timing advance (TA).

[0114] As shown in the fifth operation 620, the UE may receive and the network node may send an indication of a first TAG for a first radio link and a second TAG for a second radio link. The first radio link may be associated with a first TRP and a first CORESET. The second radio link may be associated with a second TRP and a second CORESET. The first TAG and the second TAG may be nodes of a serving cell.

[0115] In some aspects, a first TAG may be associated with a first NBI-RS set or a first BFD-RS set, and a second TAG may be associated with a second NBI-RS set or a second BFD-RS set. In some aspects, the association of the TAG with the NBI-RS set or the BFD-RS set may be based at least in part on the TAG and the NBI-RS set or the BFD-RS set being associated with the same CORESET pool index value. In some aspects, the association of the TAG with the NBI-RS set or the BFD-RS set may be based at least in part on a mapping rule (e.g., in a communication protocol or RRC configuration, etc.), or the first TAG is configured for the first NBI-RS set or the first BFD-RS set.

[0116] In some aspects, the first TAG may be configured for the first NBI-RS set or in the first BFD-RS set based at least in part on the configuration of the TAG identifier of the first TAG to the first NBI-RS set or the first BFD-RS set or to each RS in the first NBI-RS set or the first BFD-RS set.

[0117] As shown in the sixth operation 625, the UE may identify a beam failure. For example, the UE may identify a beam failure for the first radio link, the first TRP, and the first CORESET pool index. Additionally or alternatively, the UE may identify a beam failure for the second radio link, the second TRP, and the second CORESET pool index.

[0118] As shown in the seventh operation 630, the UE may attempt a BFR procedure associated with at least one BFD-RS set from a first BFD-RS set associated with the first radio link or a second BFD-RS set associated with the second radio link. For example, the UE may trigger the BFR procedure and determine whether the resources allow the UE to send PUCCH_BFR0, as in conjunction with Figure 4 As described.

[0119] In some aspects, the BFR process may be associated with at least one BFD-RS set from a first BFD-RS set associated with the first radio link or a second BFD-RS set associated with the second radio link.

[0120] The UE may identify or fail to identify one or more new candidate beams as shown in an eighth operation 635. For example, the UE may identify one or more new candidate beams for one BFD-RS set, two BFD-RS sets, or not for both BFD-RS sets.

[0121] The UE may send, and the network node may receive, a first RACH message, as shown in a ninth operation 640. In some aspects, the UE may send the first RACH message on the serving cell based at least in part on a failure of the BFR procedure.

[0122] As shown in the tenth operation 645, the UE may receive and the network node may send a second RACH message indicating the TAC. The TAC may be associated with a serving cell that is associated with the first TRP and the second TRP.

[0123] As shown in an eleventh operation 650, the UE may TAC an application to the first TAG or the second TAG.

[0124] In some aspects (e.g., where the UE fails to identify any new candidate beams prior to transmission of the first RACH message), the UE may apply the TAC to the first TAG based at least in part on the failure to identify new candidate beams for any NBI-RS set prior to transmission of the first RACH message and at least in part on the first TAG being a default TAG. In some aspects, the first TAG may be a default TAG based at least in part on the first TAG being associated with a first TAG associated with a first TAG index, a lowest TAG identity relative to a second TAG identity associated with a second TAG, or being associated with a default CORESET pool index, etc.

[0125] In some aspects (e.g., where the UE identifies a new candidate beam for the NBI-RS set prior to sending the first RACH message), the UE may apply the TAC to the first TAG based at least in part on associating the first TAG with the NBI-RS set.

[0126] In some aspects (e.g., where the UE identifies a first new candidate beam for a first NBI-RS set and a second new candidate beam for a second NBI-RS set prior to transmission of a first RACH message), the UE may apply the TAC to the first TAG based at least in part on selecting an SSB associated with the first set of new candidate beams (e.g., a single first new candidate beam) and the first TAG being associated with the first NBI-RS set. In some aspects, the UE may signal the selection of the SSB to the network node (e.g., within the first RACH message).

[0127] In some aspects (e.g., where the application of the TAC is based at least in part on a BFD-RS set in the first BFD-RS set or a second BFD-RS set that is not the at least one BFD-RS set for which the BFR process is not triggered), the UE may apply the TAC to the first TAG based at least in part on the BFD-RS set associated with the first TAG not being associated with the BFR process.

[0128] In some aspects (e.g., where application of the TAC to the first TAG or the second TAG is based at least in part on an SSB associated with a first RACH message), the UE may apply the TAC to the first TAG based at least in part on the first TAG and the SSB associated with the first RACH being both associated with the same CORESET pool index or the first TAG being associated with the SSB associated with the first random access message. The CORESET pool index may also be associated with the first TRP and the first radio link.

[0129] As shown in the twelfth operation 655, the UE and the network node may communicate using the TAC. For example, the UE may communicate with a serving cell associated with the network node based at least in part on the application of the TAC to the first TAG or the second TAG. The application of the TAC to the first TAG or the second TAG may be based at least in part on: whether a new candidate beam associated with the first radio link or the second radio link is identified before the transmission of the first RACH message; a BFD-RS set in the first BFD-RS set or the second BFD-RS set that is not the at least one BFD-RS set for which the BFR process is not triggered; or an SSB associated with the first RACH message, etc.

[0130] Based at least in part on applying the TAC to the expected TAG, the UE and the network node can have improved timing synchronization, reduced error rates, and improved spectrum efficiency. In this way, the UE and the network node can save power, computing, network, and communication resources that would otherwise be used to detect and correct errors associated with applying the TAC to the unintended TAG.

[0131] Figure 7 is a diagram illustrating an example 700 of a four-step random access procedure according to the present disclosure. Figure 7 As shown, the network node 110 and the UE 120 may communicate with each other to perform a four-step random access procedure.

[0132] As shown in a first operation 705, the UE 120 may fail to identify a new candidate beam before sending a first random access message.

[0133] As shown in the second operation 710, the UE 120 may send a RAM, which may include a preamble (sometimes referred to as a random access preamble, a PRACH preamble, or a RAM preamble). The message including the preamble may be referred to as message 1, msg1, MSG1, a first message, or an initial message in the four-step random access process. The random access message may include a random access preamble identifier.

[0134] As shown in the third operation 715, the network node 110 may send a RAR as a response to the preamble. The message including the RAR may be referred to as message 2, msg2, MSG2, or a second message in the four-step random access procedure. In some aspects, the RAR may indicate a detected random access preamble identifier (e.g., received from the UE 120 in msg1). Additionally or alternatively, the RAR may indicate a resource allocation to be used by the UE 120 to send message 3 (msg3).

[0135] In some aspects, as part of the second step of the four-step random access procedure, the network node 110 may send a PDCCH communication for the RAR. The PDCCH communication may schedule a PDSCH communication including the RAR. For example, the PDCCH communication may indicate a resource allocation for the PDSCH communication. Also as part of the second step of the four-step random access procedure, the network node 110 may send a PDSCH communication for the RAR as scheduled by the PDCCH communication. The RAR may be included in the MAC PDU of the PDSCH communication. The RAR may include an indication of the TAC for subsequent communications.

[0136] As shown in the fourth operation 720, the UE 120 may identify a new candidate beam after receiving the RAR. In some aspects, based at least in part on not identifying any new candidate beams for any NBI-RS set when msg1 was sent, the TAC in the RAR may correspond to a fixed or configured TAG. For example, the TAC may apply to the first TAG of a serving cell (e.g., SpCell), the lowest TAG identifier of a serving cell, or a TAG associated with CORESETPoolIndex 0.

[0137] As shown in the fifth operation 725, UE 120 may send an RRC connection request message. The RRC connection request message may be referred to as message 3, msg3, MSG3, or the third message of the four-step random access procedure. In some aspects, the RRC connection request may include a UE identifier, a UCI, or a PUSCH communication (e.g., an RRC connection request). The RRC connection request may include an index of a component carrier that includes a failed TRP link. In some examples, the RRC connection request may indicate a failed BFR set identifier, an NBI presence, or an NBI for each TRP (e.g., a first TRP and a second TRP).

[0138] As shown in the sixth operation 730, the network node 110 may send an RRC connection establishment message. The RRC connection establishment message may be referred to as message 4, msg4, MSG4, or a fourth message of the four-step random access procedure. In some aspects, the RRC connection establishment message may include a detected UE identifier, a timing advance value, or contention resolution information. As shown in the seventh operation 735, if the UE 120 successfully receives the RRC connection establishment message, the UE 120 may send a HARQ ACK.

[0139] Figure 8 8 is a diagram illustrating an example 800 of a four-step random access procedure according to the present disclosure. Figure 8 As shown, the network node 110 and the UE 120 may communicate with each other to perform a four-step random access procedure.

[0140] As shown in a first operation 805, the UE 120 may identify new candidate beams for a first NBI-RS set before sending a first random access message.

[0141] As shown in the second operation 810, the UE 120 may send a RAM, which may include a preamble (sometimes referred to as a random access preamble, a PRACH preamble, or a RAM preamble). The message including the preamble may be referred to as message 1, msg1, MSG1, a first message, or an initial message in the four-step random access process. The random access message may include a random access preamble identifier.

[0142] As shown in the third operation 815, the network node 110 may send a RAR as a response to the preamble. The message including the RAR may be referred to as message 2, msg2, MSG2, or a second message in the four-step random access procedure. In some aspects, the RAR may indicate a detected random access preamble identifier (e.g., received from the UE 120 in msg1). Additionally or alternatively, the RAR may indicate a resource allocation to be used by the UE 120 to send message 3 (msg3).

[0143] In some aspects, as part of the second step of the four-step random access procedure, the network node 110 may send a PDCCH communication for the RAR. The PDCCH communication may schedule a PDSCH communication including the RAR. For example, the PDCCH communication may indicate a resource allocation for the PDSCH communication. Also as part of the second step of the four-step random access procedure, the network node 110 may send a PDSCH communication for the RAR as scheduled by the PDCCH communication. The RAR may be included in the MAC PDU of the PDSCH communication. The RAR may include an indication of the TAC for subsequent communications.

[0144] As shown in the fourth operation 820, the UE 120 may identify a new candidate beam for NBI-RS set 2 after receiving the RAR. In some aspects, based at least in part on identifying a new candidate beam for the first NBI-RS set before msg1 is sent, the TAC in the RAR may correspond to a TAG associated with the first NBI-RS set.

[0145] In some aspects, the first TAG can be associated with the first NBI-RS set based at least in part on a CORESET pool index (e.g., a CORESETPoolIndex value). For example, the first TAG can be associated with the first NBI-RS set based at least in part on the first TAG and the first NBI-RS being associated with a first CORESET pool index value (e.g., CORESETPoolIndex_0) or the second TAG and the second NBI-RS being associated with a second CORESET pool index value (e.g., CORESETPoolIndex_1).

[0146] In some aspects, a first TAG may be associated with a first NBI-RS set based at least in part on a rule. For example, based at least in part on a rule in a communication protocol or RRC configuration, a first TAG may be associated with a first NBI-RS set and a second TAG may be associated with a second NBI-RS set. In some aspects, a TAG identifier may be configured for each NBI-RS set, or a TAG identifier may be configured for each RS in an NBI-RS set. For example, an NBI-RS set may be associated with a TAG ID that is associated with the RSs in the NBI-RS set.

[0147] As shown in the fifth operation 825, UE 120 may send an RRC connection request message. The RRC connection request message may be referred to as message 3, msg3, MSG3, or the third message of the four-step random access procedure. In some aspects, the RRC connection request may include a UE identifier, a UCI, or a PUSCH communication (e.g., an RRC connection request). The RRC connection request may include an index of a component carrier that includes a failed TRP link. In some examples, the RRC connection request may indicate a failed BFR set identifier, an NBI presence, or an NBI for each TRP (e.g., a first TRP and a second TRP).

[0148] As shown in the sixth operation 830, the network node 110 may send an RRC connection establishment message. The RRC connection establishment message may be referred to as message 4, msg4, MSG4, or a fourth message of the four-step random access procedure. In some aspects, the RRC connection establishment message may include a detected UE identifier, a timing advance value, or contention resolution information. As shown in the seventh operation 835, if the UE 120 successfully receives the RRC connection establishment message, the UE 120 may send a HARQ ACK.

[0149] Fig. 9 is a diagram illustrating an example 900 of a four-step random access procedure according to the present disclosure. Fig. 9 As shown, the network node 110 and the UE 120 may communicate with each other to perform a four-step random access procedure.

[0150] As shown in a first operation 905, the UE 120 may identify a new candidate beam for the first NBI-RS set and a new candidate beam for the second NBI-RS set before sending a first random access message.

[0151] As shown in the second operation 910, the UE may select an SSB among the new candidate beams. In some aspects, the new candidate beam is associated with an SSB having an RSRP that satisfies an RSRP threshold (e.g., rsrp-ThresholdSSB), and the SSB associated with the new candidate beam may have a higher RSRP than SSBs outside the new candidate beam. In some aspects, the TAC in the RAR corresponds to a TAG associated with the first NBI-RS set or the second NBI-RS set to which the selected SSB belongs. In some aspects, the TAG may be associated with the NBI-RS set based at least in part on, for example, one or more bases described herein.

[0152] As shown in the third operation 915, the UE 120 may send a RAM, which may include a preamble (sometimes referred to as a random access preamble, a PRACH preamble, or a RAM preamble). The message including the preamble may be referred to as message 1, msg1, MSG1, a first message, or an initial message in the four-step random access process. The random access message may include a random access preamble identifier.

[0153] As shown in the fourth operation 920, the network node 110 may send a RAR as a response to the preamble. The message including the RAR may be referred to as message 2, msg2, MSG2, or a second message in the four-step random access procedure. In some aspects, the RAR may indicate a detected random access preamble identifier (e.g., received from the UE 120 in msg1). Additionally or alternatively, the RAR may indicate a resource allocation to be used by the UE 120 to send message 3 (msg3).

[0154] In some aspects, as part of the second step of the four-step random access procedure, the network node 110 may send a PDCCH communication for the RAR. The PDCCH communication may schedule a PDSCH communication including the RAR. For example, the PDCCH communication may indicate a resource allocation for the PDSCH communication. Also as part of the second step of the four-step random access procedure, the network node 110 may send a PDSCH communication for the RAR as scheduled by the PDCCH communication. The RAR may be included in the MAC PDU of the PDSCH communication. The RAR may include an indication of the TAC for subsequent communications.

[0155] As shown in the fifth operation 925, UE 120 may send an RRC connection request message. The RRC connection request message may be referred to as message 3, msg3, MSG3, or the third message of the four-step random access procedure. In some aspects, the RRC connection request may include a UE identifier, a UCI, or a PUSCH communication (e.g., an RRC connection request). The RRC connection request may include an index of a component carrier that includes a failed TRP link. In some examples, the RRC connection request may indicate a failed BFR set identifier, an NBI presence, or an NBI for each TRP (e.g., a first TRP and a second TRP).

[0156] As shown in the sixth operation 930, the network node 110 may send an RRC connection establishment message. The RRC connection establishment message may be referred to as message 4, msg4, MSG4, or the fourth message of the four-step random access procedure. In some aspects, the RRC connection establishment message may include a detected UE identifier, a timing advance value, or contention resolution information. As shown in the seventh operation 935, if the UE 120 successfully receives the RRC connection establishment message, the UE 120 may send a HARQ ACK.

[0157] Fig.10 1 is a diagram illustrating an example 1000 of a four-step random access procedure according to the present disclosure. Fig.10 As shown, the network node 110 and the UE 120 may communicate with each other to perform a four-step random access procedure.

[0158] As shown in the first operation 1005, the UE 120 may trigger a BFR procedure for a first BFD-RS set. For example, the UE may trigger a CBRA and may trigger a BFR procedure for one BFD-RS set of the serving cell. In this case, the TAC in the RAR may correspond to a TAG associated with a non-faulty BFD-RS set. For example, the UE may trigger a BFR procedure for a second radio link associated with a second TAG. In this case, the TAC may be applied to a first TAG associated with a first radio link for which the BFR procedure was not triggered.

[0159] In some aspects, the association between the TAG and the BFD-RS set can be determined based on the association between the TAG and the NBI-RS set and the association between the BFD-RS set and the NBI-RS set. In some aspects, the association between the TAG and the BFD-RS set can be defined at least in part based on a rule or configuration. In some aspects, the first TAG can be associated with the first BFD-RS set based at least in part on a CORESET pool index (e.g., a CORESETPoolIndex value). For example, the first TAG can be associated with the first BFD-RS set based at least in part on the first TAG and the first BFD-RS being associated with the first CORESET pool index value (e.g., CORESETPoolIndex_0) or the second TAG and the second BFD-RS being associated with the second CORESET pool index value (e.g., CORESETPoolIndex_1).

[0160] For example, a first TAG may be associated with a first BFD-RS set based at least in part on a rule. For example, based at least in part on a rule in a communication protocol or RRC configuration, a first TAG may be associated with a first BFD-RS set, and a second TAG may be associated with a second BFD-RS set. In some aspects, a TAG identifier may be configured for each BFD-RS set, or a TAG identifier may be configured for each RS in a BFD-RS set. For example, a BFD-RS set may be associated with a TAG ID that is associated with a RS in the BFD-RS set.

[0161] As shown in the second operation 1010, the UE 120 may send a RAM, which may include a preamble (sometimes referred to as a random access preamble, a PRACH preamble, or a RAM preamble). The message including the preamble may be referred to as message 1, msg1, MSG1, a first message, or an initial message in the four-step random access process. The random access message may include a random access preamble identifier.

[0162] As shown in the third operation 1015, the network node 110 may send a RAR as a response to the preamble. The message including the RAR may be referred to as message 2, msg2, MSG2, or a second message in the four-step random access procedure. In some aspects, the RAR may indicate a detected random access preamble identifier (e.g., received from the UE 120 in msg1). Additionally or alternatively, the RAR may indicate a resource allocation to be used by the UE 120 to send message 3 (msg3).

[0163] In some aspects, as part of the second step of the four-step random access procedure, the network node 110 may send a PDCCH communication for the RAR. The PDCCH communication may schedule a PDSCH communication including the RAR. For example, the PDCCH communication may indicate a resource allocation for the PDSCH communication. Also as part of the second step of the four-step random access procedure, the network node 110 may send a PDSCH communication for the RAR as scheduled by the PDCCH communication. The RAR may be included in the MAC PDU of the PDSCH communication. The RAR may include an indication of the TAC for subsequent communications.

[0164] As shown in the fourth operation 1020, UE 120 may send an RRC connection request message. The RRC connection request message may be referred to as message 3, msg3, MSG3, or the third message of the four-step random access procedure. In some aspects, the RRC connection request may include a UE identifier, a UCI, or a PUSCH communication (e.g., an RRC connection request). The RRC connection request may include an index of a component carrier that includes a failed TRP link. In some examples, the RRC connection request may indicate a failed BFR set identifier, an NBI presence, or an NBI for each TRP (e.g., a first TRP and a second TRP).

[0165] As shown in the fifth operation 1025, the network node 110 may send an RRC connection establishment message. The RRC connection establishment message may be referred to as message 4, msg4, MSG4, or a fourth message of the four-step random access procedure. In some aspects, the RRC connection establishment message may include a detected UE identifier, a timing advance value, or contention resolution information. As shown in the sixth operation 1030, if the UE 120 successfully receives the RRC connection establishment message, the UE 120 may send a HARQ ACK.

[0166] Fig.11 1 is a diagram illustrating an example 1100 of a four-step random access procedure according to the present disclosure. Fig.11 As shown, the network node 110 and the UE 120 may communicate with each other to perform a four-step random access procedure.

[0167] As shown in the first operation 1105, the UE 120 may select an SSB for the random access procedure. The UE may trigger the random access procedure based at least in part on a failure of the BFR procedure or an expiration of a time alignment timer, etc. In some aspects, the TAC in the RAR may correspond to the first TAG based at least in part on the first TAG being associated with the SSB selected for the random access procedure.

[0168] For example, the TAC in the RAR may correspond to the first TAG based at least in part on being associated with the same CORESET pool index as the selected SSB for the CBRA. In some aspects, the TAC in the RAR corresponds to the first TAG based at least in part on being associated with the selected SSB (e.g., if a TAG ID is associated or configured for each SSB).

[0169] As shown in the second operation 1110, the UE 120 may send a RAM, which may include a preamble (sometimes referred to as a random access preamble, a PRACH preamble, or a RAM preamble). The message including the preamble may be referred to as message 1, msg1, MSG1, a first message, or an initial message in the four-step random access process. The random access message may include a random access preamble identifier.

[0170] As shown in the third operation 1115, the network node 110 may send a RAR as a response to the preamble. The message including the RAR may be referred to as message 2, msg2, MSG2, or a second message in the four-step random access procedure. In some aspects, the RAR may indicate a detected random access preamble identifier (e.g., received from the UE 120 in msg1). Additionally or alternatively, the RAR may indicate a resource allocation to be used by the UE 120 to send message 3 (msg3).

[0171] In some aspects, as part of the second step of the four-step random access procedure, the network node 110 may send a PDCCH communication for the RAR. The PDCCH communication may schedule a PDSCH communication including the RAR. For example, the PDCCH communication may indicate a resource allocation for the PDSCH communication. Also as part of the second step of the four-step random access procedure, the network node 110 may send a PDSCH communication for the RAR as scheduled by the PDCCH communication. The RAR may be included in the MAC PDU of the PDSCH communication. The RAR may include an indication of the TAC for subsequent communications.

[0172] As shown in the fourth operation 1120, UE 120 may send an RRC connection request message. The RRC connection request message may be referred to as message 3, msg3, MSG3, or the third message of the four-step random access procedure. In some aspects, the RRC connection request may include a UE identifier, a UCI, or a PUSCH communication (e.g., an RRC connection request). The RRC connection request may include an index of a component carrier that includes a failed TRP link. In some examples, the RRC connection request may indicate a failed BFR set identifier, an NBI presence, or an NBI for each TRP (e.g., a first TRP and a second TRP).

[0173] As shown in the fifth operation 1125, the network node 110 may send an RRC connection establishment message. The RRC connection establishment message may be referred to as message 4, msg4, MSG4, or a fourth message of the four-step random access procedure. In some aspects, the RRC connection establishment message may include a detected UE identifier, a timing advance value, or contention resolution information. As shown in the sixth operation 1130, if the UE 120 successfully receives the RRC connection establishment message, the UE 120 may send a HARQ ACK.

[0174] Fig.12 1 is a flow chart illustrating an example process 1200 performed, for example, by a UE supporting selection of a TAG in a multi-TAG communication scheme in accordance with the present disclosure, in which the UE applies a TAC received during a random access procedure to the TAG. The example process 1200 is an example in which a UE (e.g., UE 120) performs operations associated with applying a TAC of an access channel message to one of a plurality of TAGs.

[0175] like Fig.12 As shown, in some aspects, process 1200 may include receiving an indication of a first TAG associated with a first radio link of a serving cell and a second TAG associated with a second radio link of the serving cell (block 1210). For example, a UE (such as by using Fig.13The communication manager 140 or receiving component 1302 depicted in FIG. 1 may receive an indication of a first TAG associated with a first radio link of a serving cell and a second TAG associated with a second radio link, as described above.

[0176] like Fig.12 As further shown, in some aspects, process 1200 may include sending a first random access channel (RACH) message on a serving cell based at least in part on a failure of a BFR process associated with at least one of a first BFD-RS set associated with a first radio link or a second BFD-RS set associated with a second radio link (block 1220). For example, a UE (such as by using Fig.13 The communication manager 140 or the sending component 1304 depicted in the figure may send a first random access channel (RACH) message on the serving cell based at least in part on a failure of a BFR process associated with at least one BFD-RS set from a first BFD-RS set associated with the first radio link or a second BFD-RS set associated with the second radio link, as described above.

[0177] like Fig.12 As further shown, in some aspects, process 1200 may include receiving a second RACH message indicating a TAC for a serving cell based at least in part on sending the first RACH message (block 1230). Fig.13 The communication manager 140 or receiving component 1302 depicted in FIG. 1 may receive a second RACH message indicating a TAC for a serving cell based at least in part on sending the first RACH message, as described above.

[0178] like Fig.12 As further shown, in some aspects, process 1200 may include communicating with a serving cell based at least in part on application of a TAC to a first TAG or a second TAG, application of the TAC to the first TAG or the second TAG being based at least in part on one or more of: whether a new candidate beam associated with the first radio link or the second radio link is identified prior to transmission of the first RACH message; a BFD-RS set in the first BFD-RS set or the second BFD-RS set that is not the at least one BFD-RS set for which a BFR process is not triggered; or an SSB associated with the first RACH message (block 1240). For example, a UE (such as by using Fig.13The communication manager 140, receiving component 1302 or sending component 1304 depicted in the figure may include communicating with the serving cell based at least in part on the application of the TAC to the first TAG or the second TAG, the application of the TAC to the first TAG or the second TAG being based at least in part on one or more of the following: whether a new candidate beam associated with the first wireless link or the second wireless link is identified prior to the transmission of the first RACH message; a BFD-RS set in the first BFD-RS set or the second BFD-RS set that is not the at least one BFD-RS set for which the BFR process is not triggered; or an SSB associated with the first RACH message, as described above.

[0179] Process 1200 may include additional aspects, such as any single aspect or any combination of aspects described below or in combination with one or more other processes described elsewhere herein.

[0180] In a first additional aspect, the first TAG is associated with a new beam identifier RS ​​(NBI-RS) set or a first BFD-RS set based at least in part on one or more of the following: at least one of the NBI-RS set or the first BFD-RS set and the first TAG are associated with the same CORESET pool index value; a mapping rule, or the first TAG is configured for the NBI-RS set or the first BFD-RS set.

[0181] In a second additional aspect, alone or in combination with the first aspect, the first TAG is configured for the first NBI-RS set or in the first BFD-RS set based at least in part on the configuration of the TAG identifier of the first TAG to the first NBI-RS set or the first BFD-RS set or to each RS in the first NBI-RS set or the first BFD-RS set.

[0182] In a third additional aspect, alone or in combination with one or more of the first and second aspects, process 1200 includes failing to identify a new candidate beam for any NBI-RS set prior to sending a first RACH message, wherein application of the TAC to the first TAG or the second TAG is based at least in part on whether the new candidate beam is identified prior to sending the first RACH message, and wherein application of the TAC to the first TAG is based at least in part on the first TAG being a default TAG.

[0183] In a fourth additional aspect, alone or in combination with one or more of the first to third aspects, the first TAG is a default TAG based at least in part on being associated with a first TAG associated with a first TAG index, a lowest TAG identity relative to a second TAG identity associated with a second TAG, or a default CORESET pool index.

[0184] In a fifth additional aspect, alone or in combination with one or more of the first to fourth aspects, process 1200 includes identifying a new candidate beam for an NBI-RS set prior to sending a first RACH message, wherein application of the TAC to the first TAG or the second TAG is based at least in part on whether the new candidate beam is identified prior to sending the first RACH message, and wherein the TAC is applied to the first TAG based at least in part on association of the first TAG with the NBI-RS set.

[0185] In a sixth additional aspect, alone or in combination with one or more of the first to fifth aspects, process 1200 includes identifying a first set of new candidate beams for a first NBI-RS set and a second set of new candidate beams for a second NBI-RS set before sending a first RACH message, and selecting an SSB associated with the first set of new candidate beams or the second set of new candidate beams, wherein application of the TAC to the first TAG or the second TAG is based at least in part on whether the new candidate beam is identified before sending the first RACH message, and wherein the TAC is applied to the first TAG based at least in part on the selected SSB being within the first set of candidate beams and the first TAG being associated with the first NBI-RS set.

[0186] In a seventh additional aspect, alone or in combination with one or more of the first to sixth aspects, the application of the TAC to the first TAG or the second TAG is based at least in part on a BFD-RS set in the first BFD-RS set or the second BFD-RS set that is not the at least one BFD-RS set for which the BFR process is not triggered, wherein at least one BFD-RS set is associated with the first TAG and a BFD-RS set that is not the at least one BFD-RS set is associated with the second TAG, and wherein the TAC is applied to the second TAG at least in part based on the association of the BFD-RS set with the second TAG.

[0187] In an eighth additional aspect, alone or in combination with one or more of the first to seventh aspects, the application of the TAC to the first TAG or the second TAG is based at least in part on an SSB associated with a first RACH message, wherein the SSB and the first TAG are associated with the same CORESET pool index, and wherein the TAC is applied to the first TAG based at least in part on the SSB and the first TAG being associated with the same CORESET pool index.

[0188] In a ninth additional aspect, either alone or in combination with one or more of aspects one to eight, the application of the TAC to the first TAG or the second TAG is based at least in part on an SSB associated with a first RACH message, wherein the first TAG is associated with the SSB, and wherein the TAC is applied to the first TAG based at least in part on the association of the first TAG with the SSB.

[0189] In a tenth additional aspect, alone or in combination with one or more of the first to ninth aspects, the first TAG is associated with communications with a first network node, and wherein the second TAG is associated with communications with a second network node.

[0190] In an eleventh additional aspect, alone or in combination with one or more of the first to tenth aspects, process 1200 includes identifying a beam failure for at least one BFD-RS set that triggers sending of a first RACH message.

[0191] Although Fig.12 An example block diagram of process 1200 is shown, but in some aspects, the same Fig.12 The process 1200 may include additional blocks, fewer blocks, different blocks, or differently arranged blocks than those depicted in FIG. Additionally or alternatively, two or more of the blocks of the process 1200 may be performed in parallel.

[0192] Fig.13 1 is a diagram of an example apparatus 1300 for wireless communication according to the present disclosure. Apparatus 1300 may be a UE, or a UE may include apparatus 1300. In some aspects, apparatus 1300 includes a receiving component 1302 and a transmitting component 1304 that may communicate with each other (e.g., via one or more buses or one or more other components). As shown, apparatus 1300 may communicate with another apparatus 1306 (such as a UE, a base station, or another wireless communication device) using receiving component 1302 and transmitting component 1304. As further shown, apparatus 1300 may include a communication manager (e.g., communication manager 140).

[0193] In some aspects, the apparatus 1300 may be configured to perform the Figures 6 to 11 Additionally or alternatively, the apparatus 1300 may be configured to perform one or more processes described herein, such as Fig.12 In some aspects, the apparatus 1300 or Fig.13 One or more of the components shown may include a combination of Figure 2 Additionally or alternatively, Fig.13 One or more of the components shown may be combined Figure 2Additionally or alternatively, one or more components in the set of components may be implemented at least in part as software stored in a memory. For example, a component (or a portion of a component) may be implemented as instructions or code stored in a non-transitory computer-readable medium and can be executed by a controller or processor to perform the function or operation of the component.

[0194] The receiving component 1302 may receive communications, such as reference signals, control information, data communications, or combinations thereof, from the apparatus 1306. The receiving component 1302 may provide the received communications to one or more other components of the apparatus 1300. In some aspects, the receiving component 1302 may perform signal processing (such as filtering, amplification, demodulation, analog-to-digital conversion, demultiplexing, deinterleaving, demapping, equalization, interference cancellation, or decoding, etc.) on the received communications and may provide the processed signals to one or more other components of the apparatus 1300. In some aspects, the receiving component 1302 may include combining Figure 2 One or more antennas, modems, demodulators, MIMO detectors, receive processors, controllers / processors, memories, or combinations thereof of a described UE.

[0195] The transmitting component 1304 may transmit communications, such as reference signals, control information, data communications, or combinations thereof, to the device 1306. In some aspects, one or more other components of the device 1300 may generate communications and may provide the generated communications to the transmitting component 1304 for transmission to the device 1306. In some aspects, the transmitting component 1304 may perform signal processing (such as filtering, amplification, modulation, digital-to-analog conversion, multiplexing, interleaving, mapping, or encoding, etc.) on the generated communications and may transmit the processed signals to the device 1306. In some aspects, the transmitting component 1304 may include combining Figure 2 One or more antennas, modems, modulators, transmit MIMO processors, transmit processors, controllers / processors, memories, or combinations thereof of the described UE. In some aspects, the transmit component 1304 can be co-located with the receive component 1302 in a transceiver.

[0196] The receiving component 1302 may receive an indication of a first TAG associated with a first radio link of a serving cell and a second TAG associated with a second radio link of the serving cell. The sending component 1304 may send a first random access channel (RACH) message on the serving cell based at least in part on a failure of a BFR process associated with at least one of a first BFD-RS set associated with the first radio link or a second BFD-RS set associated with the second radio link. The receiving component 1302 may receive a second RACH message indicating a TAC for the serving cell based at least in part on sending the first RACH message. The receiving component 1302 or the sending component 1304 can communicate with the serving cell based at least in part on the application of the TAC to the first TAG or the second TAG, and the application of the TAC to the first TAG or the second TAG is based at least in part on one or more of the following: whether a new candidate beam associated with the first wireless link or the second wireless link is identified before the transmission of the first RACH message; a BFD-RS set in the first BFD-RS set or the second BFD-RS set that is not the at least one BFD-RS set and for which the BFR process is not triggered; or an SSB associated with the first RACH message.

[0197] The communications manager 1308 may fail to identify a new candidate beam for any NBI-RS set prior to sending a first RACH message, wherein application of the TAC to the first TAG or the second TAG is based at least in part on whether the new candidate beam is identified prior to sending the first RACH message, and wherein application of the TAC to the first TAG is based at least in part on the first TAG being a default TAG.

[0198] The communication manager 1308 may identify a new candidate beam for the NBI-RS set prior to sending a first RACH message, wherein application of the TAC to the first TAG or the second TAG is based at least in part on whether the new candidate beam is identified prior to sending the first RACH message, and wherein the TAC is applied to the first TAG based at least in part on associating the first TAG with the NBI-RS set.

[0199] The communication manager 1308 may identify a first set of new candidate beams for the first NBI-RS set and a second set of new candidate beams for the second NBI-RS set prior to sending the first RACH message.

[0200] The communication manager 1308 may select an SSB associated with a first set of new candidate beams or a second set of new candidate beams, wherein application of the TAC to the first TAG or the second TAG is based at least in part on whether the new candidate beam is identified prior to sending the first RACH message, and wherein the TAC is applied to the first TAG based at least in part on the selected SSB being within the first set of candidate beams and the first TAG being associated with the first NBI-RS set.

[0201] The communication manager 1308 may identify a beam failure for at least one BFD-RS set that triggers the transmission of the first RACH message.

[0202] Fig.13 The number and arrangement of components shown are provided as examples. Fig.13 There may be additional components, fewer components, different components, or differently arranged components than those shown. Fig.13 Two or more of the components shown may be implemented in a single component, or Fig.13 The single component shown may be implemented as multiple distributed components. Additionally or alternatively, Fig.13 The illustrated set (one or more) of components may perform the operations described as being performed by Fig.13 Another group of components shown performs one or more functions.

[0203] The following provides an overview of some aspects of the disclosure:

[0204] Aspect 1: A method of wireless communication performed by a user equipment (UE), the method comprising: receiving an indication of a first timing advance group (TAG) associated with a first radio link of a serving cell and a second TAG associated with a second radio link of the serving cell; sending a first random access channel (RACH) message on the serving cell based at least in part on a failure of a beam failure recovery (BFR) procedure associated with at least one of a first beam failure detection (BFD) reference signal (RS) set associated with the first radio link or a second BFD-RS set associated with the second radio link; receiving an indication of a forwarding request for the serving cell based at least in part on sending the first RACH message; a second RACH message of a timing advance command (TAC) for a zone; and communicating with the serving cell based at least in part on the application of the TAC to the first TAG or the second TAG, the application of the TAC to the first TAG or the second TAG being based at least in part on one or more of: whether a new candidate beam associated with the first radio link or the second radio link is identified before the sending of the first RACH message; a BFD-RS set in the first BFD-RS set or the second BFD-RS set that is not the at least one BFD-RS set for which the BFR process is not triggered; or a synchronization signal block (SSB) associated with the first RACH message.

[0205] Aspect 2: A method according to Aspect 1, wherein the first TAG is associated with a new beam identifier RS ​​(NBI-RS) set or the first BFD-RS set based at least in part on one or more of the following: at least one of the NBI-RS set or the first BFD-RS set and the first TAG are associated with the same control resource set (CORESET) pool index value; a mapping rule; or the first TAG is configured for the NBI-RS set or the first BFD-RS set.

[0206] Aspect 3: A method according to Aspect 2, wherein the first TAG is configured for the first NBI-RS set or in the first BFD-RS set based at least in part on the TAG identifier of the first TAG to the following configuration: the first NBI-RS set or the first BFD-RS set, or each RS in the first NBI-RS set or the first BFD-RS set.

[0207] Aspect 4: According to the method described in any one of Aspects 1 to 3, the method also includes failing to identify the new candidate beam for any new beam identification RS (NBI-RS) set before the sending of the first RACH message, wherein the application of the TAC to the first TAG or the second TAG is at least partially based on whether the new candidate beam is identified before the sending of the first RACH message, and wherein the application of the TAC to the first TAG is at least partially based on the first TAG being a default TAG.

[0208] Aspect 5: A method according to Aspect 4, wherein the first TAG is a default TAG based at least in part on the first TAG being associated with: a first TAG associated with a first TAG index; a lowest TAG identity relative to a second TAG identity associated with the second TAG; or a default control resource set (CORESET) pool index.

[0209] Aspect 6: According to the method described in any one of Aspects 1 to 5, the method also includes identifying the new candidate beam for a new beam identification RS (NBI-RS) set before the sending of the first RACH message, wherein the application of the TAC to the first TAG or the second TAG is at least partially based on whether the new candidate beam is identified before the sending of the first RACH message, and wherein the TAC is applied to the first TAG at least partially based on the association of the first TAG with the NBI-RS set.

[0210] Aspect 7: According to the method described in any one of Aspects 1 to 6, the method further includes: identifying a first set of new candidate beams for a first new beam identification RS (NBI-RS) set and a second set of new candidate beams for a second NBI-RS set before sending the first RACH message; and selecting a synchronization signal block (SSB) associated with the first set of new candidate beams or the second set of new candidate beams, wherein the application of the TAC to the first TAG or the second TAG is at least partially based on whether the new candidate beam is identified before sending the first RACH message, and wherein the TAC is applied to the first TAG at least partially based on the selected SSB being within the first set of candidate beams and the first TAG being associated with the first NBI-RS set.

[0211] Aspect 8: A method according to any one of Aspects 1 to 7, wherein the application of the TAC to the first TAG or the second TAG is at least partially based on a BFD-RS set in the first BFD-RS set or the second BFD-RS set that is not the at least one BFD-RS set and for which the BFR process is not triggered, wherein the at least one BFD-RS set is associated with the first TAG, and the BFD-RS set that is not the at least one BFD-RS set is associated with the second TAG, and wherein the TAC is applied to the second TAG at least partially based on the association of the BFD-RS set with the second TAG.

[0212] Aspect 9: A method according to any one of Aspects 1 to 8, wherein the application of the TAC to the first TAG or the second TAG is based at least in part on the SSB associated with the first RACH message, wherein the SSB and the first TAG are associated with the same control resource set (CORESET) pool index, and wherein the TAC is applied to the first TAG based at least in part on the SSB and the first TAG being associated with the same CORESET pool index.

[0213] Aspect 10: A method according to any one of Aspects 1 to 9, wherein the application of the TAC to the first TAG or the second TAG is based at least in part on the SSB associated with the first RACH message, wherein the first TAG is associated with the SSB, and wherein the TAC is applied to the first TAG based at least in part on the association of the first TAG with the SSB.

[0214] Aspect 11: The method according to any one of aspects 1 to 10, wherein the first TAG is associated with communication with a first network node, and wherein the second TAG is associated with communication with a second network node.

[0215] Aspect 12: According to the method according to any one of Aspects 1 to 11, the method also includes identifying a beam failure for the at least one BFD-RS set that triggers the sending of the first RACH message.

[0216] Aspect 13: An apparatus for performing wireless communications at a device, the apparatus comprising: a processor; a memory coupled to the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform a method according to any one of Aspects 1 to 12.

[0217] Aspect 14: A device for wireless communication, the device comprising a memory and one or more processors coupled to the memory, the one or more processors configured to perform the method according to any one of aspects 1 to 12.

[0218] Aspect 15: An apparatus for wireless communication, the apparatus comprising at least one component for performing the method according to any one of aspects 1 to 12.

[0219] Aspect 16: A non-transitory computer-readable medium storing code for wireless communication, the code comprising instructions executable by a processor to perform the method according to any one of aspects 1 to 12.

[0220] Aspect 17: A non-transitory computer-readable medium storing an instruction set for wireless communication, the instruction set comprising one or more instructions that, when executed by one or more processors of a device, cause the device to perform a method according to any one of aspects 1 to 12.

[0221] The foregoing disclosure provides illustration and description, but is not intended to be exhaustive or to limit the aspects to the precise forms disclosed. Modifications and variations may be made in light of the above disclosure or may be acquired from practice of the various aspects.

[0222] As used herein, the term "component" is intended to be broadly interpreted as a combination of hardware or hardware and software. "Software" should be broadly interpreted as meaning an instruction, an instruction set, a code, a code segment, a program code, a program, a subroutine, a software module, an application, a software application, a software package, a routine, a subroutine, an object, an executable program, a thread of execution, a process, or a function, etc., whether it is described in software, firmware, middleware, microcode, hardware description language or other terms. As used herein, a "processor" is implemented with a combination of hardware or hardware and software. It will be obvious that the system or method described herein can be implemented in different forms of hardware or a combination of hardware and software. The actual dedicated control hardware or software code for implementing these systems or methods does not limit various aspects. Therefore, the operation and behavior of these systems or methods are described herein without reference to specific software codes, because those skilled in the art will understand that software and hardware can be designed to implement these systems or methods based at least in part on the description herein.

[0223] As used herein, "satisfying a threshold" may refer to a value being greater than a threshold, greater than or equal to a threshold, less than a threshold, less than or equal to a threshold, equal to a threshold, not equal to a threshold, etc., depending on the context.

[0224] Although the specific combination of features is stated in the claims or disclosed in the specification, these combinations are not intended to limit the disclosure of various aspects. Many of these features can be combined in a manner not specifically described in the claims or not disclosed in the specification. The disclosure of various aspects includes each dependent claim combined with each other claim in the claim set. As used herein, the phrase "at least one of" the list of items refers to any combination of these items (which includes a single member). As an example, "at least one of the following: a, b or c" is intended to cover a, b, c, a+b, a+c, b+c and a+b+c, and any combination with multiple identical elements (for example, a+a, a+a+a, a+a+b, a+a+c, a+b+b, a+c+c, b+b, b+b+b, b+b+c, c+c and c+c+c, or any other ordering of a, b and c).

[0225] Any element, action or instruction used herein should not be interpreted as key or necessary unless explicitly described as such. In addition, as used herein, the article "one" is intended to include one or more items, and can be used interchangeably with "one or more". In addition, as used herein, the article "said" is intended to include one or more items connected to the article "said", and can be used interchangeably with "one or more". In addition, as used herein, the terms "set" and "group" are intended to include one or more items, and can be used interchangeably with "one or more". If only one item is intended to be referred to, the phrase "only one" or similar terms will be used. Moreover, as used herein, the term "having" and similar terms are intended to be open terms, which do not limit the elements they modify (for example, "having" A elements can also have B). In addition, the phrase "based on" is intended to represent "based at least in part on", unless explicitly stated otherwise. Furthermore, as used herein, the term "or" when used consecutively is intended to be inclusive and used interchangeably with "and / or" unless explicitly stated otherwise (e.g., if used in conjunction with "either one of" or "only one of").

Claims

1. A user equipment (UE) for wireless communication, the user equipment (UE) comprising: Memory; as well as one or more processors coupled to the memory, the one or more processors configured to: receiving an indication of a first timing advance group (TAG) associated with a first radio link of a serving cell and a second TAG associated with a second radio link of the serving cell; transmitting a first random access channel (RACH) message on the serving cell based at least in part on a failure of a beam failure recovery (BFR) procedure associated with at least one of a first beam failure detection (BFD) reference signal (RS) set associated with the first radio link or a second BFD-RS set associated with the second radio link; receiving a second RACH message indicating a timing advance command (TAC) for the serving cell based at least in part on sending the first RACH message; as well as communicating with the serving cell based at least in part on applying the TAC to the first TAG or the second TAG, the applying of the TAC to the first TAG or the second TAG based at least in part on one or more of: whether a new candidate beam associated with the first radio link or the second radio link is identified prior to said sending of the first RACH message, a BFD-RS set in the first BFD-RS set or the second BFD-RS set that is not the at least one BFD-RS set and for which the BFR process is not triggered, or A synchronization signal block (SSB) associated with the first RACH message.

2. The UE of claim 1 , wherein the first TAG is associated with a new beam identifier RS ​​(NBI-RS) set or the first BFD-RS set based at least in part on one or more of: At least one of the NBI-RS set or the first BFD-RS set and the first TAG are associated with the same control resource set (CORESET) pool index value, mapping rules, or The first TAG is configured for the NBI-RS set or the first BFD-RS set.

3. The UE of claim 2, wherein the first TAG is configured for the first NBI-RS set or configured in the first BFD-RS set based at least in part on a TAG identifier of the first TAG to the following configuration: the first NBI-RS set or the first BFD-RS set, or Each RS in the first NBI-RS set or the first BFD-RS set.

4. The UE of claim 1 , wherein the one or more processors are further configured to, prior to the sending of the first RACH message, fail to identify the new candidate beam for any new beam identification RS (NBI-RS) set, wherein said applying of said TAC to said first TAG or said second TAG is based at least in part on whether said new candidate beam is identified prior to said sending of said first RACH message, and Wherein the applying of the TAC to the first TAG is based at least in part on the first TAG being a default TAG.

5. The UE of claim 4, wherein the first TAG is a default TAG based at least in part on being associated with: the first TAG associated with the first TAG index, the lowest TAG identity relative to the second TAG identity associated with the second TAG, or Default control resource set (CORESET) pool index.

6. The UE of claim 1, wherein the one or more processors are further configured to identify the new candidate beam for a new beam identification RS (NBI-RS) set prior to the sending of the first RACH message, wherein said applying of said TAC to said first TAG or said second TAG is based at least in part on whether said new candidate beam is identified prior to said sending of said first RACH message, and The TAC is applied to the first TAG based at least in part on associating the first TAG with the NBI-RS set.

7. The UE of claim 1, wherein the one or more processors are further configured to: identifying, prior to said sending of said first RACH message, a first set of new candidate beams for a first New Beam Identification RS (NBI-RS) set and a second set of new candidate beams for a second NBI-RS set; and selecting a synchronization signal block (SSB) associated with the first set of new candidate beams or the second set of new candidate beams, wherein the application of the TAC to the first TAG or the second TAG is based at least in part on whether the new candidate beam is identified prior to sending the first RACH message, and The TAC is applied to the first TAG based at least in part on the selected SSB being within the first set of candidate beams and the first TAG being associated with the first NBI-RS set.

8. The UE of claim 1 , wherein the application of the TAC to the first TAG or the second TAG is based at least in part on a BFD-RS set in the first BFD-RS set or the second BFD-RS set that is not the at least one BFD-RS set and for which the BFR process is not triggered, wherein the at least one BFD-RS set is associated with the first TAG, and the BFD-RS set that is not the at least one BFD-RS set is associated with the second TAG, and The TAC is applied to the second TAG based at least in part on associating the BFD-RS set with the second TAG.

9. The UE of claim 1 , wherein the application of the TAC to the first TAG or the second TAG is based at least in part on the SSB associated with the first RACH message, wherein the SSB and the first TAG are associated with the same control resource set (CORESET) pool index, and Wherein the TAC is applied to the first TAG based at least in part on the SSB and the first TAG being associated with the same CORESET pool index.

10. The UE of claim 1 , wherein the application of the TAC to the first TAG or the second TAG is based at least in part on the SSB associated with the first RACH message, wherein the first TAG is associated with the SSB, and Wherein the TAC is applied to the first TAG based at least in part on associating the first TAG with the SSB.

11. The UE of claim 1, wherein the first TAG is associated with communications with a first network node, and wherein the second TAG is associated with communications with a second network node.

12. The UE of claim 1, wherein the one or more processors are further configured to identify a beam failure for the at least one BFD-RS set that triggers the sending of the first RACH message.

13. A method of wireless communication performed by a user equipment (UE), the method comprising: receiving an indication of a first timing advance group (TAG) associated with a first radio link of a serving cell and a second TAG associated with a second radio link of the serving cell; transmitting a first random access channel (RACH) message on the serving cell based at least in part on a failure of a beam failure recovery (BFR) procedure associated with at least one of a first beam failure detection (BFD) reference signal (RS) set associated with the first radio link or a second BFD-RS set associated with the second radio link; receiving a second RACH message indicating a timing advance command (TAC) for the serving cell based at least in part on sending the first RACH message; as well as communicating with the serving cell based at least in part on applying the TAC to the first TAG or the second TAG, the applying of the TAC to the first TAG or the second TAG based at least in part on one or more of: whether a new candidate beam associated with the first radio link or the second radio link is identified prior to said sending of the first RACH message, a BFD-RS set in the first BFD-RS set or the second BFD-RS set that is not the at least one BFD-RS set and for which the BFR process is not triggered, or A synchronization signal block (SSB) associated with the first RACH message.

14. The method of claim 13, wherein the first TAG is associated with a new beam identifier RS ​​(NBI-RS) set or the first BFD-RS set based at least in part on one or more of: At least one of the NBI-RS set or the first BFD-RS set and the first TAG are associated with the same control resource set (CORESET) pool index value, mapping rules, or The first TAG is configured for the NBI-RS set or the first BFD-RS set.

15. The method of claim 14, wherein the first TAG is configured for the first NBI-RS set or configured in the first BFD-RS set based at least in part on a TAG identifier of the first TAG to: the first NBI-RS set or the first BFD-RS set, or Each RS in the first NBI-RS set or the first BFD-RS set.

16. The method of claim 13, further comprising failing to identify the new candidate beam for any new beam identification RS (NBI-RS) set prior to the sending of the first RACH message, wherein said applying of said TAC to said first TAG or said second TAG is based at least in part on whether said new candidate beam is identified prior to said sending of said first RACH message, and Wherein the applying of the TAC to the first TAG is based at least in part on the first TAG being a default TAG.

17. The method of claim 16, wherein the first TAG is a default TAG based at least in part on the first TAG being associated with: the first TAG associated with the first TAG index, the lowest TAG identity relative to the second TAG identity associated with the second TAG, or Default control resource set (CORESET) pool index.

18. The method of claim 13, further comprising identifying the new candidate beam for a new beam identification RS (NBI-RS) set prior to the sending of the first RACH message, wherein said applying of said TAC to said first TAG or said second TAG is based at least in part on whether said new candidate beam is identified prior to said sending of said first RACH message, and The TAC is applied to the first TAG based at least in part on associating the first TAG with the NBI-RS set.

19. The method according to claim 13, further comprising: identifying, prior to said sending of said first RACH message, a first set of new candidate beams for a first New Beam Identification RS (NBI-RS) set and a second set of new candidate beams for a second NBI-RS set; as well as selecting a synchronization signal block (SSB) associated with the first set of new candidate beams or the second set of new candidate beams, wherein the application of the TAC to the first TAG or the second TAG is based at least in part on whether the new candidate beam is identified prior to sending the first RACH message, and The TAC is applied to the first TAG based at least in part on the selected SSB being within the first set of candidate beams and the first TAG being associated with the first NBI-RS set.

20. The method of claim 13, wherein the applying of the TAC to the first TAG or the second TAG is based at least in part on a BFD-RS set in the first BFD-RS set or the second BFD-RS set that is not the at least one BFD-RS set for which the BFR process is not triggered, wherein the at least one BFD-RS set is associated with the first TAG, and the BFD-RS set that is not the at least one BFD-RS set is associated with the second TAG, and The TAC is applied to the second TAG based at least in part on associating the BFD-RS set with the second TAG.

21. The method of claim 13, wherein the application of the TAC to the first TAG or the second TAG is based at least in part on the SSB associated with the first RACH message, wherein the SSB and the first TAG are associated with the same control resource set (CORESET) pool index, and Wherein the TAC is applied to the first TAG based at least in part on the SSB and the first TAG being associated with the same CORESET pool index.

22. The method of claim 13, wherein the application of the TAC to the first TAG or the second TAG is based at least in part on the SSB associated with the first RACH message, wherein the first TAG is associated with the SSB, and Wherein the TAC is applied to the first TAG based at least in part on associating the first TAG with the SSB.

23. The method of claim 13, wherein the first TAG is associated with communications with a first network node, and wherein the second TAG is associated with communications with a second network node.

24. The method of claim 13, further comprising identifying a beam failure for the at least one BFD-RS set that triggers the sending of the first RACH message.

25. A non-transitory computer readable medium storing an instruction set for wireless communication, the instruction set comprising: One or more instructions that, when executed by one or more processors of a user equipment (UE), cause the UE to: receiving an indication of a first timing advance group (TAG) associated with a first radio link of a serving cell and a second TAG associated with a second radio link of the serving cell; transmitting a first random access channel (RACH) message on the serving cell based at least in part on a failure of a beam failure recovery (BFR) procedure associated with at least one of a first beam failure detection (BFD) reference signal (RS) set associated with the first radio link or a second BFD-RS set associated with the second radio link; receiving a second RACH message indicating a timing advance command (TAC) for the serving cell based at least in part on sending the first RACH message; as well as communicating with the serving cell based at least in part on applying the TAC to the first TAG or the second TAG, the applying of the TAC to the first TAG or the second TAG based at least in part on one or more of: whether a new candidate beam associated with the first radio link or the second radio link is identified prior to said sending of the first RACH message, a BFD-RS set in the first BFD-RS set or the second BFD-RS set that is not the at least one BFD-RS set and for which the BFR process is not triggered, or A synchronization signal block (SSB) associated with the first RACH message.

26. The non-transitory computer-readable medium of claim 25, wherein the first TAG is associated with a new beam identification RS (NBI-RS) set or the first BFD-RS set based at least in part on one or more of: At least one of the NBI-RS set or the first BFD-RS set and the first TAG are associated with the same control resource set (CORESET) pool index value, mapping rules, or The first TAG is configured for the NBI-RS set or the first BFD-RS set.

27. The non-transitory computer-readable medium of claim 26, wherein the first TAG is configured for the first NBI-RS set or configured in the first BFD-RS set based at least in part on a TAG identification of the first TAG to: the first NBI-RS set or the first BFD-RS set, or Each RS in the first NBI-RS set or the first BFD-RS set.

28. An apparatus for wireless communication, the apparatus comprising: means for receiving an indication of a first timing advance group (TAG) associated with a first radio link of a serving cell and a second TAG associated with a second radio link of the serving cell; means for transmitting a first random access channel (RACH) message on the serving cell based at least in part on a failure of a beam failure recovery (BFR) procedure associated with at least one of a first beam failure detection (BFD) reference signal (RS) set associated with the first radio link or a second BFD-RS set associated with the second radio link; means for receiving a second RACH message indicating a timing advance command (TAC) for the serving cell based at least in part on sending the first RACH message; as well as means for communicating with the serving cell based at least in part on application of the TAC to the first TAG or the second TAG, the application of the TAC to the first TAG or the second TAG being based at least in part on one or more of: whether a new candidate beam associated with the first radio link or the second radio link is identified prior to said sending of the first RACH message, a BFD-RS set in the first BFD-RS set or the second BFD-RS set that is not the at least one BFD-RS set and for which the BFR process is not triggered, or A synchronization signal block (SSB) associated with the first RACH message.

29. The apparatus of claim 28, wherein the first TAG is associated with a new beam identifier RS ​​(NBI-RS) set or the first BFD-RS set based at least in part on one or more of: At least one of the NBI-RS set or the first BFD-RS set and the first TAG are associated with the same control resource set (CORESET) pool index value, mapping rules, or The first TAG is configured for the NBI-RS set or the first BFD-RS set.

30. The apparatus of claim 29, wherein the first TAG is configured for the first NBI-RS set or configured in the first BFD-RS set based at least in part on a TAG identifier of the first TAG to: the first NBI-RS set or the first BFD-RS set, or Each RS in the first NBI-RS set or the first BFD-RS set.

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