User Equipment (UE) Capability of Secondary Cell (SCELL) Beam Failure Recovery (BFR)

Abstract

Various aspects of the present disclosure relate to wireless communications, and more particularly, various aspects of the present disclosure relate to techniques for wireless communications by a user equipment (UE). Embodiments include reporting to a network entity the capability of the UE to support beam failure recovery (BFR) on one or more secondary cells (SCells). Embodiments include detecting a beam failure of a beam pair link (BPL) associated with a Scell ​​in one or more SCells. Embodiments include, in response to the detection, performing BFR according to the reported capability.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of priority to U.S. Application No. 17 / 168,470, filed on February 5, 2021, which claims the benefit of U.S. Provisional Patent Application No. 62 / 971,035, filed on February 6, 2020, the entire contents of which are expressly incorporated herein by reference, as if fully set forth below. Technical Field

[0003]

[0004] Generally speaking, aspects of the present disclosure relate to wireless communications, and more particularly, to techniques for signaling user equipment (UE) capabilities for secondary cell (SCell) beam failure recovery (BFR). Background Art

[0004] Wireless communication systems are widely deployed to provide a variety of telecommunication services such as telephony, video, data, messaging, broadcasts, and the like. These wireless communication systems may employ multiple access technologies that can support communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power, and the like). Examples of such multiple access systems include third generation partnership project (3GPP) long term evolution (LTE) systems, LTE-Advanced (LTE-A) systems, 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, and time division synchronous code division multiple access (TD-SCDMA) systems, to name a few.

[0005] In some examples, a wireless multiple access communication system may include multiple base stations (BSs), each of which is capable of simultaneously supporting communication of multiple communication devices (or user equipment (UE)). In an LTE or LTE-A network, a group of one or more base stations may define an eNodeB (eNB). In other examples (e.g., in a next generation, new radio (NR) or 5G network), a wireless multiple access communication system may include multiple distributed units (DUs) (e.g., edge units (EUs), edge nodes (ENs), radio heads (RHs), smart radio heads (SRHs), transmission reception points (TRPs), etc.) communicating with multiple central units (CUs) (e.g., central nodes (CNs), access node controllers (ANCs), etc.), wherein a group of one or more distributed units communicating with a central unit may define an access node (e.g., which may be referred to as a base station, a 5G NB, a next generation Node B (gNB or gNodeB), a TRP, etc.). A base station or distributed unit may communicate with a group of UEs on downlink channels (eg, for transmissions from the base station or central unit to the UEs) and uplink channels (eg, for transmissions from the UEs to the base station or distributed unit).

[0006] These multiple access technologies have been adopted in a variety of telecommunication standards to provide a common protocol that enables different wireless devices to communicate on a city-wide, national-wide, regional-wide, and even global scale. New Radio (NR) (e.g., 5G) is an example of an emerging telecommunication standard. NR is an evolution of the LTE mobile standard released by 3GPP. NR is designed to better support mobile broadband Internet access by improving spectrum efficiency, reducing costs, improving services, making full use of new spectrum, and better integrating with other open standards using OFDMA and cyclic prefix (CP) on downlink (DL) and uplink (UL). To this end, NR supports beamforming, multiple-input multiple-output (MIMO) antenna technology, and carrier aggregation.

[0007] However, as the demand for mobile broadband access continues to increase, there is a need to further improve NR and LTE technologies. Preferably, these improvements can also be applied to other multiple access technologies and communication standards that adopt these technologies. Summary of the invention

[0008] The systems, methods, and devices of the present disclosure each have aspects, no single one of which is solely responsible for its desirable attributes. The claims set forth below do not limit the scope of the present disclosure, and some features will now be briefly discussed. After carefully considering this discussion, and particularly after reading the section entitled "Detailed Description of the Invention," one will understand how the features of the present disclosure provide advantages, including improved communications between access points and stations in a wireless network.

[0009] Certain aspects provide a method for wireless communications performed by a user equipment (UE). In general, the method includes: reporting to a network entity the capability of the UE to support beam failure recovery (BFR) on one or more secondary cells (SCells). The method also includes: detecting a beam failure of a beam pair link (BPL) associated with a Scell ​​in the one or more SCells. The method also includes: in response to the detection, performing BFR according to the reported capability.

[0010] Certain aspects of the present disclosure provide a method for wireless communications of a network entity. In general, the method includes: receiving from a user equipment (UE) an indication of the UE's ability to support beam failure recovery (BFR) on one or more secondary cells (SCells). The method also includes: receiving from the UE an indication of a detected beam failure of a beam pair link (BPL) associated with an Scell ​​in the one or more SCells. The method also includes: in response to receiving the indication of the detected beam failure, taking action according to the reported capability to initiate BFR.

[0011] Certain aspects provide an apparatus for wireless communication of a user equipment (UE). The apparatus may include a memory and a processor coupled to the memory. The memory and the processor may be configured to report to a network entity the ability of the UE to support beam failure recovery (BFR) on one or more secondary cells (SCells). The memory and the processor may be further configured to: detect a beam failure of a beam pair link (BPL) associated with an Scell ​​in the one or more SCells. The memory and the processor may be further configured to: in response to the detection, perform BFR according to the reported capability.

[0012] Certain aspects provide an apparatus for wireless communication of a network entity. The apparatus may include a memory and a processor coupled to the memory. The memory and processor may be configured to receive from a user equipment (UE) an indication of the UE's ability to support beam failure recovery (BFR) on one or more secondary cells (SCells). The memory and processor may be further configured to: receive from the UE an indication of a detected beam failure of a beam pair link (BPL) associated with an Scell ​​in the one or more SCells. The memory and processor may be further configured to: in response to receiving an indication of the detected beam failure, take action according to the reported capability to initiate BFR.

[0013] Certain aspects provide an apparatus for wireless communication performed by a user equipment (UE). The apparatus generally includes: a unit for reporting to a network entity the capability of the UE to support beam failure recovery (BFR) on one or more secondary cells (SCells). The apparatus also includes: a unit for detecting a beam failure of a beam pair link (BPL) associated with a Scell ​​in the one or more SCells. The apparatus also includes: a unit for performing BFR according to the reported capability in response to the detection.

[0014] Certain aspects provide an apparatus for wireless communications performed by a network entity. The apparatus generally includes: a unit for receiving from a user equipment (UE) an indication of the UE's ability to support beam failure recovery (BFR) on one or more secondary cells (SCells). The apparatus also includes: a unit for receiving from the UE an indication of a detected beam failure of a beam pair link (BPL) associated with an Scell ​​in the one or more SCells. The apparatus also includes: a unit for taking action to initiate BFR based on the reported capability in response to receiving an indication of the detected beam failure.

[0015] Certain aspects may be implemented using a non-transitory computer-readable medium for wireless communication of a user equipment (UE). The non-transitory computer-readable medium may include computer-executable instructions that, when executed by one or more processors of a processing system, cause the processing system to report to a network entity the ability of the UE to support beam failure recovery (BFR) on one or more secondary cells (SCells). When the computer-executable instructions are executed by the one or more processors of the processing system, the processing system is further caused to detect a beam failure of a beam pair link (BPL) associated with an Scell ​​in the one or more SCells. When the computer-executable instructions are executed by the one or more processors of the processing system, the processing system is further caused to perform BFR in response to the detection based on the reported capability.

[0016] Certain aspects may be implemented using a non-transitory computer-readable medium for wireless communication of a user equipment (UE). The non-transitory computer-readable medium may include computer-executable instructions that, when executed by one or more processors of a processing system, cause the processing system to receive from a user equipment (UE) an indication of the UE's ability to support beam failure recovery (BFR) on one or more secondary cells (SCells). When the computer-executable instructions are executed by the one or more processors of the processing system, further cause the processing system to receive from the UE an indication of a detected beam failure of a beam pair link (BPL) associated with an Scell ​​in the one or more SCells. When the computer-executable instructions are executed by the one or more processors of the processing system, further cause the processing system to take action to initiate BFR in response to receiving an indication of the detected beam failure based on the reported capability.

[0017] Aspects of the present disclosure provide units, devices, processors and computer-readable media for performing the methods described herein.

[0018] To achieve the aforementioned and related purposes, one or more aspects include the features described in detail below and specifically pointed out in the claims. The following description and the accompanying drawings describe in detail certain exemplary features of one or more aspects. However, these features are only illustrative of some of the various ways in which the basic principles of these various aspects can be employed.

[0019] In order to better understand the following specific embodiments, the features and technical advantages of the examples according to the present disclosure have been generally summarized to a considerable extent. Additional features and advantages will be described below. The disclosed concepts and specific examples can be easily used as the basis for modifying or designing other structures for the same purpose of performing the present disclosure. These equivalent constructions do not depart from the scope of protection of the attached claims. When considering the following specific embodiments in conjunction with the accompanying drawings, the characteristics of the concepts disclosed herein (about their organization and method of operation), and the associated advantages will be better understood. Each of these drawings is provided for illustration and description purposes only, and is not used as a limitation to the present invention.

[0020] Although various aspects and embodiments are described in this application by describing some examples, it should be understood by those of ordinary skill in the art that other implementations and use cases can be implemented in many different arrangements and scenarios. The innovative methods described herein can be implemented using a variety of different platform types, devices, systems, shapes, sizes, and packaging arrangements. For example, embodiments and / or use cases can be implemented by integrated chip embodiments and other devices based on non-module components (e.g., end-user devices, vehicles, communication devices, computing devices, industrial equipment, retail / purchase equipment, medical devices, artificial intelligence devices, etc.). Although some examples may be specifically targeted at use cases or applications, they may not be specifically targeted at use cases or applications, but various applicability of the described innovations may occur. The scope of implementation can be from chip-level or modular components to non-modular, non-chip-level implementations, and can also be aggregated, distributed, or OEM devices or systems that include one or more aspects of the described innovations. In some actual settings, the device containing the described aspects and features may also have to include other components and features for implementing and practicing the claimed and described embodiments. For example, the transmission and reception of wireless signals must include multiple components for analog and digital purposes (e.g., hardware components including antennas, RF chains, power amplifiers, modulators, buffers, processors, interleavers, adders / accumulators, etc.). The innovations described herein can be practiced in a wide variety of devices, chip-level components, systems, distributed arrangements, end-user devices, etc., having different sizes, shapes, and configurations.

[0021] For purposes of illustration, the following description and drawings set forth certain features. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to understand in detail the implementation of the above-described features of the present disclosure, the present application provides a more specific description with reference to some aspects for the above brief summary, some of which are illustrated in the accompanying drawings. However, it should be noted that since the description of the present invention allows for other equally effective aspects, these drawings only depict some typical aspects of the present disclosure, which should not be considered to limit the scope of protection of the present invention.

[0023] Figure 1 is a block diagram conceptually illustrating an example telecommunications system in accordance with certain aspects of the present disclosure.

[0024] Figure 2 is a block diagram illustrating an example logical architecture of a distributed radio access network (RAN) in accordance with certain aspects of the present disclosure.

[0025] Figure 3 is a block diagram illustrating an exemplary physical architecture of a distributed RAN according to certain aspects of the present disclosure.

[0026] Figure 4 is a block diagram conceptually illustrating designs of example base stations (BSs) and user equipments (UEs) in accordance with certain aspects of the present disclosure.

[0027] Figure 5 is a diagram illustrating an example for implementing a communication protocol stack according to certain aspects of the present disclosure.

[0028] Figure 6 An example of a frame format for a New Radio (NR) system is shown.

[0029] Figure 7 According to certain aspects of the present disclosure, it is shown how different synchronization signal blocks (SSBs) may be sent using different beams.

[0030] Figure 8 According to certain aspects of the present disclosure, example transmission resource mappings are shown.

[0031] Fig. 9 An exemplary quasi-co-location (QCL) relationship is shown.

[0032] Fig.10 According to some aspects of the present disclosure, example operations for wireless communications of a user equipment (UE) are shown.

[0033] Fig.11 According to some aspects of the present disclosure, example operations for wireless communications of a network entity are shown.

[0034] Fig.12is a call flow diagram illustrating example operations for signaling UE capabilities of SCell BFR.

[0035] Fig.13 Example UE capability signaling for SCell BFR is shown.

[0036] Fig.14 According to aspects of the present disclosure, a communication device is shown that may include various components configured to perform operations of the techniques disclosed herein.

[0037] Fig.15 According to aspects of the present disclosure, a communication device is shown that may include various components configured to perform operations of the techniques disclosed herein.

[0038] To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It will be appreciated that elements disclosed in one aspect may be beneficially utilized in other aspects without specific recitation. DETAILED DESCRIPTION

[0039]

[0004] Generally speaking, aspects of the present disclosure relate to wireless communications, and more particularly, to techniques for signaling user equipment (UE) capabilities for secondary cell (SCell) beam failure recovery (BFR).

[0040] The following description provides some examples, but it does not limit the scope of protection, applicability or examples set forth in the claims. Without departing from the scope of protection of the present disclosure, the functions and arrangements of the components discussed can be changed. Various examples can omit, replace or add various processes or components as needed. For example, the described method can be performed in a different order than described, and various steps can be added, omitted or combined. In addition, the features described in some examples can be combined in other examples. For example, a device can be implemented or a method can be implemented using any number of aspects set forth herein. In addition, the scope of protection of the present disclosure is intended to cover such a device or method, which can be implemented by using other structures, functions, or structures and functions other than or different from the various aspects of the present disclosure set forth herein. It should be understood that any aspect of the disclosure disclosed herein can be embodied by one or more components of the present invention. The word "exemplary" used herein means "used as an example, illustration or description". Any aspect described as "exemplary" herein should not be interpreted as being more preferred or more advantageous than other aspects.

[0041] The technology described herein can be used for various wireless communication technologies, such as LTE, CDMA, TDMA, FDMA, OFDMA, SC-FDMA and other networks. The terms "network" and "system" are often used interchangeably. A CDMA network can implement radio technologies such as Universal Terrestrial Radio Access (UTRA), CDMA 2000, and the like. UTRA includes Wideband CDMA (WCDMA) and other variants of CDMA. CDMA 2000 covers IS-2000, IS-95, and IS-856 standards. A TDMA network can implement radio technologies such as Global System for Mobile Communications (GSM). An OFDMA network can implement radio technologies such as NR (e.g., 5G RA), Evolved UTRA (E-UTRA), Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE802.20, Flash-OFDMA, and the like. UTRA and E-UTRA are part of Universal Mobile Telecommunications System (UMTS).

[0042] New Radio (NR) is an emerging wireless communication technology deployed in conjunction with the 5G Technology Forum (5GTF). 3GPP Long Term Evolution (LTE) and Advanced LTE (LTE-A) are new releases of UMTS using E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A, and GSM are described in documents from an organization called "3rd Generation Partnership Project" (3GPP). CDMA2000 and UMB are described in documents from an organization called "3rd Generation Partnership Project 2" (3GPP2). The technology described herein can be used for the wireless networks and radio technologies mentioned above as well as other wireless networks and radio technologies. For the sake of clarity, although various aspects are described herein using terms commonly associated with 3G and / or 4G wireless technologies, various aspects of the present disclosure may also be applied to communication systems based on other generations (e.g., 5G and higher versions including NR technology).

[0043] New Radio (NR) access (e.g., 5G technology) can support various wireless communication services, such as enhanced mobile broadband (eMBB) targeting wider bandwidth (e.g., 80 MHz or above), millimeter wave (mmW) targeting high carrier frequency (e.g., 25 GHz or above), massive machine type communication MTC (mMTC) targeting non-backward compatible MTC technology, and / or mission critical ultra-reliable low latency communication (URLLC). These services may include latency and reliability requirements. These services may also have different transmission time intervals (TTIs) to meet corresponding quality of service (QoS) requirements. In addition, these services can coexist in the same subframe.

[0044] Exemplary Wireless Communication System

[0045] Figure 1 An exemplary wireless communication network 100 (e.g., an NR / 5G network) is shown in which aspects of the present disclosure may be performed. For example, the wireless communication network 100 may include a UE 120 configured to perform Fig.10 Operation 1000 of signaling a user equipment (UE) capability of secondary cell (SCell) beam failure recovery (BFR). Similarly, the base station 110 (e.g., gNB) may be configured to perform Fig.11 Operations 1100 of the system relate to signaling of UE capabilities for receiving SCell BFR.

[0046] like Figure 1 As shown in , the wireless network 100 may include multiple base stations (BS) 110 and other network entities. A BS may be a station that communicates with a user equipment (UE). Each BS 110 may provide communication coverage for a specific geographic area. In 3GPP, the term "cell" may refer to the coverage area of ​​a Node B (NB) and / or a Node B subsystem serving the coverage area, depending on the context in which the term "cell" is used. In the NR system, the term "cell" and the next generation Node B (gNB), new radio base station (NR BS), 5G NB, access point (AP) or transmission reception point (TRP) may be interchangeable. In some examples, the cell does not need to be stationary, and the geographical area of ​​the cell may move according to the location of the mobile BS. In some examples, the base station may be interconnected to each other and / or to one or more other base stations or network nodes (not shown) in the wireless communication network 100 using any appropriate transmission network through various types of backhaul interfaces (such as direct physical connections, wireless connections, virtual networks, etc.).

[0047] Typically, any number of wireless networks may be deployed in a given geographic area. Each wireless network may support a specific radio access technology (RAT) and may operate on one or more frequencies. RAT may also be referred to as radio technology, air interface, etc. Frequency may also be referred to as carrier, subcarrier, frequency channel, tone, subband, etc. 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.

[0048] A base station (BS) may provide communication coverage for macro cells, pico cells, femto cells, and / or other types of cells. A macro cell may cover a relatively large geographic area (e.g., a radius of several kilometers) and allow unrestricted access to UEs with service subscriptions. A pico cell may cover a relatively small geographic area and allow unrestricted access to UEs with service subscriptions. A femto cell may cover a relatively small geographic area (e.g., a home) and allow restricted access to UEs associated with the femto cell (e.g., UEs in a closed subscriber group (CSG), UEs for users in a home, etc.). A BS for a macro cell may be referred to as a macro BS. A BS for a pico cell may be referred to as a pico BS. A BS for a femto cell may be referred to as a femto BS or a home BS. In Figure 1 In the illustrated example, BS 110a, BS 110b, and BS 110c may be macro BSs for macro cell 102a, macro cell 102b, and macro cell 102c, respectively. BS 110x may be a pico BS for pico cell 102x. BS 110y and BS 110z may be femto BSs for femto cells 102y and 102z, respectively. A BS may support one or more (e.g., three) cells.

[0049] The wireless communication network 100 may also include a relay station. A relay station is a station that can receive transmissions of data and / or other information from an upstream station (e.g., a BS or a UE) and send transmissions of the data and / or other information to a downstream station (e.g., a UE or a BS). A relay station may also be a UE that can relay transmissions for other UEs. Figure 1 In the illustrated example, a relay station 110r may communicate with the BS 110a and the UE 120r to facilitate communication between the BS 110a and the UE 120r. A relay station may also be referred to as a relay BS, a relay, or the like.

[0050] The wireless network 100 may be a heterogeneous network including different types of BSs (e.g., macro BSs, pico BSs, femto BSs, relays, etc.). These different types of BSs may have different transmit power levels, different coverage areas, and different effects on interference in the wireless network 100. For example, a macro BS may have a higher transmit power level (e.g., 20 watts), while a pico BS, a femto BS, and a relay may have a lower transmit power level (e.g., 1 watt).

[0051] The wireless communication network 100 may support synchronous or asynchronous operation. For synchronous operation, the BSs may have similar frame timings, and transmissions from different BSs are approximately aligned in time. For asynchronous operation, the BSs may have different frame timings, and transmissions from different BSs are not aligned in time. The techniques described herein may be used for both synchronous and asynchronous operation.

[0052] The network controller 130 may be coupled to a group of BSs and provide coordination and control for these BSs. The network controller 130 may communicate with these BSs 110 via a backhaul. The BSs 110 may also communicate with each other (eg, directly or indirectly) via a wireless backhaul or a wired backhaul.

[0053] UEs 120 (eg, UE 120x, UE 120y, etc.) may be dispersed throughout wireless network 100, and each UE may be stationary or mobile. UE may also be referred to as a mobile station, a terminal, an access terminal, a subscriber unit, a station, customer premises equipment (CPE), a cellular phone, 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 computer, a camera, a gaming device, a netbook, a smartbook, an ultrabook, a home appliance, a medical device or medical apparatus, a biosensor / device, a wearable device such as a smart watch, smart clothing, smart glasses, a smart bracelet, smart jewelry (e.g., a smart bracelet, a smart bracelet, etc.), an entertainment device (e.g., a music device, a video device, a satellite radio device, etc.), a vehicle component or sensor, a smart meter / sensor, an industrial manufacturing equipment, a global positioning system device, a gaming device, an augmented reality device (augmented reality (AR), extended reality (XR), or virtual reality (VR)), or any other suitable device configured to communicate via a wireless or wired medium.

[0054] Some UEs may be considered as machine type communication (MTC) devices or evolved MTC (eMTC) devices. For example, MTC and eMTC UEs include robots, drones, remote devices, sensors, meters, monitors, location tags, etc. that can communicate with a BS, another device (e.g., a remote device), or some other entity. A wireless node may provide a connection for or to a network (e.g., a wide area network such as the Internet or a cellular network), for example, via a wired or wireless communication link. Some UEs may be considered as Internet of Things (IoT) devices, which may be narrowband IoT (NB-IoT) devices.

[0055] Some wireless networks (e.g., LTE) utilize orthogonal frequency division multiplexing (OFDM) on the downlink and single carrier frequency division multiplexing (SC-FDM) on the uplink. OFDM and SC-FDM divide the system bandwidth into multiple (K) orthogonal subcarriers, which are also commonly referred to as tones, frequencies, etc. Each subcarrier can be modulated with data. Typically, modulation symbols are sent in the frequency domain using OFDM and in the time domain using SC-FDM. The spacing between adjacent subcarriers can be fixed, and the total number of subcarriers (K) can depend on the system bandwidth. For example, the spacing of the subcarriers can be 15kHz, and the minimum resource allocation (which is called a "resource block" (RB)) can be 12 subcarriers (or 180kHz). Therefore, for system bandwidths of 1.25, 2.5, 5, 10, or 20 megahertz (MHz), the nominal fast Fourier transform (FFT) size can be equal to 128, 256, 512, 1024, or 2048, respectively. The system bandwidth may also be divided into several subbands. For example, one subband may cover 1.08 MHz (ie, 6 resource blocks), and there may be 1, 2, 4, 8 or 16 subbands for system bandwidths of 1.25, 2.5, 5, 10 or 20 MHz, respectively.

[0056] Although aspects of the examples described herein may be associated with LTE technology, aspects of the present disclosure may be applicable to other wireless communication systems (e.g., NR). NR may utilize OFDM with CP on the uplink and downlink, including support for half-duplex operation using TDD. Beamforming may be supported, and the beam direction may be dynamically configured. MIMO transmissions with precoding may also be supported. MIMO configurations in the DL may support up to 8 transmit antennas with multi-layer DL transmissions of up to 8 streams and up to 2 streams per UE. Multi-layer transmissions of up to 2 streams per UE may be supported. Aggregation of multiple cells of up to 8 serving cells may be supported.

[0057] In some scenarios, air interface access may be scheduled. For example, a scheduling entity (e.g., a base station (BS), Node B, eNB, gNB, etc.) may allocate resources for communications between some or all devices and equipment within its service area or cell. A scheduling entity may be responsible for scheduling, allocating, reconfiguring, and releasing resources for one or more subordinate entities. That is, for scheduled communications, subordinate entities may utilize resources allocated by one or more scheduling entities.

[0058] The base station is not the only entity that acts as a scheduling entity. In some examples, a UE can act as a scheduling entity and can schedule resources for one or more subordinate entities (e.g., one or more other UEs), and other UEs can use the resources scheduled by the UE for wireless communication. In some examples, a UE can act as a scheduling entity in a peer-to-peer (P2P) network and / or a mesh network. In the mesh network example, in addition to communicating with the scheduling entity, UEs can also communicate directly with each other.

[0059] Return to Figure 1 , which shows a wide variety of potential deployments for various deployment scenarios. For example, in Figure 1 , a solid line with double arrows represents a desired transmission between a UE and a serving BS, which is a BS designated to serve the UE on a downlink and / or uplink. A thin dashed line with double arrows indicates interfering transmissions between the UE and the BS. Other lines illustrate component-to-component (e.g., UE-to-UE) communication options.

[0060] Figure 2 Describes the Figure 1 An exemplary logical architecture of a distributed radio access network (RAN) 200 implemented in the wireless communication network 100 is shown. The 5G access node 206 may include an access node controller (ANC) 202. The ANC 202 may be a central unit (CU) of the distributed RAN 200. A backhaul interface for a next generation core network (NG-CN) 204 may terminate at the ANC 202. A backhaul interface for an adjacent next generation access node (NG-AN) 210 may terminate at the ANC 202. The ANC 202 may include one or more transmission reception points (TRPs) 208 (e.g., cells, BSs, gNBs, etc.).

[0061] The TRP 208 may be a distributed unit (DU). The TRP 208 may be connected to a single ANC (e.g., ANC 202) or to more than one ANC (not shown). For example, for RAN sharing, Radio as a Service (RaaS), and service-specific ANC deployments, the TRP 208 may be connected to more than one ANC. Each TRP 208 may include one or more antenna ports. The TRP 208 may be configured to serve traffic for the UE individually (e.g., dynamically selected) or jointly (e.g., joint transmission).

[0062] The logical architecture of the distributed RAN 200 can support various backhaul and fronthaul solutions. This support can be achieved across different deployment types. For example, the logical architecture can be based on the transmission network capabilities (e.g., bandwidth, latency and / or jitter).

[0063] The logical architecture of the distributed RAN 200 may share features and / or components with LTE. For example, the next generation access node (NG-AN) 210 may support dual connectivity with NR and may share a common fronthaul for LTE and NR.

[0064] The logical architecture of the distributed RAN 200 may enable cooperation between TRPs 208, for example, cooperation may be achieved within and / or across TRPs via the ANC 202. An inter-TRP interface may not be used.

[0065] Logical functions can be dynamically distributed in the logical architecture of the distributed RAN 200. Figure 5 As further described in detail, the radio resource control (RRC) layer, the packet data convergence protocol (PDCP) layer, the radio link control (RLC) layer, the medium access control (MAC) layer and the physical (PHY) layer can be adaptively arranged at the DU (e.g., TRP 208) or the CU (e.g., ANC202).

[0066] Figure 3 According to aspects of the present disclosure, an exemplary physical architecture of a distributed radio access network (RAN) 300 is shown. A centralized core network unit (C-CU) 302 may own core network functions. The C-CU 302 may be centrally deployed. C-CU 302 functions may be offloaded (e.g., to Advanced Wireless Services (AWS)) to best handle peak capacity.

[0067] A centralized RAN unit (C-RU) 304 may host one or more ANC functions. Optionally, the C-RU 304 may host core network functions locally. The C-RU 304 may have a distributed deployment. The C-RU 304 may be close to the network edge.

[0068] The DU 306 may have one or more TRPs (edge ​​node (EN), edge unit (EU), radio head (RH), smart radio head (SRH), etc.) The DU may be located at the edge of the network with radio frequency (RF) capabilities.

[0069] Figure 4 BS 110 and UE 120 (eg Figure 1 ) that may be used to implement aspects of the present disclosure. For example, antenna 452, processors 466, 458, 464, and / or controller / processor 480 of UE 120 may be used to perform Fig.10 Operation 1000 of BS 110, and antenna 434, processor 420, 460, 438 and / or controller / processor 440 of BS 110 may be used to perform Fig.11 Operation 1100.

[0070] At BS 110, a transmit processor 420 may receive data from a data source 412 and control information from a controller / processor 440. The control information may be for a physical broadcast channel (PBCH), a physical control format indicator channel (PCFICH), a physical hybrid ARQ indicator channel (PHICH), a physical downlink control channel (PDCCH), a group common PDCCH (GC PDCCH), etc. The data may be for a physical downlink shared channel (PDSCH), etc. The processor 420 may process (e.g., encode and symbol map) the data and control information to obtain data symbols and control symbols, respectively. The processor 420 may also generate reference symbols, e.g., for a primary synchronization signal (PSS), a secondary synchronization signal (SSS), and a cell-specific reference signal (CRS). A transmit (TX) multiple-input multiple-output (MIMO) processor 430 may perform spatial processing (e.g., precoding) on ​​the data symbols, control symbols, and / or reference symbols (if any), and provide output symbol streams to modulators (MODs) 432a to 432t. Each modulator 432 can process a respective output symbol stream (e.g., for OFDM, etc.) to obtain an output sample stream. Each modulator can further process (e.g., convert to analog, amplify, filter, and upconvert) the output sample stream to obtain a downlink signal. The downlink signals from modulators 432a to 432t can be transmitted via antennas 434a to 434t, respectively.

[0071] At the UE 120, antennas 452a to 452r can receive downlink signals from the base station 110 and provide received signals to demodulators (DEMODs) in transceivers 454a to 454r, respectively. Each demodulator 454 can condition (e.g., filter, amplify, downconvert, and digitize) the respective received signals to obtain input samples. Each demodulator can further process the input samples (e.g., for OFDM, etc.) to obtain received symbols. The MIMO detector 456 can obtain received symbols from all demodulators 454a to 454r, perform MIMO detection on the received symbols (if any), and provide detected symbols. The receive processor 458 can process (e.g., demodulate, deinterleave, and decode) the detected symbols, provide decoded data for the UE 120 to the data sink 460, and provide decoded control information to the controller / processor 480.

[0072] On the uplink, at the UE 120, a transmit processor 464 may receive data from a data source 462 (e.g., for a physical uplink shared channel (PUSCH)), receive control information from a controller / processor 480 (e.g., for a physical uplink control channel (PUCCH)), and process the data and control information. The transmit processor 464 may also generate reference symbols for reference signals (e.g., for a sounding reference signal (SRS)). The symbols from the transmit processor 464 may be precoded by the TX MIMO processor 466 (if applicable), further processed by the demodulators in the transceivers 454a through 454r (e.g., for SC-FDM, etc.), and transmitted back to the base station 110. At BS 110, the uplink signal from UE 120 may be received by antenna 434, processed by modulator 432, detected by MIMO detector 436 (if applicable), and further processed by receive processor 438 to obtain decoded data and control information sent by UE 120. Receive processor 438 may provide decoded data to data sink 439 and decoded control information to controller / processor 440.

[0073] Controllers / processors 440 and 480 may direct the operation of base station 110 and UE 120, respectively. Processor 440 and / or other processors and modules at BS 110 may perform or direct the execution of processes for the techniques described herein. Memories 442 and 482 may store data and program codes for BS 110 and UE 120, respectively. Scheduler 444 may schedule UEs for data transmission on the downlink and / or uplink.

[0074] Figure 5According to various aspects of the present disclosure, a diagram 500 showing an example for implementing a communication protocol stack is depicted. The communication protocol stack shown can be implemented by a device operating in a wireless communication system such as a 5G system (e.g., a system supporting uplink-based mobility). Figure 500 depicts a communication protocol stack including a radio resource control (RRC) layer 510, a packet data convergence protocol (PDCP) layer 515, a radio link control (RLC) layer 520, a media access control (MAC) layer 525, and a physical (PHY) layer 530. In various examples, these layers of the protocol stack can be implemented as a separate software module, a part of a processor or ASIC, a part of a non-co-located device connected by a communication link, or various combinations thereof. For example, in a protocol stack for a network access device (e.g., AN, CU, and / or DU) or a UE, co-located and non-co-located implementations can be used.

[0075] The first option 505-a illustrates a split implementation of the protocol stack, in which the implementation of the protocol stack is split between centralized network access devices (e.g., Figure 2 ANC 202 in ) and distributed network access equipment (e.g., Figure 2 In the first option 505-a, the RRC layer 510 and the PDCP layer 515 may be implemented by the central unit, and the RLC layer 520, the MAC layer 525, and the PHY layer 530 may be implemented by the DU. In various examples, the CU and the DU may be co-located or non-co-located. In macro cell, micro cell, or pico cell deployment, the first option 505-a is used.

[0076] The second option 505-b shows a unified implementation of the protocol stack, in which the protocol stack is implemented in a single network access device. In the second option, the RRC layer 510, the PDCP layer 515, the RLC layer 520, the MAC layer 525, and the PHY layer 530 can all be implemented by the AN. The second option 505-b is useful in, for example, a femtocell deployment.

[0077] Regardless of whether the network access device implements part of the protocol stack or the entire protocol stack, the UE can implement the entire protocol stack (e.g., RRC layer 510, PDCP layer 515, RLC layer 520, MAC layer 525 and PHY layer 530), as shown in 505-c.

[0078] The embodiments discussed herein may include a variety of spacing and timing deployments. For example, in LTE, the basic transmission time interval (TTI) or packet duration is a 1ms subframe. In NR, the subframe is still 1ms, but the basic TTI is called a time slot. A subframe contains a variable number of time slots (e.g., 1, 2, 4, 8, 16 time slots) depending on the subcarrier spacing. An NR RB is 12 consecutive frequency subcarriers. NR can support a basic subcarrier spacing of 15KHz, and other subcarrier spacings (e.g., 30kHz, 60kHz, 120kHz, 240kHz, etc.) can be specified relative to the basic subcarrier spacing. Symbol and time slot lengths scale with the subcarrier spacing. The CP length also depends on the subcarrier spacing.

[0079] Figure 6 is a diagram showing an example of a frame format 600 for NR. The transmission timeline for each of the downlink and uplink may be divided into units of radio frames. Each radio frame may have a predetermined duration (e.g., 10 ms), and each radio frame may be divided into 10 subframes indexed from 0 to 9, each subframe being 1 ms. Each subframe may include a variable number of slots depending on the subcarrier spacing. Each slot may include a variable number of symbol periods (e.g., 7 or 14 symbols) depending on the subcarrier spacing. An index may be assigned to the symbol period in each slot. A microslot is a subslot structure (e.g., 2, 3, or 4 symbols).

[0080] Each symbol in a time slot may indicate a link direction (e.g., DL, UL, or flexible) for data transmission, and the link direction may be switched dynamically for each subframe. The link direction may be based on the time slot format. Each time slot may include DL / UL data and DL / UL control information.

[0081] In NR, a synchronization signal (SS) block (SSB) is transmitted. The SS block includes PSS, SSS and two symbols PBCH. It can be transmitted at a fixed time slot position (e.g. Figure 6 PBCH carries some basic system information, such as downlink system bandwidth, timing information within a radio frame, SS burst set period, system frame number, etc.

[0082] Other system information such as Remaining Minimum System Information (RMSI), System Information Blocks (SIBs), Other System Information (OSI) may be sent on a Physical Downlink Shared Channel (PDSCH) in certain subframes.

[0083] like Figure 7 As shown in the figure, SS blocks can be organized into SS burst sets to support beam scanning. As shown in the figure, each SSB in the burst set can be sent using a different beam, which can help the UE quickly acquire the transmit (Tx) beam and receive (Rx) beam (especially for mmW applications). The physical cell identity (PCI) can still be decoded from the PSS and SSS of the SSB.

[0084] Certain deployment scenarios may include one or both NR deployment options. Some may be configured as non-standalone (NSA) and / or standalone (SA) options. Standalone cells may need to broadcast SSBs and remaining minimum system information (RMSI) (e.g., using SIB1 and SIB2). Non-standalone cells may only need to broadcast SSBs without broadcasting RMSI. In a single carrier of NR, multiple SSBs may be sent on different frequencies and may include different types of SSBs.

[0085] Control Resource Set (CORESET)

[0086] A control resource set (CORESET) for an OFDMA system (e.g., a communication system that uses an OFDMA waveform to send a PDCCH) may include one or more sets of control resources (e.g., time and frequency resources) that are configured to transmit a PDCCH within the system bandwidth. Within each CORESET, one or more search spaces (e.g., a common search space (CSS), a UE-specific search space (USS), etc.) may be defined for a given UE. A search space is typically an area or portion in which a communication device (e.g., a UE) may search for control information.

[0087] According to various aspects of the present disclosure, a CORESET is a set of time domain and frequency domain resources defined in units of resource element groups (REGs). Each REG may include a fixed number (e.g., twelve) tones in a symbol period (e.g., a symbol period of a time slot), wherein one tone in one symbol period is called a resource element (RE). A fixed number of REGs may be included in a control channel element (CCE). A CCE set may be used to send a new radio PDCCH (NR-PDCCH), wherein different numbers of CCEs in the set are used to send NR-PDCCH using different aggregation levels. Multiple CCE sets may be defined as search spaces for UEs, so a NodeB or other base station may send NR-PDCCH to a UE by sending NR-PDCCH in a set of CCEs defined as decoding candidates within the UE's search space, and the UE may receive the NR-PDCCH by searching in the UE's search space and decoding the NR-PDCCH sent by the NodeB.

[0088] The operating characteristics of a Node B or other base station in an NR communication system may depend on the frequency range (FR) in which the system operates. The frequency range may include one or more operating bands (e.g., "n1" band, "n2" band, "n7" band, and "n41" band), and the communication system (e.g., one or more NodeBs and UEs) may operate within one or more operating bands. Frequency ranges and operating bands are described in more detail in "Base Station (BS) Radio Transmission and Reception" TS38.104 (Release 15), which is available from the 3GPP website.

[0089] As described above, a CORESET is a set of time domain and frequency domain resources. A CORESET can be configured to transmit a PDCCH within the system bandwidth. The UE can determine the CORESET and monitor the CORESET within the control channel. During initial access, the UE can identify the initial CORESET (CORESET#0) configuration from a field in the master information block (MIB) (e.g., pdcchConfigSIB1). The initial CORESET can then be used to configure the UE (e.g., to configure other CORESETs and / or bandwidth portions through dedicated (UE-specific) signaling). When the UE detects a control channel in the CORESET, the UE attempts to decode the control channel and communicate with the sending base station (e.g., the sending cell) based on the control data provided in the control channel (e.g., sent via the CORESET).

[0090] According to various aspects of the present disclosure, when a UE is connected to a cell (or BS), the UE may receive a MIB. The MIB may be in a synchronization signal and physical broadcast channel (SS / PBCH) block on a sync raster (e.g., in the PBCH of a SS / PBCH block). In some scenarios, the sync raster may correspond to an SSB. Based on the frequency of the sync raster, the UE may determine the operating frequency band of the cell. Based on the operating frequency band of the cell, the UE may determine the minimum channel bandwidth and subcarrier spacing (SCS) of the channel. The UE may then determine an index from the MIB (e.g., four bits in the MIB that convey an index in the range of 0-15).

[0091] Given this index, the UE can look up or locate the CORESET configuration (the initial CORESET configured through the MIB is typically referred to as CORESET#0). This can be done through one or more tables of CORESET configurations. These configurations (which include single-table scenarios) may include various subsets of indices indicating valid CORESET configurations for various combinations of minimum channel bandwidth and SCS. In some arrangements, each combination of minimum channel bandwidth and SCS may be mapped to a subset of indices in the table.

[0092] Alternatively or additionally, the UE may select a search space CORESET configuration table from some CORESET configuration tables. These configurations may be based on the minimum channel bandwidth and the SCS. The UE may then look up the CORESET configuration (e.g., Type0-PDCCH search space CORESET configuration) from the selected table based on the index. After determining the CORESET configuration (e.g., from a single table or a selected table), the UE may determine the CORESET to monitor based on the location (in time and frequency) of the SS / PBCH blocks and the CORESET configuration (as described above).

[0093] Figure 8 An exemplary transmission resource mapping 800 according to aspects of the present disclosure is shown. In the exemplary mapping, a BS (e.g., Figure 1 BS 110a) shown in FIG. sends SS / PBCH block 802. SS / PBCH block 802 includes a MIB that conveys an index to a table that correlates the time and frequency resources of CORESET 804 with the time and frequency resources of SS / PBCH block 802.

[0094] The BS may also send control signaling. In some scenarios, the BS may also send control signaling to the UE (e.g., Figure 1 806. The BS then sends the PDSCH 806 to the UE. The UE may receive the MIB in the SS / PBCH block 802, determine the index, look up the CORESET configuration based on the index, and determine the CORESET based on the CORESET configuration and the SS / PBCH block 802. The UE may then monitor the CORESET, decode the PDCCH in the CORESET, and receive the PDSCH allocated by the PDCCH.

[0095] Different CORESET configurations may have different parameters for defining the corresponding CORESET. For example, each configuration may indicate the number of resource blocks (e.g., 24, 48, or 96), the number of symbols (e.g., 1-3), and an offset indicating a location on frequency (e.g., 0-38 RBs).

[0096] QCL port and TCI status

[0097] In many cases, it may be important for the UE to know which assumptions it can make on the channels corresponding to different transmissions. For example, the UE may need to know which reference signals it can use to estimate the channel in order to decode a transmitted signal (e.g., PDCCH or PDSCH). It may also be important for the UE to be able to report relevant channel state information (CSI) to the BS (gNB) for scheduling, link adaptation and / or beam management purposes. In NR, information about these assumptions is conveyed using the concepts of Quasi Co-location (QCL) and Transmission Configuration Indicator (TCI) states.

[0098] The QCL assumption is typically defined based on channel properties. According to 3GPP TS 38.214, "Two antenna ports are said to be quasi-co-located if the properties of the channel over which symbols are transmitted on one antenna port can be inferred from the channel over which symbols are transmitted on the other antenna port." These different reference signals may be considered quasi-co-located ("QCL'd") if a receiver (e.g., a UE) can apply channel properties determined by detecting the first reference signal to aid in detecting the second reference signal. The TCI state typically includes configurations such as QCL relationships (e.g., QCL relationships between DL RS and PDSCH DMRS ports in a CSI-RS set).

[0099] In some cases, the UE may be configured with up to M TCI states. The configuration of these M TCI states may be achieved through higher layer signaling, and the UE may be signaled to decode the PDSCH based on a detected PDCCH with a DCI indicating one of these TCI states. Each configured TCI state may include an RS set TCI-RS-SetConfig, which indicates different QCL assumptions between certain source and target signals.

[0100] Fig. 9 An example of association of DL reference signals with corresponding QCL types that may be indicated by TCI-RS-SetConfig is shown.

[0101] exist Fig. 9 In the example of FIG. 1 , a source reference signal (RS) is indicated in the top block and is associated with a target signal indicated in the bottom block. In this context, a target signal generally refers to a signal whose channel properties can be inferred by measuring those of the associated source signal. As described above, the UE can use the source RS to determine various channel parameters based on the associated QCL type, and use these various channel properties (determined based on the source RS) to process the target signal. The target RS is not necessarily the DMRS of the PDSCH, it can be any other RS: PUSCH DMRS, CSIRS, TRS and SRS.

[0102] As shown, each TCI-RS-SetConfig contains parameters. For example, these parameters can configure the quasi-co-location relationship between the reference signals in the RS set and the DM-RS port group of the PDSCH. The RS set contains references to one or two DL RSs and the associated quasi-co-location type (QCL-Type) of each RS configured by the higher-layer parameter QCL-Type.

[0103] like Fig. 9 As shown in , for the case of two DL RSs, the QCL type can be arranged in a variety of ways. For example, the QCL type may be different whether the reference is to the same DL RS or different DL RS. In the example shown, SSB is associated with Class C QCL for P-TRS, while CSI-RS for beam management (CSIRS-BM) is associated with Class D QCL.

[0104] In some scenarios, the QCL information and / or type may depend on or be a function of other information. For example, the quasi-co-location (QCL) type indicated to the UE may be based on a higher layer parameter QCL-Type and may be one or a combination of the following types:

[0105] QCL Type A: {Doppler shift, Doppler spread, average delay, delay spread},

[0106] QCL type B: {Doppler shift, Doppler spread},

[0107] QCL Type C: {average delay, Doppler shift} and

[0108] QCL type D: {spatial Rx parameters},

[0109] A spatial QCL assumption (QCL-Type D) may be used to help the UE select an analog Rx beam (e.g., during a beam management procedure). For example, an SSB resource indicator may indicate that the same beam of a previous reference signal should be used for subsequent transmissions.

[0110] The initial CORESET in the NR (e.g., CORESET ID 0 or simply CORESET#0) may be identified (e.g., by a field in the MIB) during initial access of the UE. The ControlResourceSet information element (CORESET IE) sent via radio resource control (RRC) signaling may convey information about the CORESET configured for the UE. The CORESET IE typically includes the CORESET ID, an indication of the frequency domain resources allocated to the CORESET (e.g., the number of RBs), the continuous duration of the CORESET in multiple symbols, and a transmission configuration indicator (TCI) state.

[0111] As described above, a subset of TCI states provides a quasi-co-location (QCL) relationship between DL RS and PDCCH demodulation RS (DMRS) ports in an RS set (e.g., TCI-Set). A specific TCI state (e.g., for unicast PDCCH) for a given UE may be transmitted to the UE via a media access control (MAC) control element (MAC-CE). A specific TCI state is typically selected from a set of TCI states transmitted by a CORESET IE, where an initial CORESET (CORESET#0) is typically configured via the MIB.

[0112] Search space information may also be provided via RRC signaling. For example, the Search Space IE is another RRC IE that defines how and where to search for PDCCH candidates for a given CORESET. Each search space is associated with a CORESET. The Search Space IE identifies the search space configured for the CORESET by the Search Space ID. In one aspect, the Search Space ID associated with CORESET#0 is Search Space ID#0. Search spaces are typically configured via PBCH (MIB).

[0113] Example Techniques for UE Capability Signaling with Respect to SCell BFR

[0114] Some systems such as NR support carrier aggregation (CA). With CA, a UE can communicate with a BS (or multiple BSs) using multiple carriers / cells. CA involves a primary cell (Pcell) and at least one secondary cell (Scell). A Scell ​​can be configured with downlink only or with both uplink and downlink.

[0115] Pcells and Scells may be in different frequency bands. For example, frequency range 1 (FR1) includes, for example, a frequency band below 6 GHz, and frequency range 2 (FR2) includes, for example, a frequency band from 24.25 GHz to 52.6 GHz. In one embodiment, Pcells are in one frequency range (e.g., FR1, below 6 GHz) and Scells are in another frequency range (FR2, 28 GHz).

[0116] Pcell and Scell ​​may use different tone spacing or subcarrier spacing (SCS), resulting in different symbol lengths for Pcell and Scell. For example, in FR2, the symbol length of 120KHz SCS is eight times shorter than the symbol length of 15kHz SCS in FR1.

[0117] In FR2 (mmW communication), directional beamforming can be used between the UE and the gNB. Therefore, the UE and the gNB communicate via a beam pair link (BPL), which can be a corresponding transmit beam and a receive beam on each side of the communication. In some cases, the UE can detect a beam failure (e.g., RSRP error for the BPL) and send a beam failure recovery request (BFRQ) to the gNB. This BFR procedure can be cell-specific (e.g., there can be PCell BFR and SCell BFR).

[0118] As described above, various aspects of the present disclosure relate to beam failure detection and recovery. In some systems, narrow beam transmission and reception can be used to improve the link budget of millimeter wave (mmW) frequencies, but may be susceptible to beam failure. In mmW, directional beamforming is used between the UE and the BS, and the UE and the BS communicate via a beam pair link (BPL). Beam failure generally refers to a situation where the beam quality is below a threshold, which may lead to a radio link failure (RLF). NR supports lower layer signaling to recover from beam failure, which is called beam recovery. For example, instead of initiating cell reselection when the beam quality becomes too low, beam pair reselection can be performed within the cell.

[0119] A beam failure may be detected by monitoring a beam failure detection (BFD) reference signal (RS) and evaluating whether a beam failure trigger condition is met. The UE may monitor the BFD RS from the Scell. In some examples, beam failure detection is triggered if the estimated block error rate (BLER) of the reference signal associated with the configured control resource set (CORESET) is above a threshold (e.g., 10%). In some examples, the UE detects a beam failure when the reference signal received power (RSRP) of the BPL is below a threshold.

[0120] To recover the Scell, the UE may send a beam failure request (BFRQ) message on another cell. In some examples, the BFRQ is sent on the Pcell. In an NR system, a two-step BFRQ may be used. The BFRQ may request a new transmission. After detecting a beam failure, the UE may send the first step (or first phase) of the BFRQ. The first step of the BFRQ message may include a scheduling request (SR) on the Pcell. The SR may be sent on a dedicated SR resource. The SR may request scheduling of the second step (or second phase) of the BFRQ message. The UE may receive a PDCCH from the Pcell in response to the SR to schedule a second group of BFRQ messages. The UE then sends the second step of scheduling the BFRQ message on the Pcell. For example, the UE sends a PUSCH including a MAC-CE. In some embodiments, the MAC-CE may include an index of the failed CC and a new recovery beam candidate beam. In some examples, in order to find a candidate new beam, the UE may monitor a beam identification reference signal.

[0121] The Pcell responds to the BFRQ by sending a beam failure recovery response (BFRR) message to the UE. The BFRR message can confirm the MAC-CE and include an uplink grant that schedules a new transmission. For example, the uplink grant can schedule the transmission of the same HARQ process as the PUSCH that carries the MAC-CE in step 2 of the BFRQ. In some examples, the BFRR is sent by the UE monitoring the CORESET that responds (e.g., called CORESET BFR).

[0122] If a response is successfully received, beam recovery is complete and a new BPL can be established. If the UE does not detect any response within a certain period of time, the UE may perform a retransmission of the request. If the UE does not detect any response after a specified number of retransmissions, the UE may notify higher layers, which may result in RLF and cell reselection.

[0123] According to an embodiment of the present disclosure, the UE may declare its ability to support BFR for one or more SCells by sending a signal to the PCell. For example, the UE may indicate whether the UE supports BFR for any SCell, the maximum number of SCells for which the UE supports BFR (e.g., simultaneously), and / or whether the UE supports sending a BFR request via PUCCH signaling. In some embodiments, the UE may indicate that BFR is not supported by indicating that the maximum number of SCells for which the UE supports BFR is 0, and indicates that the UE supports BFR by indicating that the maximum number of SCells for which the UE supports BFR is greater than 0, rather than separately indicating whether the UE supports BFR for any SCell and the maximum number of SCells for which the UE supports BFR.

[0124] Sending this capability information to the PCell allows the PCell to understand the UE's capabilities regarding BFR, thereby avoiding repeated monitoring of the SCell by the PCell. In addition, receiving the maximum number of SCells that the UE supports BFR allows the PCell to configure different SRs (e.g., PUCCH) to identify which SCell has a beam failure. In one embodiment, the PCell configures an SR for each SCell for which the UE supports BFR for use by the UE. Therefore, if the UE sends a BFR request via a given SR (e.g., SR1), the PCell can determine that a given SCell (e.g., SCell1) corresponding to the given SR has a beam failure. In these embodiments, the UE may not need to indicate which SCell has a beam failure in the BFR request because the SR used to send the BFR request indicates the SCell.

[0125] Example Operations for Signaling UE Capabilities for SCell BFR

[0126] Fig.10 1 is a flow diagram illustrating example operations 1000 for wireless communications of a UE in accordance with certain aspects of the present disclosure. Operations 1000 may be performed, for example, by a UE 120 to signal UE capabilities of SCell BFR.

[0127] Operations 1000 begin at 1002 by first reporting to a network entity the UE's ability to support beam failure recovery (BFR) on one or more secondary cells (SCells).

[0128] At 1004, the UE detects a beam failure of a beam pair link (BPL) associated with a Scell ​​in the one or more SCells.

[0129] At 1006, in response to the detection, the UE performs BFR according to the reported capabilities.

[0130] Fig.11 is a flow chart illustrating example operations 1100 for wireless communication of a network entity, which may be considered to be Fig.10 The operation 1100 may be a complementary operation of the operation 1000. For example, the operation 1100 may be performed, for example, by the BS 110 (eg, a gNB) to perform actions related to the UE capability of the SCell BFR.

[0131] Operations 1100 begin at 1102 by first receiving, from a user equipment (UE), an indication of the UE's ability to support beam failure recovery (BFR) on one or more secondary cells (SCells).

[0132] At 1104, the network entity receives, from the UE, an indication of a detected beam failure of a beam pair link (BPL) associated with an Scell ​​in one or more SCells.

[0133] At 1106, in response to receiving the indication of the detected beam failure, the network entity takes action according to the reported capability to initiate BFR.

[0134] according to Fig.10 and Fig.11 For the UE capability signaling for SCell BFR of operations 1000 and 1100, please refer to Fig.12 The example flowchart can be used to understand.

[0135] like Fig.12 As shown in , the UE may first send SCell BFR capability information to a network entity (e.g., a gNB or RRH). For example, the capability information may include an indication of whether the UE supports SCell BFR, a maximum number of SCells that the UE supports BFR, and / or an indication of whether the UE has the capability to send a BFR request via PUCCH signaling. In some embodiments, the UE indicates that there is no BFR capability by sending a value of 0 for the maximum number of SCells that the UE supports BFR.

[0136] Then, the UE receives the BFD RS from the SCell. In some embodiments, if the quality metric of the reference signal is above or below a threshold, beam failure detection is triggered. The UE detects BFD based on the BFD RS from the SCell.

[0137] To recover the Scell, the UE sends a beam failure request (BFRQ) message to the PCell. In some embodiments, a two-step BFRQ may be used. The BFRQ may request a new transmission. In some embodiments, the UE sends a scheduling request (SR) and / or a PUSCH including a MAC-CE. The MAC-CE may include an index of the failed CC and / or a new recovery beam candidate beam. In an alternative embodiment, the UE does not indicate the index of the failed CC, as this may be indicated by the SR used to send the BFRQ. In some examples, in order to find a candidate new beam, the UE may monitor a beam identification reference signal. In certain embodiments, the BFR request is sent via PUCCH signaling.

[0138] The PCell responds to the BFR request with an acknowledgment. In some embodiments, the PCell sends a beam failure recovery response (BFRR) message to the UE. The BFRR message may acknowledge the MAC-CE and include an uplink grant that schedules a new transmission. For example, the uplink grant may schedule the transmission of the same HARQ process as the PUSCH that carries the MAC-CE in step two of the BFRQ. In some examples, the BFRR is sent by the UE monitoring the CORESET for the response (e.g., referred to as CORESET BFR). If the response is successfully received, the beam recovery is completed and a new BPL can be established. If the UE does not detect any response within a specific time period, the UE may perform a requested retransmission. If the UE does not detect any response after a specified number of retransmissions, the UE may notify higher layers, which may result in RLF and cell reselection.

[0139] While some embodiments involve the UE signaling candidate beams for recovery, other embodiments involve the PCell selecting candidate beams for recovery and / or triggering a process by which candidate beams may be selected.

[0140] Fig.13 An example 1300 of UE capability signaling for SCell BFR is shown. The example capability signaling indicates: 1) whether the UE supports SCell BFR; 2) the maximum number of SCells configured for BFR; 3) whether the UE has the capability to send a BFR request via PUCCH signaling. It should be noted that some of these indications may be excluded from or combined into a single indication. For example, whether the UE supports SCell BFR may be indicated by whether the maximum number of SCells that the UE supports BFR is 0 or some other number.

[0141] Fig.14 A communication device 1400 is shown that may include various components (eg, corresponding to unit functional components), wherein these components are configured to perform operations of the techniques disclosed herein, such as Fig.10 . The communication device 1400 includes a processing system 1402 coupled to a transceiver 1408 (e.g., a transmitter and / or a receiver). The transceiver 1408 is configured to send and receive signals for the communication device 1400, such as the various signals described herein, via an antenna 1410. The processing system 1402 can be configured to perform processing functions of the communication device 1400, including processing signals received and / or transmitted by the communication device 1400.

[0142] The processing system 1402 includes a processor 1404 coupled to a computer-readable medium / memory 1412 via a bus 1406. In some aspects, the computer-readable medium / memory 1412 is configured to store instructions (e.g., computer-executable code) that, when executed by the processor 1404, cause the processor 1404 to perform Fig.10 The operations shown or other operations for performing various techniques for wireless communication of a user equipment (UE) discussed herein. In some aspects, the computer-readable medium / memory 1412 stores: code 1414 for reporting to a network entity the ability of the UE to support beam failure recovery (BFR) on one or more secondary cells (SCells); code 1416 for detecting a beam failure of a beam pair link (BPL) associated with an Scell ​​in one or more SCells; and code 1418 for performing BFR according to the reported capability in response to the detection. In some aspects, each of the codes 1414-1418 can be considered a unit for performing the indicated function.

[0143] In certain aspects, the processor 1404 has circuitry configured to implement code stored in the computer-readable medium / memory 1412. The processor 1404 includes: a circuit 1420 for reporting to a network entity the ability of the UE to support beam failure recovery (BFR) on one or more secondary cells (SCells); a circuit 1424 for detecting a beam failure of a beam pair link (BPL) associated with an Scell ​​in one or more SCells; and a circuit 1426 for performing BFR according to the reported capability in response to the detection. In certain aspects, each of the circuits 1420-1426 can be considered a means for performing the indicated function.

[0144] Fig.15 A communication device 1500 is shown that may include various components (eg, corresponding to unit functional components), wherein these components are configured to perform operations of the techniques disclosed herein, such as Fig.11 . The communication device 1500 includes a processing system 1502 coupled to a transceiver 1508 (e.g., a transmitter and / or a receiver). The transceiver 1508 is configured to send and receive signals for the communication device 1500, such as the various signals described herein, via an antenna 1510. The processing system 1502 can be configured to perform processing functions of the communication device 1500, including processing signals received and / or transmitted by the communication device 1500.

[0145] The processing system 1502 includes a processor 1504 coupled to a computer-readable medium / memory 1512 via a bus 1506. In some aspects, the computer-readable medium / memory 1512 is configured to store instructions (e.g., computer-executable code) that, when executed by the processor 1504, cause the processor 1504 to perform Fig.11 The operations shown or other operations for performing various techniques for wireless communication by network entities discussed herein. In certain aspects, the computer-readable medium / memory 1512 stores: code 1514 for receiving from a user equipment (UE) an indication of the UE's ability to support beam failure recovery (BFR) on one or more secondary cells (SCells); code 1516 for receiving from the UE an indication of a detected beam failure of a beam pair link (BPL) associated with an Scell ​​in one or more SCells; and code 1518 for taking action based on the reported capability to initiate BFR in response to receiving an indication of a detected beam failure.

[0146] In certain aspects, the processor 1504 has circuitry configured to implement code stored in the computer-readable medium / memory 1512. The processor 1504 includes: a circuit 1520 for receiving from a user equipment (UE) an indication of the UE's ability to support beam failure recovery (BFR) on one or more secondary cells (SCells); a circuit 1524 for receiving from the UE an indication of a detected beam failure of a beam pair link (BPL) associated with an Scell ​​in one or more SCells; and a circuit 1526 for taking action according to the reported capability to initiate BFR in response to receiving an indication of a detected beam failure. In certain aspects, each of the circuits 1520-1526 can be considered a means for performing the indicated function.

[0147] Sample Clauses

[0148] Implementation examples are described in the following numbered clauses:

[0149] Clause 1: A method for wireless communications for a user equipment (UE) comprises: reporting to a network entity the ability of the UE to support beam failure recovery (BFR) on one or more secondary cells (SCells); detecting a beam failure of a beam pair link (BPL) associated with a Scell ​​in the one or more SCells; and in response to the detection, performing BFR based on the reported capability.

[0150] Clause 2: A method according to clause 1, wherein reporting the capability comprises: reporting a maximum number of SCells for which the UE can support BFR.

[0151] Clause 3: A method according to clause 2, wherein the maximum number of SCells for which the UE can support BFR includes: the maximum number of SCells for which the UE can simultaneously support BFR.

[0152] Clause 4: A method as described in any of clauses 2-3, wherein a specific value is reported to indicate that BFR is not supported on the one or more SCells.

[0153] Clause 5: A method as described in any of clauses 1-4, wherein reporting the capability includes: reporting the ability of the UE to send a BFR request via a physical uplink control channel (PUCCH) transmission.

[0154] Clause 6: The method of clause 5, wherein performing the BFR according to the reported capability comprises sending a BFR request via a PUCCH transmission.

[0155] Clause 7: The method of clause 6, wherein the BFR request indicates a candidate beam to replace the failed beam.

[0156] Clause 8: The method of any of clauses 6-7, further comprising: receiving an acknowledgement of the BFR request from the network entity.

[0157] Clause 9: A method for wireless communications for a network entity, comprising: receiving from a user equipment (UE) an indication of the UE's ability to support beam failure recovery (BFR) on one or more secondary cells (SCells); receiving from the UE an indication of a detected beam failure of a beam pair link (BPL) associated with a Scell ​​in the one or more SCells; and in response to receiving the indication of the detected beam failure, taking action to initiate BFR based on the reported capability.

[0158] Clause 10: A method according to clause 9, wherein the indication of the capability comprises: an indication of a maximum number of SCells for which the UE can support BFR.

[0159] Clause 11: A method according to clause 10, wherein the maximum number of SCells for which the UE can support BFR includes: the maximum number of SCells for which the UE can simultaneously support BFR.

[0160] Clause 12: A method as described in any of clauses 10-11, wherein a specific value is reported to indicate that BFR is not supported on the one or more SCells.

[0161] Clause 13: A method as described in any of clauses 9-12, wherein the indication of the capability comprises an indication of the capability of the UE to send a BFR request via a Physical Uplink Control Channel (PUCCH) transmission.

[0162] Clause 14: The method of clause 13, wherein receiving the indication of the detected beam failure comprises receiving the indication of the detected beam failure via a BFR request.

[0163] Clause 15: A method as set forth in clause 14, wherein the BFR request is received via a PUCCH transmission.

[0164] Clause 16: A method as described in any of clauses 14-15, wherein the BFR request indicates a candidate beam to replace the failed beam.

[0165] Clause 17: An apparatus for wireless communication of a user equipment (UE) comprises: a memory; and a processor coupled to the memory, the memory and the processor being configured to: report to a network entity the ability of the UE to support beam failure recovery (BFR) on one or more secondary cells (SCells); detect a beam failure of a beam pair link (BPL) associated with a Scell ​​in the one or more SCells; and in response to the detection, perform BFR according to the reported capability.

[0166] Clause 18: An apparatus as described in clause 17, wherein reporting the capability includes: reporting a maximum number of SCells for which the UE can support BFR.

[0167] Clause 19: The apparatus of clause 18, wherein the maximum number of SCells for which the UE can support BFR comprises: a maximum number of SCells for which the UE can simultaneously support BFR.

[0168] Clause 20: An apparatus as described in any of clauses 18-19, wherein a specific value is reported to indicate that BFR is not supported on the one or more SCells.

[0169] Clause 21: An apparatus as described in any of clauses 17-20, wherein reporting the capability includes: reporting the ability of the UE to send a BFR request via a physical uplink control channel (PUCCH) transmission.

[0170] Clause 22: The apparatus of clause 21, wherein performing the BFR according to the reported capabilities comprises sending a BFR request via a PUCCH transmission.

[0171] Clause 23: The apparatus of clause 22, wherein the BFR request indicates a candidate beam to replace a failed beam.

[0172] Clause 24: An apparatus for wireless communication of a network entity comprises: a memory; and a processor coupled to the memory, the memory and the processor being configured to: receive from a user equipment (UE) an indication of the UE's ability to support beam failure recovery (BFR) on one or more secondary cells (SCells); receive from the UE an indication of a detected beam failure of a beam pair link (BPL) associated with an Scell ​​in the one or more SCells; and in response to receiving the indication of the detected beam failure, take action based on the reported capability to initiate BFR.

[0173] Clause 25: An apparatus according to clause 24, wherein reporting the capability comprises: reporting a maximum number of SCells that the UE can support BFR.

[0174] Clause 26: An apparatus according to clause 25, wherein the maximum number of SCells for which the UE can support BFR includes: the maximum number of SCells for which the UE can simultaneously support BFR.

[0175] Clause 27: An apparatus as described in any of clauses 25-26, wherein a specific value is reported to indicate that BFR is not supported on the one or more SCells.

[0176] Clause 28: An apparatus as described in any of clauses 24-27, wherein reporting the capability includes reporting the ability of the UE to send a BFR request via a physical uplink control channel (PUCCH) transmission.

[0177] Clause 29: The apparatus of clause 28, wherein performing the BFR in accordance with the reported capability comprises sending a BFR request via a PUCCH transmission.

[0178] Clause 30: The apparatus of clause 29, wherein the BFR request indicates a candidate beam to replace a failed beam.

[0179] Clause 31: A processing system for wireless communications comprising: a memory including computer-executable instructions; and one or more processors configured to execute the computer-executable instructions and cause the processing system to perform a method according to any one of clauses 1-16.

[0180] Clause 32: An apparatus for wireless communication, comprising means for performing the method of any of clauses 1-16.

[0181] Clause 33: A non-transitory computer-readable medium for wireless communications, comprising computer-executable instructions that, when executed by one or more processors of a processing system, cause the processing system to perform the method of any of clauses 1-16.

[0182] Clause 34: A computer program product for wireless communications embodied on a computer-readable storage medium, comprising code for performing the method according to any of clauses 1-16.

[0183] The disclosed methods herein include one or more steps or actions for implementing these methods. Without departing from the scope of protection of the present invention, these method steps and / or actions can be interchangeable. In other words, unless a specific order of steps or actions is specified, the order and / or use of specific steps and / or actions can be modified without departing from the scope of protection of the present invention.

[0184] As used herein, a phrase referring to "at least one of" a list of items refers to any combination of those items, including single members. For example, "at least one of a, b, or c" is intended to cover: a, b, c, ab, ac, bc, and abc, as well as any combination with multiple of the same elements (e.g., aa, aaa, aab, aac, abb, acc, bb, bbb, bbc, cc, and ccc or any other ordering of a, b, and c).

[0185] As used herein, the term "determine" encompasses a wide variety of actions. For example, "determine" may include calculating, computing, processing, deriving, investigating, querying (e.g., querying a table, a database, or other data structure), ascertaining, and the like. In addition, "determine" may also include receiving (e.g., receiving information), accessing (e.g., accessing data in a memory), and the like. In addition, "determine" may also include resolving, selecting, choosing, establishing, and the like.

[0186] To enable any person of ordinary skill in the art to implement the various aspects described herein, the above description is made around various aspects. It is obvious to those of ordinary skill in the art that various modifications to these aspects are possible, and the general principles defined herein may also be applicable to other aspects. Therefore, the present invention is not limited to the aspects shown herein, but is consistent with the full scope of the present invention, wherein, unless otherwise specified, modifying a certain component in the singular form does not mean "one and only one", but may be "one or more". Unless otherwise specifically stated, the term "some" refers to one or more. All structural and functional equivalents of the components of the various aspects described throughout the present disclosure are expressly incorporated herein by reference, and are intended to be covered by the claims, and these structural and functional equivalents are known or will be known to those of ordinary skill in the art. In addition, no disclosure herein is intended to be dedicated to the public, regardless of whether such disclosure is clearly recorded in the claims. In addition, any claim element should not be interpreted under 35 U.S.C. §112(f) unless the element is explicitly recited using the wording of “functional means” or, in a method claim, the element is recited using the wording of “functional step.”

[0187] The various operations of the methods described above may be performed by any suitable unit capable of performing the corresponding functions. These units may include various hardware and / or software components and / or modules, including but not limited to: circuits, application specific integrated circuits (ASICs) or processors. Generally, where operations are shown in the accompanying drawings, these operations may have corresponding paired functional module components that are similarly numbered.

[0188] A general purpose processor, digital signal processor (DSP), application specific integrated circuit (ASIC), field programmable gate array (FPGA) or other programmable logic device (PLD), discrete gate or transistor logic, discrete hardware components or any combination thereof for performing the functions described herein may implement or perform various exemplary logic blocks, modules and circuits described in conjunction with the contents disclosed herein. A general purpose processor may be a microprocessor, or the processor may be any commercially available processor, controller, microcontroller or state machine. A processor may also be implemented as a combination of computing devices, for example, a combination of a DSP and a microprocessor, a plurality of microprocessors, a combination of one or more microprocessors and a DSP core, or any other such structure.

[0189] When implemented in hardware, an exemplary hardware configuration may include a processing system in a wireless node. The processing system may be implemented using a bus architecture. Depending on the specific application and overall design constraints of the processing system, the bus may include any number of interconnected buses and bridges. The bus may link together various circuits including a processor, a machine-readable medium, and a bus interface. The bus interface may be used to connect a network adapter, etc., to the processing system via the bus. The network adapter may be used to implement signal processing functions at the physical layer. In the user terminal 120 (see Figure 1 ), a user interface (e.g., keyboard, display, mouse, joystick, etc.) may also be connected to the bus. The bus also links various other circuits such as clock sources, peripherals, voltage regulators, power management circuits, etc., which are well known in the art and are not described any further. The processor may be implemented using one or more general purpose processors and / or special purpose processors. Examples include microprocessors, microcontrollers, DSP processors, and other circuits capable of executing software. One of ordinary skill in the art will recognize how to best implement the described functionality of the processing system depending on the specific application and the overall design constraints imposed on the entire system.

[0190] When implemented using software, these functions can be stored on a computer-readable medium or transmitted as one or more instructions or codes on a computer-readable medium. Software should be broadly interpreted as meaning instructions, data, or any combination thereof, etc., whether it is referred to as software, firmware, middleware, microcode, hardware description language, or other terms. Computer-readable media include computer storage media and communication media, wherein the communication medium includes any medium that facilitates the transmission of a computer program from one place to another. The processor can be responsible for managing the bus and general processing, which includes executing the software stored on the machine-readable storage medium. The computer-readable storage medium can be coupled to the processor so that the processor can read information from the storage medium and write information to the storage medium. Alternatively, the storage medium can also be a part of the processor. For example, the machine-readable medium can include a transmission line, a carrier waveform modulated with data, and / or a computer-readable storage medium with instructions stored thereon separated from the wireless node, all of which can be accessed by the processor through a bus interface. Alternatively or additionally, the machine-readable medium or any part thereof can be a component of the processor, for example, the case can be a cache and / or a general register file. For example, examples of machine-readable storage media may include RAM (random access memory), flash memory, ROM (read-only memory), PROM (programmable read-only memory), EPROM (erasable programmable read-only memory), EEPROM (electrically erasable programmable read-only memory), registers, magnetic disks, optical disks, hard disks, or any other suitable storage media, or any combination thereof. Machine-readable media may be embodied in a computer program product.

[0191] A software module may include a single instruction or multiple instructions, and the software module may be distributed over several different code segments, distributed among different programs, and distributed among multiple storage media. A computer-readable medium may include multiple software modules. These software modules include instructions that, when executed by a device such as a processor, cause a processing system to perform various functions. A software module may include a transmission module and a receiving module. Each software module may be located in a single storage device or distributed among multiple storage devices. For example, when a triggering event occurs, a software module may be loaded from a hard disk into a RAM. During the execution of the software module, the processor may load some of these instructions into a cache to increase access speed. Subsequently, one or more cache lines may be loaded into a general register file for execution by the processor. When referring to the function of the following software module, it should be understood that the function is implemented by the processor when executing instructions from the software module.

[0192] Moreover, any connection may be properly referred to as a computer-readable medium. For example, if the software is transmitted from a website, server or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared (IR), wireless and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, wireless and microwave are included in the definition of the medium. As used herein, disk and disc include compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and Optical disks, where magnetic disks typically reproduce data magnetically, and optical disks use lasers to reproduce data optically. Thus, in some aspects, computer-readable media may include non-transitory computer-readable media (e.g., tangible media). Additionally, for other aspects, computer-readable media may include temporary computer-readable media (e.g., signals). Combinations of the above should also be included within the scope of protection of computer-readable media.

[0193] Thus, some aspects may include a computer program product for performing the operations presented herein. For example, the computer program product may include a computer-readable medium having instructions stored thereon (and / or encoded thereon), which instructions may be executed by one or more processors to perform the operations described herein. For example, a computer program product for performing the operations described herein and in Figure 10-11 Instructions for the operations shown in .

[0194] In addition, it should be understood that the modules and / or other appropriate units for performing the methods and techniques described herein can be downloaded and / or obtained on demand by a user terminal and / or a base station. For example, such a device can be coupled to a server to facilitate the implementation of a unit for transmitting and performing the methods described herein. Alternatively, the various methods described herein can be provided by a storage unit (e.g., RAM, ROM, a physical storage medium such as a compact disc (CD) or a floppy disk, etc.), so that when a user terminal and / or a base station couples the storage unit to or provides it to the device, the various methods can be obtained. In addition, any other appropriate technology for providing the methods and techniques described herein to a device can also be used.

[0195] It should be understood that the present invention is not limited to the precise configuration and components shown above. Various modifications, changes and variations may be made to the arrangement, operation and details of the methods and devices described above without departing from the scope of the present invention.

Claims

1. A method for wireless communication by a user equipment (UE), comprising: reporting, to a network entity, a capability of the UE to support beam failure recovery (BFR) on one or more secondary cells (SCells), wherein reporting the capability comprises reporting a maximum number of SCells for which the UE can simultaneously support BFR; detecting a beam failure of a beam pair link (BPL) associated with an Scell ​​in the one or more SCells; and In response to the detecting, performing a BFR according to the reported capability, wherein performing the BFR comprises: Sending a beam failure request message includes: sending a scheduling request SR on a dedicated SR resource on the PCell; Sending a MAC-CE including the index of the failed CC and a new recovery beam candidate beam; and An uplink grant is received that schedules a new transmission, wherein a new BPL to replace the failed BPL is established based on the new transmission.

2. The method according to claim 1, wherein: Specific values ​​are reported to indicate that BFR is not supported.

3. The method according to claim 1, wherein: Capabilities reported include: Reports the UE's ability to send BFR requests via Physical Uplink Control Channel (PUCCH) transmissions.

4. The method according to claim 3, wherein: Performing the BFR according to the reported capability includes sending a BFR request via a PUCCH transmission.

5. The method according to claim 4, wherein: The BFR request indicates a candidate beam to replace the failed beam.

6. The method according to claim 4, further comprising: An acknowledgement of the BFR request is received from the network entity.

7. A method for wireless communication by a network entity, comprising: receiving, from a user equipment (UE), an indication of a capability of the UE to support beam failure recovery (BFR) on one or more secondary cells (SCells), wherein the indication of the capability comprises an indication of a maximum number of SCells for which the UE can simultaneously support BFR; receiving, from the UE, an indication of a detected beam failure of a beam pair link (BPL) associated with an Scell ​​in the one or more SCells; and In response to receiving the indication of the detected beam failure, performing one or more actions based on the reported capability to simultaneously initiate BFR with respect to two or more Scells, wherein the one or more actions include receiving a beam failure request message and sending an uplink grant to the UE to schedule a new transmission, wherein a new BPL for replacing the failed BPL is established based on the new transmission.

8. The method according to claim 7, wherein: Specific values ​​are reported to indicate that BFR is not supported.

9. The method according to claim 7, wherein: Said indication of said capability comprises: An indication of the ability of the UE to send a BFR request via a Physical Uplink Control Channel (PUCCH) transmission.

10. The method according to claim 9, wherein: Receiving an indication of two or more detected beam failures includes receiving one or more BFR requests.

11. The method according to claim 10, wherein: The one or more BFR requests are received via a PUCCH transmission.

12. The method according to claim 10, wherein: The one or more BFR requests indicate candidate beams to replace the failed beam.

13. An apparatus for wireless communication by a user equipment (UE), comprising: Memory; as well as a processor coupled to the memory, the memory and the processor being configured to: reporting, to a network entity, a capability of the UE to support beam failure recovery (BFR) on one or more secondary cells (SCells), wherein reporting the capability comprises reporting a maximum number of SCells for which the UE can simultaneously support BFR; detecting a beam failure of a beam pair link (BPL) associated with an SCell of the one or more SCells; and In response to the detecting, performing a BFR according to the reported capability, wherein performing the BFR comprises: Sending a beam failure request message includes: sending a scheduling request SR on a dedicated SR resource on the PCell; Sending a MAC-CE including the index of the failed CC and a new recovery beam candidate beam; and An uplink grant is received that schedules a new transmission, wherein a new BPL to replace the failed BPL is established based on the new transmission.

14. The device according to claim 13, wherein: Specific values ​​are reported to indicate that BFR is not supported.

15. The device according to claim 13, wherein: Capabilities reported include: Reports the UE's ability to send BFR requests via Physical Uplink Control Channel (PUCCH) transmissions.

16. The device according to claim 15, wherein: Performing the BFR according to the reported capability includes sending a BFR request via a PUCCH transmission.

17. The device according to claim 16, wherein: The BFR request indicates a candidate beam to replace the failed beam.

18. An apparatus for wireless communication by a network entity, comprising: Memory; as well as a processor coupled to the memory, the memory and the processor being configured to: receiving, from a user equipment (UE), an indication of a capability of the UE to support beam failure recovery (BFR) on one or more secondary cells (SCells), wherein the indication of the capability comprises an indication of a maximum number of SCells for which the UE can simultaneously support BFR; receiving, from the UE, an indication of a detected beam failure of a beam pair link (BPL) associated with an Scell ​​in the one or more SCells; and In response to receiving the indication of the detected beam failure, performing one or more actions based on the reported capability to initiate BFR simultaneously relative to two or more SCells, wherein the one or more actions include receiving a beam failure request message and sending an uplink grant to the UE to schedule a new transmission, wherein a new BPL for replacing the failed BPL is established based on the new transmission.

19. The device according to claim 18, wherein: Specific values ​​are reported to indicate that BFR is not supported.

20. The device according to claim 18, wherein The indication of capability includes: An indication of the ability of the UE to send a BFR request via a Physical Uplink Control Channel (PUCCH) transmission.

21. The device according to claim 20, wherein: Receiving an indication of two or more detected beam failures includes receiving one or more BFR requests.

22. The device according to claim 21, wherein The one or more BFR requests indicate candidate beams to replace the failed beam.

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