Transmitting a beam failure recovery request via a secondary cell used for carrier aggregation

Abstract

Aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may detect a beam failure on a secondary cell (SCell), where the UE is configured with a primary cell (PCell) for carrier aggregation with a base station and the SCell; identify one or more resources for transmitting a beam failure recovery request at least in part based on detecting the beam failure, where the one or more resources are on one or more SCells configured for the UE; and use the one or more resources to transmit the beam failure recovery request to the base station. Numerous other aspects are provided.

Description

[0001] Cross - Reference to Related Applications

[0002] This patent application claims priority to U.S. Provisional Patent Application No. 62 / 902,759, filed on September 19, 2019, entitled "TRANSMISSION OF A BEAM FAILURE RECOVERY REQUEST VIA A SECONDARY CELL USED FOR CARRIER AGGREGATION", and U.S. Non - Provisional Patent Application No. 17 / 014,305, filed on September 8, 2020, entitled "TRANSMISSION OF A BEAM FAILURE RECOVERY REQUEST VIA A SECONDARY CELL USED FOR CARRIER AGGREGATION", which are hereby incorporated by reference in their entirety.

[0003] Field of Disclosure

[0004] Aspects of the present disclosure generally relate to wireless communication, and more particularly, to techniques and devices for transmitting a beam failure recovery request via a secondary cell used for carrier aggregation.

[0005] Background

[0006] Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasting. A typical wireless communication system may employ a multiple access technology capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power, etc.). Examples of such multiple access technologies include Code Division Multiple Access (CDMA) systems, Time Division Multiple Access (TDMA) systems, Frequency Division Multiple Access (FDMA) systems, Orthogonal Frequency Division Multiple Access (OFDMA) systems, Single - Carrier Frequency Division Multiple Access (SC - FDMA) systems, Time Division - Synchronous Code Division Multiple Access (TD - SCDMA) systems, and Long Term Evolution (LTE). LTE / LTE - Advanced is an enhanced set of the Universal Mobile Telecommunications System (UMTS) mobile standards promulgated by the Third Generation Partnership Project (3GPP).

[0007] A wireless communication network may include a plurality of base stations (BSs) capable of supporting communication of several user equipments (UEs). A user equipment (UE) may communicate with a base station (BS) via a downlink and an uplink. The downlink (or forward link) refers to the communication link from the BS to the UE, and the uplink (or reverse link) refers to the communication link from the UE to the BS. As will be described in more detail herein, a BS may be referred to as a B node, a gNB, an access point (AP), a radio head, a transmission reception point (TRP), a new radio (NR) BS, a 5G B node, and so on.

[0008] The above multi-access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different user equipments to communicate at the urban, national, regional, and even global levels. New radio (NR) (which may also be referred to as 5G) is an enhanced set of the LTE mobile standard promulgated by the 3rd Generation Partnership Project (3GPP). NR is designed to better support mobile broadband Internet access by improving spectral efficiency, reducing costs, improving services, utilizing new spectrums, and using orthogonal frequency division multiplexing (OFDM) with cyclic prefix (CP) (CP-OFDM) on the downlink (DL), and CP-OFDM and / or SC-FDM (e.g., also referred to as discrete Fourier transform spread OFDM (DFT-s-OFDM)) on the uplink (UL), and supporting beamforming, multiple input multiple output (MIMO) antenna technology, and carrier aggregation to better integrate with other open standards. However, as the demand for mobile broadband access continues to grow, there is a need for further improvement in LTE and NR technologies. Preferably, these improvements should be applicable to other multi-access technologies and telecommunication standards that employ these technologies.

[0009] Summary

[0010] In some aspects, a wireless communication method performed by a user equipment (UE) may include: detecting a beam failure on a secondary cell (SCell), where the UE is configured with a primary cell (PCell) for carrier aggregation with a base station and the SCell; identifying, at least in part based on detecting the beam failure, one or more resources for transmitting a beam failure recovery request, where the one or more resources are on one or more SCells configured for the UE; and using the one or more resources to transmit the beam failure recovery request to the base station.

[0011] In some aspects, a wireless communication method performed by a base station may include: communicating with a UE using a PCell and an SCell for carrier aggregation; receiving, from the UE, a beam failure recovery request for the SCell, where the beam failure recovery request is received on one or more resources configured for one or more SCells of the UE; and transmitting a beam failure recovery response to the UE at least in part based on receiving the beam failure recovery request.

[0012] In some aspects, a UE for wireless communication may include a memory and one or more processors operatively coupled to the memory. The memory and the one or more processors may be configured to: identify, at least in part based on detecting the beam failure, one or more resources for transmitting a beam failure recovery request, where the one or more resources are on one or more SCells configured for the UE; and use the one or more resources to transmit the beam failure recovery request to the base station.

[0013] In some aspects, a base station for wireless communication may include a memory and one or more processors operatively coupled to the memory. The memory and the one or more processors may be configured to: communicate with a UE using a PCell and an SCell for carrier aggregation; receive, from the UE, a beam failure recovery request for the SCell, where the beam failure recovery request is received on one or more resources configured for one or more SCells of the UE; and transmit a beam failure recovery response to the UE at least in part based on receiving the beam failure recovery request.

[0014] In some aspects, a non-transitory computer-readable medium may store one or more instructions for wireless communication. The one or more instructions, when executed by one or more processors of a UE, may cause the one or more processors to: identify, at least in part based on detecting the beam failure, one or more resources for transmitting a beam failure recovery request, where the one or more resources are on one or more SCells configured for the UE; and use the one or more resources to transmit the beam failure recovery request to the base station.

[0015] In some aspects, a non-transitory computer-readable medium may store one or more instructions for wireless communication. When executed by one or more processors of a base station, the one or more instructions may cause the one or more processors to: communicate with a UE using a PCell and an SCell for carrier aggregation; receive, from the UE, a beam failure recovery request for the SCell, wherein the beam failure recovery request is received on one or more resources configured for one or more SCells of the UE; and transmit a beam failure recovery response to the UE at least in part based on receiving the beam failure recovery request.

[0016] In some aspects, an apparatus for wireless communication may include: means for detecting a beam failure on an SCell, wherein the apparatus is configured with a PCell and the SCell for carrier aggregation with a base station; means for identifying, at least in part based on detecting the beam failure, one or more resources for transmitting the beam failure recovery request, wherein the one or more resources are on one or more SCells configured for the apparatus; and means for transmitting the beam failure recovery request to the base station using the one or more resources.

[0017] In some aspects, an apparatus for wireless communication may include: means for communicating with a UE using a PCell and an SCell for carrier aggregation; means for receiving, from the UE, a beam failure recovery request for the SCell, wherein the beam failure recovery request is received on one or more resources configured for one or more SCells of the UE; and means for transmitting a beam failure recovery response to the UE at least in part based on receiving the beam failure recovery request.

[0018] Aspects generally include methods, apparatuses, systems, computer program products, non-transitory computer-readable media, user equipment, base stations, wireless communication devices, and / or processing systems substantially as described herein with reference to the figures and the description, as illustrated by the figures and the description.

[0019] The foregoing has outlined rather broadly the features and technical advantages of examples in accordance with the present disclosure so as to enable the detailed description that follows to be better understood. Additional features and advantages will be described hereinafter. The disclosed concepts and specific examples may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes as the present disclosure. Such equivalent constructions do not depart from the scope of the appended claims. The characteristics of the concepts disclosed herein, both as to their organization and operation methods, as well as associated advantages, will be better understood when considered in conjunction with the following description taken in connection with the accompanying figures. Each of the figures is provided for purposes of illustration and description and is not intended to define a limitation of the claims. Brief Description of the Drawings

[0021] To understand the above-described features of the present disclosure in detail, the content briefly summarized above can be described more specifically with reference to various aspects, some of which are illustrated in the accompanying drawings. It should be noted, however, that the drawings only illustrate certain exemplary aspects of the present disclosure and should not be considered to limit its scope, as the description may permit other equally effective aspects. The same reference numerals in different drawings may identify the same or similar elements.

[0022] Figure 1 is a block diagram conceptually illustrating an example of a wireless communication network in accordance with various aspects of the present disclosure.

[0023] Figure 2 is a block diagram conceptually illustrating an example of a base station and a UE in communication in a wireless communication network in accordance with various aspects of the present disclosure.

[0024] Figure 3 is a diagram illustrating an example of wireless communication via one or more beams in accordance with certain aspects of the present disclosure.

[0025] Figure 4 is a diagram illustrating an example of a beam failure recovery procedure in accordance with certain aspects of the present disclosure.

[0026] Figure 5 is a diagram illustrating an example of transmitting a beam failure recovery request via a secondary cell used for carrier aggregation in accordance with various aspects of the present disclosure.

[0027] Figure 6 is a diagram illustrating an example process, such as performed by a user equipment, in accordance with various aspects of the present disclosure.

[0028] Figure 7 is a diagram illustrating an example process, such as performed by a base station, in accordance with various aspects of the present disclosure.

[0029] Detailed Description

[0030] Aspects of the present disclosure are described more fully hereinafter with reference to the accompanying drawings. However, the present disclosure may be embodied in many different forms and should not be construed as limited to any specific structure or function presented throughout this disclosure. Rather, these aspects are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. Based on the teachings herein, those skilled in the art should appreciate that the scope of the present disclosure is intended to cover any aspect of the present disclosure disclosed herein, whether implemented independently of or in combination with any other aspect of the present disclosure. For example, any number of the aspects set forth herein may be used to implement a device or practice a method. Additionally, the scope of the present disclosure is intended to cover such devices or methods practiced using other structures, functionality, or a combination of structures and functionality that supplement or replace the various aspects of the present disclosure set forth herein. It should be understood that any aspect of the present disclosure disclosed herein may be implemented by one or more elements of a claim.

[0031] Certain aspects of a telecommunications system will now be presented with reference to various devices and technologies. These devices and technologies will be described in detail hereinafter and illustrated in the drawings by various blocks, modules, components, circuits, steps, processes, algorithms, etc. (collectively referred to as "elements"). These elements may be implemented using hardware, software, or a combination thereof. Whether such elements are implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system.

[0032] It should be noted that while aspects may be described herein using terminology typically associated with 3G and / or 4G wireless technologies, aspects of the present disclosure may be applied to other generations of communication systems (such as 5G and later generations, including NR technology).

[0033] Figure 1 FIG. 100 is a diagram illustrating a wireless network 100 in which aspects of the present disclosure may be practiced. The wireless network 100 may be an LTE network or some other wireless network, such as a 5G or NR network. The wireless network 100 may include several BSs 110 (shown as BS 110a, BS 110b, BS 110c, and BS 110d) and other network entities. A BS is an entity that communicates with user equipment (UE) and may also be referred to as a base station, NR BS, Node B, gNB, 5G Node B (NB), access point, transmission reception point (TRP), etc. Each BS may provide communication coverage for a particular geographic area. In 3GPP, the term "cell" may refer to the coverage area of a BS and / or the BS subsystem serving that coverage area, depending on the context in which the term is used.

[0034] The BS can provide communication coverage for macro cells, pico cells, femto cells, and / or another type of cell. A macro cell can cover a relatively large geographical area (e.g., with a radius of several kilometers) and can allow unrestricted access by UEs with service subscriptions. A pico cell can cover a relatively small geographical area and can allow unrestricted access by UEs with service subscriptions. A femto cell can cover a relatively small geographical area (e.g., a residence) and can allow restricted access by UEs associated with the femto cell (e.g., UEs in a Closed Subscriber Group (CSG)). The BS for a macro cell can be referred to as a macro BS. The BS for a pico cell can be referred to as a pico BS. The BS for a femto cell can be referred to as a femto BS or a home BS. In Figure 1 the example shown in, BS 110a can be a macro BS for macro cell 102a, BS 110b can be a pico BS for pico cell 102b, and BS 110c can be a femto BS for femto cell 102c. The BS can support one or more (e.g., three) cells. The terms "eNB", "base station", "NR BS", "gNB", "TRP", "AP", "B node", "5G NB", and "cell" can be used interchangeably herein.

[0035] In some aspects, the cell may not have to be stationary, and the geographical area of the cell can move according to the position of the mobile BS. In some aspects, the BSs can be interconnected with each other and / or interconnected to one or more other BSs or network nodes (not shown) in the wireless network 100 through various types of backhaul interfaces such as direct physical connections, virtual networks, and / or analogs using any suitable transport network.

[0036] The wireless network 100 can also include relay stations. A relay station is an entity that can receive the transmission of data from an upstream station (e.g., a BS or a UE) and send the transmission of the data to a downstream station (e.g., a UE or a BS). A relay station can also be a UE that can relay transmissions for other UEs. In Figure 1 the example shown in, relay station 110d can communicate with macro BS 110a and UE 120d to facilitate communication between BS 110a and UE 120d. The relay station can also be referred to as a relay BS, a relay base station, a relay, etc.

[0037] The wireless network 100 can be a heterogeneous network including different types of BSs (e.g., macro BS, pico BS, femto BS, relay BS, etc.). These different types of BSs may have different transmit power levels, different coverage areas, and different impacts on interference in the wireless network 100. For example, a macro BS may have a high transmit power level (e.g., 5 to 40 watts), while pico BSs, femto BSs, and relay BSs may have lower transmit power levels (e.g., 0.1 to 2 watts).

[0038] The network controller 130 can be coupled to a set of BSs and can provide coordination and control for these BSs. The network controller 130 can communicate with each BS via a backhaul. These BSs can also communicate with each other directly or indirectly, e.g., via a wireless or wired backhaul.

[0039] UEs 120 (e.g., 120a, 120b, 120c) can be dispersed throughout the wireless network 100, and each UE can be stationary or mobile. UEs can also be referred to as access terminals, terminals, mobile stations, subscriber units, stations, etc. A UE can be a cellular phone (e.g., a smart phone), a personal digital assistant (PDA), a wireless modem, a wireless communication device, a handheld device, a laptop computer, a cordless phone, a wireless local loop (WLL) station, a tablet, a camera, a gaming device, a netbook, a smartbook, a ultrabook, a medical device or equipment, a biometric sensor / device, a wearable device (smart watch, smart clothing, smart glasses, smart wristband, smart jewelry (e.g., smart ring, smart bracelet)), an entertainment device (e.g., a music or video device, or a satellite radio), a vehicle component or sensor, a smart meter / sensor, an industrial manufacturing equipment, a global positioning system device, or any other suitable device configured to communicate via a wireless or wired medium.

[0040] Some UEs can be considered machine type communication (MTC) UEs, or evolved or enhanced machine type communication (eMTC) UEs. MTC and eMTC UEs include, for example, robots, drones, remote devices, sensors, meters, monitors, location tags, etc., which can communicate with a base station, another device (e.g., a remote device), or some other entity. A wireless node can provide connectivity to a network (e.g., a wide area network such as the Internet or a cellular network) or provide connectivity to the network, e.g., via a wired or wireless communication link. Some UEs can be considered Internet of Things (IoT) devices, and / or can be implemented as narrowband IoT (NB-IoT) devices. Some UEs can be considered customer premise equipment (CPE). The UE 120 can be included inside a housing that houses components of the UE 120, such as processor components, memory components, etc.

[0041] Generally, any number of wireless networks can be deployed in a given geographical area. Each wireless network can support a specific RAT and can operate on one or more frequencies. The RAT can also be referred to as radio technology, air interface, etc. The frequency can also be referred to as carrier, frequency channel, etc. Each frequency can support a single RAT in a given geographical area to avoid interference between wireless networks of different RATs. In some cases, an NR or 5G RAT network can be deployed.

[0042] In some aspects, two or more UEs 120 (e.g., shown as UE 120a and UE 120e) can communicate directly using one or more sidelink channels (e.g., communicate with each other without using the base station 110 as an intermediary). For example, the UE 120 can communicate using peer-to-peer (P2P) communication, device-to-device (D2D) communication, vehicle-to-everything (V2X) protocols (e.g., which can include vehicle-to-vehicle (V2V) protocol, vehicle-to-infrastructure (V2I) protocol, etc.), mesh network, etc. In this case, the UE 120 can perform scheduling operations, resource selection operations, and / or other operations described elsewhere herein as being performed by the base station 110.

[0043] As indicated above, Figure 1 is provided as an example. Other examples may be different from the examples described with respect to Figure 1 described.

[0044] Figure 2 FIG. shows a block diagram of a design 200 of a base station 110 and a UE 120, where the base station 110 and the UE 120 can be Figure 1 one of the base stations and one of the UEs in. The base station 110 can be equipped with T antennas 234a to 234t, while the UE 120 can be equipped with R antennas 252a to 252r, where generally T≥1 and R≥1.

[0045] At base station 110, a transmit processor 220 may receive data for one or more UEs from a data source 212, select one or more modulation and coding schemes (MCSs) for a UE at least in part based on channel quality indicators (CQIs) received from each UE, process (e.g., encode and modulate) the data for the UE at least in part based on the MCSs selected for each UE, and provide data symbols for all UEs. The transmit processor 220 may also process system information (e.g., for semi-static resource partitioning information (SRPI), etc.) and control information (e.g., CQI requests, grants, upper layer signaling, etc.), and provide overhead symbols and control symbols. The transmit processor 220 may also generate reference symbols for reference signals (e.g., cell-specific reference signals (CRSs)) and synchronization signals (e.g., primary synchronization signal (PSS) and secondary synchronization signal (SSS)). A transmit (TX) multiple-input multiple-output (MIMO) processor 230 may perform spatial processing (e.g., precoding) on the data symbols, control symbols, overhead symbols, and / or reference symbols, if applicable, and may provide T output symbol streams to T modulators (MODs) 232a through 232t. Each modulator 232 may process its respective output symbol stream (e.g., for OFDM, etc.) to obtain an output sample stream. Each modulator 232 may further process (e.g., convert to analog, amplify, filter, and upconvert) the output sample stream to obtain a downlink signal. The T downlink signals from modulators 232a through 232t may be transmitted via T antennas 234a through 234t, respectively. According to various aspects described in more detail below, position coding may be utilized to generate synchronization signals to convey additional information.

[0046] At the UE 120, antennas 252a through 252r may receive downlink signals from the base station 110 and / or other base stations and may provide the received signals to demodulators (DEMOD) 254a through 254r, respectively. Each demodulator 254 may condition (e.g., filter, amplify, down-convert, and digitize) the received signal to obtain input samples. Each demodulator 254 may further process the input samples (e.g., for OFDM, etc.) to obtain received symbols. The MIMO detector 256 may obtain the received symbols from all R demodulators 254a through 254r, perform MIMO detection on the received symbols when applicable, and provide detected symbols. The receive processor 258 may process (e.g., demodulate and decode) the detected symbols, provide the decoded data for the UE 120 to the data sink 260, and provide the decoded control information and system information to the controller / processor 280. The channel processor may determine the reference signal received power (RSRP), received signal strength indicator (RSSI), reference signal received quality (RSRQ), channel quality indicator (CQI), etc. In some aspects, one or more components of the UE 120 may be included in a housing.

[0047] On the uplink, at the UE 120, the transmit processor 264 may receive and process data from the data source 262 and control information from the controller / processor 280 (e.g., for reports including RSRP, RSSI, RSRQ, CQI, etc.). The transmit processor 264 may also generate reference symbols for one or more reference signals. The symbols from the transmit processor 264 may be precoded by the TX MIMO processor 266 when applicable, further processed by modulators 254a through 254r (e.g., for DFT-s-OFDM, CP-OFDM, etc.), and transmitted to the base station 110. At the base station 110, the uplink signals from the UE 120 and other UEs may be received by the antenna 234, processed by the demodulator 232, detected by the MIMO detector 236 when applicable, and further processed by the receive processor 238 to obtain the decoded data and control information transmitted by the UE 120. The receive processor 238 may provide the decoded data to the data sink 239 and provide the decoded control information to the controller / processor 240. The base station 110 may include a communication unit 244 and communicate with the network controller 130 via the communication unit 244. The network controller 130 may include a communication unit 294, a controller / processor 290, and a memory 292.

[0048] The controller / processor 240 of the base station 110, the controller / processor 280 of the UE 120, and / or Figure 2Any other component(s) thereof may perform one or more techniques associated with transmitting a beam failure recovery request via a secondary cell used for carrier aggregation, as described in more detail elsewhere herein. For example, the controller / processor 240 of the base station 110, the controller / processor 280 of the UE 120, and / or Figure 2 Any other component(s) thereof may perform or direct operations of, for example Figure 6 Process 600 of Figure 7 Process 700 of Figure 6 Process 600 of Figure 7 Process 700 of

[0049] and / or other processes described herein. The memories 242 and 282 may store data and program codes for the base station 110 and the UE 120, respectively. In some aspects, the memory 242 and / or the memory 282 may include: a non-transitory computer-readable medium storing one or more instructions for wireless communication. For example, when executed by one or more processors of the base station 110 and / or the UE 120, the one or more instructions may perform or direct operations of, for example Figure 2 Process 600 of

[0050] Process 700 of Figure 2 described components of the UE 120, such as the controller / processor 280, the transmit processor 264, the TX MIMO processor 266, the MOD 254, the antenna 252, the DEMOD 254, the MIMO detector 256, the receive processor 258, and so on.

[0050] In some aspects, the base station 110 may include: means for communicating with the UE using the PCell and the SCell for carrier aggregation; means for receiving, from the UE, a beam failure recovery request for the SCell, where the beam failure recovery request is received on one or more resources configured for one or more SCells of the UE; means for transmitting, at least in part based on receiving the beam failure recovery request, a beam failure recovery response to the UE; and so on. In some aspects, such means may include components of the base station 110 described in conjunction with Figure 2One or more components of the described base station 110, such as antenna 234, DEMOD 232, MIMO detector 236, receive processor 238, controller / processor 240, transmit processor 220, TX MIMO processor 230, MOD 232, antenna 234, and so on.

[0051] As indicated above, Figure 2 is provided as an example. Other examples may be different from the example described with respect to Figure 2 the example.

[0052] Figure 3 is a diagram illustrating example 300 of wireless communication via one or more beams in accordance with certain aspects of the present disclosure.

[0053] As Figure 3 shown, a first device 305 (e.g., shown as a UE in example 300) may communicate with a second device 310 (e.g., shown as a base station in example 300) using one or more active beams 315. In some aspects, the first device 305 and the second device 310 may also be capable of communicating via one or more candidate beams 320. In some aspects, an active beam 315 may be selected from a set of candidate beams 320 by comparing beam parameters (e.g., RSRP, RSRQ, RSSI, etc.) of the set of candidate beams 320. For example, the active beam 315 may be the beam having the best beam parameters among all the beams in the set of candidate beams 320. In some aspects, these beams may operate in a millimeter wave radio frequency band.

[0054] In some aspects, if the active beam 315 experiences a failure, the first device 305 may execute a beam failure recovery procedure. For example, upon detecting a failure of the active beam 315, the first device 305 may attempt to communicate with the second device 310 by transmitting a beam failure recovery request (BFRQ) via one or more candidate beams 320. However, if the first device 305 and the second device 310 are communicating using carrier aggregation (where there are multiple possible cells (e.g., a primary cell, and one or more secondary cells (which may be included in one or more secondary cell groups)) via which a BFRQ may be transmitted), the complexity of the procedure increases. Some of the techniques and devices described herein assist in transmitting a beam failure recovery request via a secondary cell used for carrier aggregation.

[0055] As indicated above, Figure 3 is provided as an example. Other examples may be different from the example described with respect to Figure 3 the example.

[0056] Figure 4FIG. is a diagram illustrating example 400 of a beam failure recovery procedure in accordance with certain aspects of the present disclosure.

[0057] As Figure 4 shown, base station 110 and UE 120 may communicate with each other using carrier aggregation. By using carrier aggregation, base station 110 and UE 120 may communicate with each other using a primary cell (PCell) and one or more secondary cells (SCells). In example 400, these SCells are DL-only SCells, which means these SCells are configured for downlink communication only and are not configured for uplink communication.

[0058] As indicated by reference numeral 405, UE 120 may detect a beam failure on a DL-only SCell. As indicated by reference numeral 410, UE 120 and base station 110 may use the PCell to perform a beam failure recovery procedure. For example, UE 120 may transmit a scheduling request on the PCell via a physical uplink control channel (PUCCH). The scheduling request may trigger beam failure recovery (BFR). At least in part based on receiving the scheduling request, base station 110 may transmit a physical downlink shared channel (PDCCH) communication on the PCell, the PDCCH communication scheduling PUCCH communication for BFR.

[0059] UE 120 may receive the PDCCH communication and may transmit the scheduled PUCCH communication on the PCell. The PUCCH communication may identify the SCell that has experienced beam failure and / or may indicate a candidate beam index for a candidate beam to replace the failed beam. For example, the PUCCH communication may include a media access control (MAC) control element (CE) (collectively referred to as MAC-CE) that identifies the failed SCell and the replacement beam. At least partially based on receiving the PUCCH communication, the base station 110 may transmit on the PCell a PDCCH communication that instructs the UE 120 regarding the BFR procedure. For example, the PDCCH communication may instruct the UE 120 to perform a random access procedure for the SCell on one or more candidate beams. The UE 120 may perform BFR according to the PDCCH communication to obtain a new beam for communicating on the SCell. In some cases, one or more SCells used for carrier aggregation between the UE 120 and the base station 110 may be configured for uplink communication. In such a case, a beam failure recovery procedure for the SCell may be performed, which includes the UE 120 transmitting one or more uplink messages via the SCell or another SCell configured for the UE 120. In this way, the load on the PCell can be reduced. In addition, the UE 120 may improve reliability by increasing the transmit diversity of uplink BFR messages, such as by using multiple SCells, the PCell, and one or more SCells. However, there may be multiple options regarding which SCell (or which SCells) to use for transmitting the BFRQ, which resources of the SCell (or the SCells) to use for transmitting the BFRQ, whether to use the PCell in addition to one or more SCells for transmitting the BFRQ, and so on. Some of the techniques and devices described herein allow for identifying one or more resources and / or one or more SCells for transmitting the BFRQ. In some cases, the resources and / or SCells may be selected to reduce the ambiguity between the UE 120 and the base station 110, improve reliability, reduce latency, provide transmit diversity, balance the load across carriers, and so on.

[0060] As indicated above, Figure 4 is provided as an example. Other examples may be different from the example regarding Figure 4 described.

[0061] Figure 5 is a diagram illustrating example 500 for transmitting a beam failure recovery request via a secondary cell used for carrier aggregation in accordance with various aspects of the present disclosure.

[0062] As Figure 5As shown, UE 120 and base station 110 may communicate with each other using carrier aggregation. By using carrier aggregation, UE 120 and base station 110 may communicate with each other using a PCell and one or more SCell. In example 500, one or more of the SCell may be configured for uplink communication. In some aspects, one or more of the SCell may be configured for both uplink communication and downlink communication. In some aspects, base station 110 may configure the PCell and one or more SCell for UE 120, such as by using the configuration indicated in radio resource control (RRC) messages (e.g., RRC configuration messages, RRC reconfiguration messages, etc.).

[0063] As indicated by reference numeral 505, UE 120 may detect a beam failure on an SCell (e.g., an SCell configured for UE 120). In some aspects, the beam failure may be a complete failure of all channels (e.g., control channels, data channels, etc.) associated with UE 120 and / or the SCell. In some aspects, the beam failure is a partial failure of a channel (e.g., failure of one or more channels, failure of a subset of channels, etc.) associated with UE 120 and / or the SCell.

[0064] As indicated by reference numeral 510, UE 120 may identify one or more resources for transmitting a beam failure recovery request (BFRQ) based at least in part on detecting the beam failure. In some aspects, the one or more resources are on one or more SCell configured for UE 120 (e.g., one or more SCell supporting uplink communication). For example, UE120 may identify one or more time domain resources, one or more frequency domain resources, one or more spatial domain resources, etc. on the SCell. As shown, in addition to identifying one or more resources on the SCell for transmitting the BFRQ, UE 120 may also identify one or more resources on the PCell for transmitting the BFRQ, as described in more detail below.

[0065] The BFRQ may indicate that the beam has failed. In some aspects, the BFRQ may identify the failed beam, may identify the SCell identifier (which identifies the SCell on which the beam has failed), may identify (e.g., using a beam index) a candidate beam for replacing the failed beam, etc.

[0066] In some aspects, the UE 120 may identify a set of SCell(s) (e.g., one or more SCell(s)) on which to transmit the BFRQ. The UE 120 may then identify one or more resources for transmitting the BFRQ on each SCell included in the set of SCell(s). In some aspects, the set of SCell(s) may include all SCell(s) configured for supporting uplink communication for the UE 120. In this way, the UE 120 may use transmit diversity to improve reliability and may increase the likelihood that the base station 110 receives the BFRQ.

[0067] In some aspects, the set of SCell(s) may include a subset of all SCell(s) configured for supporting uplink communication for the UE 120. For example, the set of SCell(s) may include one or more SCell(s) configured with a PUCCH resource group for the BFRQ. For example, the base station 110 may configure the UE 120 to have a set of uplink resources (e.g., PUCCH resource group) to be used for transmitting the BFRQ. Such a set of (one or more) uplink resources may be referred to herein as a BFRQ resource set. In some aspects, the base station 110 may configure the UE 120 to have a BFRQ resource set in an RRC message. The configuration for the BFRQ resources may indicate, for example, the periodicity of the BFRQ resource set, the offset of the BFRQ resource set, etc. In some aspects, the base station 110 may configure the UE 120 to have a BFRQ resource set for a particular SCell (e.g., per-SCell BFRQ resource configuration). In such a case, some SCell(s) may be configured with BFRQ resources while some SCell(s) may not be configured with BFRQ resources. Additionally, different SCell(s) may be configured with different BFRQ resources. In some aspects, the set of SCell(s) identified by the UE 120 for transmitting the BFRQ may include all SCell(s) configured with a BFRQ resource set. Alternatively, the set of SCell(s) identified by the UE 120 for transmitting the BFRQ may include a subset of all SCell(s) configured with a BFRQ resource set. In this way, network resources may be saved compared to transmitting the BFRQ on all SCell(s), and the base station 110 may save base station resources (e.g., memory resources, processing resources, etc.) by monitoring the BFRQ on fewer SCell(s) than all SCell(s) configured for the UE 120.

[0068] In some aspects, the UE 120 may be configured with one or more SCell groups, each including a set of SCell. For example, an SCell group may include: multiple SCell included in the same frequency band (e.g., different sub-bands of the same frequency band). As another example, an SCell group may include multiple SCell having beams that are quasi-co-located with each other (e.g., each beam of each SCell in the SCell group has the same quasi-co-location (QCL) relationship). In some aspects, a single SCell in an SCell group may be designated or configured as a secondary primary cell (Spcell). In some aspects, the set of SCell identified by the UE 120 for transmitting BFRQ may include: all Spcell configured for the UE 120. Alternatively, the set of SCell identified by the UE 120 for transmitting BFRQ may include: a subset of all Spcell configured for the UE 120. In this way, network resources can be saved compared to transmitting BFRQ on all SCell, and the base station 110 can save base station resources (e.g., memory resources, processing resources, etc.) by monitoring BFRQ on fewer SCell than all SCell configured for the UE 120.

[0069] In some aspects, only a single SCell in an SCell group may be permitted to be configured with a PUCCH group for BFRQ. In other words, an SCell group may be configured with: at most one SCell configured with a PUCCH group for BFRQ. In this case, zero or one SCell in the SCell group may be configured with a PUCCH group for BFRQ. In some aspects, the SCell configured with a PUCCH group for BFRQ may be the same SCell that is the secondary primary cell of the SCell group. In some aspects, the set of SCell identified by the UE 120 for transmitting BFRQ may include: the single SCell in the SCell group configured with a PUCCH group for BFRQ. In some aspects, the set of SCell identified by the UE 120 for transmitting BFRQ may include: multiple SCell configured with a PUCCH group for BFRQ, where each of the multiple SCell is in a different SCell group.

[0070] In some aspects, the set of SCell(s) identified by the UE 120 for transmitting the BFRQ may include one or more SCell(s) in addition to the SCell(s) in which beam failure is detected. In this way, compared with transmitting the BFRQ on the SCell(s) experiencing beam failure, the UE 120 can increase the likelihood that the base station 110 receives the BFRQ. For example, the set of SCell(s) identified by the UE 120 for transmitting the BFRQ may include: one or more SCell(s) in a different SCell group (or different SCell groups) from the SCell(s) in which beam failure is detected. Since the SCell(s) in an SCell group may have beams that are quasi-co-located with each other, transmitting the BFRQ in a different SCell group can increase the likelihood that the base station 110 receives the BFRQ (e.g., reliability can be improved).

[0071] In some aspects, the set of SCell(s) identified by the UE 120 for transmitting the BFRQ may include: one or more SCell(s) in the same SCell group as the SCell(s) in which beam failure is detected. This may reduce complexity compared to using different SCell groups. However, to improve reliability, the set of SCell(s) identified by the UE 120 for transmitting the BFRQ may include: one or more SCell(s) that configure their PUCCH on a beam different from the beam of the SCell(s) in which beam failure is detected. This can avoid transmitting the BFRQ on the failed beam, thereby improving reliability.

[0072] In some aspects, the UE 120 may identify the set of SCell(s) for transmitting the BFRQ based at least in part on performing channel measurements. For example, the UE 120 may perform channel measurements on the SCell(s) configured for the UE 120 (e.g., all SCell(s) of the UE 120, all SCell(s) of the UE 120 that support uplink communication, a subset of SCell(s) of the UE 120 that meet certain conditions, etc.). The UE 120 may identify the SCell(s) with the best channel measurements (e.g., the best RSRP parameter), the SCell(s) with channel measurements that meet a threshold (e.g., an RSRP parameter that meets a threshold), etc. In this way, the UE 120 can improve the reliability for the BFRQ.

[0073] In some aspects, the UE 120 may identify a set of SCell(s) for transmitting the BFRQ based at least in part on the BFRQ resource configuration associated with each of the SCell(s). As described above, different SCell(s) may be configured with different BFRQ resources. As a result, the BFRQ resources on different SCell(s) may occur at different times. In some aspects, the UE 120 may identify the SCell(s) that have BFRQ resources that occur earlier in time or earliest in time after detecting a beam failure compared to other SCell(s) (e.g., compared to all SCell(s) of the UE 120, all SCell(s) of the UE 120 that support uplink communication, a subset of SCell(s) of the UE 120 that meet certain conditions, etc.). Additionally or alternatively, the UE 120 may identify the SCell(s) that have BFRQ resources that meet certain conditions (e.g., BFRQ resources that occur within a threshold amount of time after detecting a beam failure). In this way, the UE 120 may reduce the waiting time for the BFRQ.

[0074] In some aspects, the UE 120 may identify a set of SCell(s) for transmitting the BFRQ based at least in part on pre-specified rules (e.g., rules specified in a wireless communication standard). Additionally or alternatively, the UE 120 may identify a set of SCell(s) for transmitting the BFRQ based at least in part on rules indicated by the base station 110 (e.g., in an RRC message, a MAC-CE, etc.). In some aspects, the rule may be based at least in part on the SCell identifier. For example, the set of SCell(s) identified by the UE 120 may have SCell identifiers that are smaller (e.g., smaller index values) than other SCell(s) configured for the UE 120 (e.g., may have one or more of the smallest SCell identifiers), may have SCell identifiers that are larger (e.g., larger index values) than other SCell(s) configured for the UE 120 (e.g., may have one or more of the largest SCell identifiers), may have specific SCell identifiers indicated by the rule, etc.

[0075] In some aspects, the UE 120 may identify a set of SCell(s) for transmitting the BFRQ based at least in part on an indication from the base station 110. For example, the base station 110 may indicate to the UE 120 the set of SCell(s) to be used for transmitting the BFRQ. The indication from the base station 110 may be included in, for example, an RRC message, a MAC-CE, etc.

[0076] In some aspects, the UE 120 may identify a set of SCell(s) for transmitting the BFRQ based at least in part on one or more SCell(s) that are configured with BFRQ resources. If an SCell is not configured with BFRQ resources, the UE 120 may refrain from identifying that SCell for transmitting the BFRQ (e.g., at least for the procedure of transmitting the BFRQ using the configured BFRQ resources). Additionally or alternatively, the UE 120 may identify a set of SCell(s) for transmitting the BFRQ based at least in part on one or more SCell(s) that are configured with a contention-free random access (CFRA) resource set. If an SCell is not configured with CFRA resources, the UE 120 may refrain from identifying that SCell for transmitting the BFRQ (e.g., at least for the procedure of transmitting the BFRQ using the configured CFRA resources). Thus, the set of SCell(s) identified by the UE 120 may be configured with BFRQ resources (e.g., PUCCH groups for BFRQ), CFRA resources, etc.

[0077] In some aspects, the UE 120 may use a combination of the above techniques to identify one or more SCell(s) for transmitting the BFRQ. For example, the UE 120 may identify a first set of SCell(s) that meet a first condition among all the SCell(s) configured by the UE 120. The first condition may be used to identify, for example, a set of SCell(s) that support uplink communication, a set of SCell(s) that are configured with BFRQ resources, a set of SCell(s) that are configured with CFRA resources, a set of SCell(s) that are Spcells of an SCell group, etc. After identifying the first set of SCell(s), the UE 120 may then identify a second set of SCell(s) that meet a second condition within the first set of SCell(s). The second condition may be used to identify, for example, a set of SCell(s) within a particular SCell group (e.g., the same SCell group as or a different SCell group from a failed SCell), a set of SCell(s) associated with channel measurements that meet a condition (e.g., (the) best channel measurements), a set of SCell(s) associated with BFRQ resources that meet a condition (e.g., (the) earliest-occurring BFRQ resources), etc.

[0078] As shown by reference numeral 515, the UE 120 may use at least one or more resources on the SCell to transmit a BFRQ to the base station 110. For example, the UE 120 may identify one or more SCell(s) for transmitting the BFRQ as described above. The UE 120 may identify one or more resources of the one or more identified SCell(s). For example, the one or more resources may include one or more BFRQ resources of the one or more SCell(s) (e.g., for a procedure in which the UE 120 uses a configured BFRQ resource to transmit the BFRQ), may include one or more CFRA resources of the one or more SCell(s) (e.g., for a procedure in which the UE 120 uses a configured CFRA resource to transmit the BFRQ), and so on. The UE 120 may transmit the BFRQ on the one or more identified resources.

[0079] In some aspects, the UE 120 may transmit the BFRQ only on one or more SCell(s) and may refrain from transmitting the BFRQ on the PCell. In this way, the UE 120 may reduce the load on the PCell. Alternatively, the UE 120 may transmit the BFRQ on the PCell and on one or more SCell(s). In this way, the UE 120 may improve transmit diversity. In some aspects, if the UE 120 cannot identify any SCell(s) for transmitting the BFRQ (e.g., when none of the SCell(s) of the UE 120 is configured with a BFRQ resource and / or a CFRA resource), then the UE 120 may transmit the BFRQ on the PCell and may refrain from transmitting the BFRQ on any SCell(s).

[0080] In some aspects, the one or more resources identified by the UE 120 may include resources on multiple (different) channels. For example, the UE 120 may use a two-step BFRQ procedure to transmit the BFRQ, which may include a first transmission (e.g., a scheduling request) on a first channel (e.g., PUCCH) and a second transmission (e.g., the second transmission indicates an SCell identifier of an SCell having a failed beam, indicates a candidate beam to replace the failed beam, etc.) on a second channel (e.g., PUSCH). In some aspects, the multiple channels (e.g., the first channel and the second channel) may be on the same cell or component carrier (e.g., the same SCell). In some aspects, the multiple channels may be on different cells. For example, the first channel may be on a first SCell and the second channel may be on a second SCell. As another example, the first channel may be on an SCell and the second channel may be on the PCell. As another example, the first channel may be on the PCell and the second channel may be on an SCell.

[0081] As indicated by reference numeral 520, at least in part based on receiving a BFRQ, base station 110 may transmit a Beam Failure Recovery Response (BFRR) to UE 120. In some aspects, the BFRR is transmitted on the PCell. In some aspects, the BFRR is transmitted on one or more of the SCell(s) that UE 120 uses to transmit the BFRQ. For example, the BFRR may be transmitted on the same SCell that UE 120 uses to transmit the BFRQ. In some aspects, the BFRR may be transmitted on multiple SCell(s) (e.g., in the case where UE 120 uses multiple SCell(s) to transmit the BFRQ).

[0082] In some aspects, the BFRR includes an Acknowledgment (ACK), such as an ACK of a MAC-CE transmitted by UE 120 in a PUSCH in a two-step BFRQ procedure. In the two-step BFRQ procedure, UE 120 may transmit a MAC-CE indicating a candidate beam. In such a case, the BFRR may be an ACK of the MAC-CE and may indicate that base station 110 approves or acknowledges the indicated candidate beam for subsequent communication on the failed SCell. Alternatively, base station 110 may indicate a beam different from the beam indicated by UE 120 for the failed SCell. The two-step BFRQ procedure may be a procedure in which UE 120 uses the configured BFRQ resources to perform beam failure recovery.

[0083] In some aspects, the BFRR includes PDCCH communication, such as a PDCCH command regarding a CFRA procedure as part of a one-step BFRQ procedure. In this one-step BFRQ procedure, UE 120 notifies base station 110 of a beam failure, and the base station 110 uses PDCCH communication to instruct UE 120 to perform a CFRA procedure to identify candidate beams for the failed beam for an alternative SCell. The one-step BFRQ procedure may be a procedure in which UE 120 uses the configured CFRA resources to perform beam failure recovery.

[0084] By using one or more SCell(s) to transmit the BFRQ, UE 120 may reduce the load on the PCell, may reduce the ambiguity between UE 120 and base station 110 (e.g., by following rules or in a manner common to both UE 120 and base station 110 to identify the SCell), may improve reliability, may reduce latency, may provide transmit diversity, may balance the load across cells or carriers, etc.

[0085] As indicated above, Figure 5 is provided as an example. Other examples may be different from the example(s) described with respect to Figure 5 that are described.

[0086] Figure 6 FIG. is an illustration of an example process 600, such as may be performed by a UE, in accordance with various aspects of the present disclosure. Example process 600 is an example in which a UE (e.g., UE 120, etc.) performs operations associated with transmitting a beam failure recovery request via a secondary cell used for carrier aggregation.

[0087] As shown in Figure 6 , in some aspects, process 600 may include detecting a beam failure on an SCell, where the UE is configured with a PCell and the SCell for carrier aggregation with a base station (block 610). For example, the UE (e.g., using receive processor 258, transmit processor 264, controller / processor 280, memory 282, etc.) may detect a beam failure on the SCell, as described above. In some aspects, the UE is configured with a PCell and an SCell for carrier aggregation with a base station.

[0088] As further shown in Figure 6 , in some aspects, process 600 may include identifying one or more resources for transmitting a beam failure recovery request, at least in part based on detecting the beam failure, where the one or more resources are on one or more SCells configured for the UE (block 620). For example, the UE (e.g., using receive processor 258, transmit processor 264, controller / processor 280, memory 282, etc.) may identify one or more resources for transmitting a beam failure recovery request, at least in part based on detecting the beam failure, as described above. In some aspects, the one or more resources are on one or more SCells configured for the UE.

[0089] As further shown in Figure 6 , in some aspects, process 600 may include transmitting the beam failure recovery request to the base station using the one or more resources (block 630). For example, the UE (e.g., using transmit processor 264, controller / processor 280, memory 282, etc.) may transmit the beam failure recovery request to the base station using the one or more resources, as described above.

[0090] Process 600 may include additional aspects, such as any individual aspect or any combination of aspects described below and / or in connection with one or more other processes described elsewhere herein.

[0091] In a first aspect, the one or more SCells include all SCells configured for the UE that support uplink communication.

[0092] In a second aspect, either alone or in combination with the first aspect, the one or more SCell(s) include one or more SCell(s) configured with a physical uplink control channel resource set for the beam failure recovery request for the UE.

[0093] In a third aspect, either alone or in combination with one or more of the first and second aspects, the one or more SCell(s) include one or more secondary primary cells in one or more SCell sets configured for the UE.

[0094] In a fourth aspect, either alone or in combination with one or more of the first to third aspects, the one or more SCell(s) are in a different SCell set from the SCell in which the beam failure is detected.

[0095] In a fifth aspect, either alone or in combination with one or more of the first to fourth aspects, the one or more SCell(s) are in the same SCell set as the SCell in which the beam failure is detected.

[0096] In a sixth aspect, either alone or in combination with one or more of the first to fifth aspects, the one or more SCell(s) have corresponding physical uplink control channels configured on beams different from the beam of the SCell in which the beam failure is detected.

[0097] In a seventh aspect, either alone or in combination with one or more of the first to sixth aspects, the one or more SCell(s) are identified at least in part based on channel measurements performed by the UE.

[0098] In an eighth aspect, either alone or in combination with one or more of the first to seventh aspects, the one or more SCell(s) are associated with channel measurements that meet a condition or threshold.

[0099] In a ninth aspect, either alone or in combination with one or more of the first to eighth aspects, the one or more SCell(s) are associated with a beam failure recovery request resource that occurs earlier in time than the beam failure recovery request resources configured for one or more other SCell(s) of the UE.

[0100] In a tenth aspect, either alone or in combination with one or more of the first to ninth aspects, the one or more SCell(s) are associated with a beam failure recovery request resource that is the earliest to occur in time after the beam failure is detected compared to the beam failure recovery request resources configured for all other SCell(s) of the UE.

[0101] In an eleventh aspect, either alone or in combination with one or more of the first to tenth aspects, the one or more SCell(s) are configured with at least one of the following: a physical uplink control channel resource set for the beam failure recovery request, contention-free random access resources, or a combination thereof.

[0102] In a twelfth aspect, either alone or in combination with one or more of the first to eleventh aspects, process 600 includes: transmitting the beam failure recovery request on the PCell.

[0103] In a thirteenth aspect, either alone or in combination with one or more of the first to twelfth aspects, the one or more SCell(s) on which the beam failure recovery request is to be transmitted are identified at least in part based on the respective SCell identifier(s) of the one or more SCell(s).

[0104] In a fourteenth aspect, either alone or in combination with one or more of the first to thirteenth aspects, the one or more SCell(s) on which the beam failure recovery request is to be transmitted are indicated by the base station in a radio resource control message, a media access control (MAC) control element, or a combination thereof.

[0105] In a fifteenth aspect, either alone or in combination with one or more of the first to fourteenth aspects, the beam failure recovery request is transmitted using multiple channels, and the multiple channels are on different cells.

[0106] In a sixteenth aspect, either alone or in combination with one or more of the first to fifteenth aspects, the beam failure recovery response is received on the PCell.

[0107] In a seventeenth aspect, either alone or in combination with one or more of the first to sixteenth aspects, the beam failure recovery request is received on at least one of the one or more SCell(s).

[0108] Although Figure 6 illustrates example blocks of process 600, in some aspects, process 600 may include additional blocks, fewer blocks, different blocks, or differently arranged blocks compared to the blocks depicted in Figure 6 . Additionally or alternatively, two or more blocks of process 600 may be executed in parallel.

[0109] Figure 7 is a diagram illustrating an example process 700, such as performed by a base station, in accordance with various aspects of the present disclosure. Example process 700 is an example in which a base station (e.g., base station 110, etc.) performs operations associated with transmitting a beam failure recovery request via a secondary cell used for carrier aggregation.

[0110] As shown in Figure 7 In some aspects, process 700 may include communicating with a UE using a PCell and an SCell for carrier aggregation (block 710). For example, the base station (e.g., using the transmit processor 220, the receive processor 238, the controller / processor 240, the memory 242, etc.) may communicate with the UE using a PCell and an SCell for carrier aggregation, as described above.

[0111] As Figure 7 further shown in, in some aspects, process 700 may include receiving, from the UE, a beam failure recovery request for the SCell, where the beam failure recovery request is received on one or more resources configured for one or more SCells of the UE (block 720). For example, the base station (e.g., using the receive processor 238, the controller / processor 240, the memory 242, etc.) may receive, from the UE, a beam failure recovery request for the SCell, as described above. In some aspects, the beam failure recovery request is received on one or more resources configured for one or more SCells of the UE.

[0112] As Figure 7 further shown in, in some aspects, process 700 may include transmitting a beam failure recovery response to the UE, at least in part based on receiving the beam failure recovery request (block 730). For example, the base station (e.g., using the transmit processor 220, the controller / processor 240, the memory 242, etc.) may transmit a beam failure recovery response to the UE, at least in part based on receiving the beam failure recovery request, as described above.

[0113] Process 700 may include additional aspects, such as any individual aspect or any combination of aspects described below and / or in combination with one or more other processes described elsewhere herein.

[0114] In a first aspect, the one or more SCells include all SCells configured for the UE to support uplink communication.

[0115] In a second aspect, individually or in combination with the first aspect, the one or more SCells include one or more SCells configured for the UE and configured with a physical uplink control channel resource group for the beam failure recovery request.

[0116] In a third aspect, individually or in combination with one or more of the first and second aspects, the one or more SCells include one or more secondary primary cells in one or more SCell groups configured for the UE.

[0117] In a fourth aspect, either alone or in combination with one or more of the first to third aspects, the one or more SCell(s) are in a different SCell group from the SCell in which the beam failure is detected.

[0118] In a fifth aspect, either alone or in combination with one or more of the first to fourth aspects, the one or more SCell(s) are in the same SCell group as the SCell in which the beam failure is detected.

[0119] In a sixth aspect, either alone or in combination with one or more of the first to fifth aspects, the one or more SCell(s) have corresponding physical uplink control channels configured on beams different from the beam of the SCell in which the beam failure is detected.

[0120] In a seventh aspect, either alone or in combination with one or more of the first to sixth aspects, the one or more SCell(s) are associated with beam failure recovery request resources that occur earlier in time than the beam failure recovery request resources configured for one or more other SCell(s) of the UE.

[0121] In an eighth aspect, either alone or in combination with one or more of the first to seventh aspects, the one or more SCell(s) are associated with beam failure recovery request resources that occur earliest in time after the detection of the beam failure compared to the beam failure recovery request resources configured for all other SCell(s) of the UE.

[0122] In a ninth aspect, either alone or in combination with one or more of the first to eighth aspects, the one or more SCell(s) are configured with at least one of the following: a physical uplink control channel resource set for the beam failure recovery request, contention-free random access resources, or a combination thereof.

[0123] In a tenth aspect, either alone or in combination with one or more of the first to ninth aspects, process 700 includes: receiving the beam failure recovery request on the PCell.

[0124] In an eleventh aspect, either alone or in combination with one or more of the first to tenth aspects, the one or more SCell(s) are at least partially identified based on the respective SCell identifiers of the one or more SCell(s).

[0125] In a twelfth aspect, either alone or in combination with one or more of the first to eleventh aspects, process 700 includes: indicating the one or more SCell(s) to the UE in a radio resource control message, a media access control (MAC) control element, or a combination thereof.

[0126] In a thirteenth aspect, either alone or in combination with one or more of the first to twelfth aspects, the beam failure recovery request is received using multiple channels, and the multiple channels are on different cells.

[0127] In a fourteenth aspect, either alone or in combination with one or more of the first to thirteenth aspects, the beam failure recovery response is transmitted on the PCell.

[0128] In a fifteenth aspect, either alone or in combination with one or more of the first to fourteenth aspects, the beam failure recovery request is transmitted on at least one of the one or more SCell(s).

[0129] In a sixteenth aspect, either alone or in combination with one or more of the first to fifteenth aspects, only a single SCell in an SCell group is permitted to be configured with a physical uplink control channel resource group for the beam failure recovery request, and the one or more SCell(s) include the single SCell.

[0130] Although Figure 7 example blocks of process 700 are shown, in some aspects, process 700 may include additional blocks, fewer blocks, different blocks, or blocks arranged differently compared to those depicted in Figure 7 . Additionally or alternatively, two or more blocks of process 700 may be executed in parallel.

[0131] The foregoing disclosure provides illustration and description, but is not intended to be exhaustive or to limit the aspects to the precise forms disclosed. Modifications and variations may be made in light of the above disclosure or may be obtained by practicing the aspects.

[0132] As used herein, the term "component" is intended to be broadly interpreted as hardware, firmware, and / or a combination of hardware and software. As used herein, a processor is implemented with hardware, firmware, and / or a combination of hardware and software.

[0133] As used herein, depending on the context, meeting a threshold may mean that a value is greater than the threshold, greater than or equal to the threshold, less than the threshold, less than or equal to the threshold, equal to the threshold, not equal to the threshold, etc.

[0134] It will be apparent that the systems and / or methods described herein may be implemented in different forms of hardware, firmware, and / or a combination of hardware and software. The actual specific control hardware or software code used to implement these systems and / or methods does not limit the aspects. Accordingly, the operation and behavior of these systems and / or methods are described herein without reference to specific software code—understanding that software and hardware can be designed to implement these systems and / or methods at least in part based on the description herein.

[0135] Although specific feature combinations are recited in the claims and / or disclosed in the specification, these combinations are not intended to limit the disclosure of the various aspects. In fact, many of these features may be combined in ways not specifically recited in the claims and / or not disclosed in the specification. Although each of the dependent claims listed below may directly depend on only one claim, the disclosure of the various aspects includes each dependent claim in combination with each other claim in this set of claims. A phrase that recites "at least one" of a list of items refers to any combination of those items, including a single member. By way of example, "at least one of a, b, or c" is intended to cover: a, b, c, a - b, a - c, b - c, and a - b - c, as well as any combination having multiple identical elements (e.g., a - a, a - a - a, a - a - b, a - a - c, a - b - b, a - c - c, b - b, b - b - b, b - b - c, c - c, and c - c - c, or any other ordering of a, b, and c).

[0136] Elements, acts, or instructions used herein should not be construed as critical or essential unless expressly described as such. Also, as used herein, the articles "a" and "an" are intended to include one or more items and may be used interchangeably with "one or more." Additionally, as used herein, the terms "set" and "group" are intended to include one or more items (e.g., related items, unrelated items, combinations of related and unrelated items, etc.) and may be used interchangeably with "one or more." Where only one item is intended, the phrase "only one" or similar language is used. Also, as used herein, the terms "having," "containing," "including," etc. are intended to be open - ended terms. Additionally, the phrase "based on" is intended to mean "at least partially based on" unless otherwise expressly stated.

Claims

1. A wireless communication method performed by a user equipment UE, comprising: Detecting a beam failure on a secondary cell SCell, wherein the UE is configured with a primary cell PCell for carrier aggregation with a network entity and the SCell; Identifying, at least in part based on detecting the beam failure, a plurality of resources for transmitting a plurality of beam failure recovery requests, wherein the plurality of resources are on a plurality of SCell configured for the UE, wherein the plurality of SCell on which the plurality of beam failure recovery requests are to be transmitted are indicated by a rule that indicates the plurality of SCell are identified at least in part based on: The plurality of SCell are associated with channel measurement conditions that meet a condition or threshold, and wherein the plurality of SCell include all SCell configured for the UE that meet the condition or the threshold; and Using the plurality of resources to transmit the beam failure recovery request to the network entity.

2. The method according to claim 1, wherein the plurality of SCell are configured with at least one of the following: a physical uplink control channel resource set for beam failure recovery requests, contention-free random access resources, or a combination thereof.

3. The method according to claim 1, wherein the plurality of SCell include one or more SCell configured for the UE that are configured with a physical uplink control channel resource set for beam failure recovery requests.

4. The method according to claim 1, wherein only a single SCell in a group of SCell is permitted to be configured with a physical uplink control channel resource set for beam failure recovery requests, and wherein the plurality of SCell include the single SCell.

5. The method according to claim 1, wherein the plurality of SCell includes: One or more secondary primary cells in one or more groups of SCell configured for the UE.

6. The method according to claim 1, further comprising: Transmitting another beam failure recovery request on the PCell.

7. The method according to claim 1, wherein the plurality of SCell are in the same SCell group as the SCell on which the beam failure is detected.

8. The method according to claim 1, wherein the plurality of SCell are in a different SCell group from the SCell on which the beam failure is detected.

9. The method according to claim 1, wherein the condition is met by the plurality of SCell that support uplink communication.

10. The method according to claim 1, wherein the plurality of SCell have respective physical uplink control channels configured on beams different from the beam of the SCell on which the beam failure is detected.

11. The method according to claim 1, wherein the channel measurements associated with the channel measurement conditions are performed by the UE.

12. The method according to claim 1, wherein the plurality of SCell are associated with beam failure recovery request resources that occur earlier in time than beam failure recovery request resources configured for one or more other SCell of the UE.

13. The method according to claim 1, wherein one of the plurality of SCell is associated with a beam failure recovery request resource that is earliest in time after the beam failure is detected compared to the beam failure recovery request resources for all other SCell configured for the UE.

14. The method according to claim 1, wherein at least one of the beam failure recovery requests is transmitted using a plurality of channels, and the plurality of channels are on different cells.

15. The method according to claim 1, further comprising: Receive a beam failure recovery response from the network entity, wherein the beam failure recovery response is received on the PCell.

16. The method according to claim 1, further comprising: Receive a beam failure recovery response from the network entity, wherein the beam failure recovery response is received on at least one SCell of the plurality of SCell.

17. A wireless communication method performed by a network entity, comprising: Communicating with a user equipment UE using a primary cell PCell and secondary cells SCell for carrier aggregation; Instructing the UE a rule that indicates that the plurality of SCell to be used for transmitting a plurality of beam failure recovery requests is at least partially based on: The plurality of SCell are associated with channel measurement conditions that meet a condition or threshold; Receiving from the UE the beam failure recovery requests for the plurality of SCell, wherein the beam failure recovery requests are received on all SCell configured for the UE that meet the condition or the threshold; And Transmitting a beam failure recovery response to the UE at least partially based on receiving the beam failure recovery requests.

18. The method according to claim 17, wherein the plurality of SCell includes one or more SCell configured for the UE that are configured with a physical uplink control channel resource set for the beam failure recovery request.

19. The method according to claim 17, wherein the plurality of SCell are configured with at least one of the following: a physical uplink control channel resource set for a beam failure recovery request, contention-free random access resources, or a combination thereof.

20. The method according to claim 17, wherein only a single SCell in a group of SCell is permitted to be configured with a physical uplink control channel resource set for a beam failure recovery request, and wherein the plurality of SCell includes the single SCell.

21. The method according to claim 17, wherein the plurality of SCell includes one or more secondary primary cells in one or more groups of SCell configured for the UE.

22. The method according to claim 17, further comprising: Receive another beam failure recovery request on the PCell.

23. The method according to claim 17, wherein the beam failure recovery response is transmitted to the UE using the PCell.

24. A user equipment UE for wireless communication, comprising: A memory; And One or more processors operatively coupled to the memory, the one or more processors being configured to cause the UE: Detect beam failures on a secondary cell (SCell), where the UE is configured with a primary cell (PCell) for carrier aggregation with a network entity and the SCell; Identify, at least in part based on detecting the beam failure, a plurality of resources for transmitting a plurality of beam failure recovery requests, where the plurality of resources are on a plurality of SCells configured for the UE; where the plurality of SCells on which to transmit the plurality of beam failure recovery requests are indicated by a rule that indicates the plurality of SCells are identified at least in part based on: the plurality of SCells are associated with channel measurement conditions that meet a condition or threshold, and where the plurality of SCells include all SCells configured for the UE that meet the condition or the threshold; and Use the plurality of resources to transmit the beam failure recovery requests to the network entity.

25. The UE of claim 24, wherein the plurality of SCells are configured with at least one of: a physical uplink control channel resource set for beam failure recovery requests, contention-free random access resources, or a combination thereof.

26. The UE of claim 24, wherein the plurality of SCells include one or more SCells configured for the UE that are configured with a physical uplink control channel resource set for beam failure recovery requests.

27. The UE of claim 24, wherein only a single SCell in an SCell set is permitted to be configured with a physical uplink control channel resource set for beam failure recovery requests, and wherein the plurality of SCells include the single SCell.

28. The UE according to claim 24, wherein the plurality of SCell includes: One or more secondary primary cells in one or more SCell sets configured for the UE.

29. The UE of claim 24, wherein the one or more processors are further configured to cause the UE to transmit another beam failure recovery request on the PCell.

30. The UE of claim 24, wherein the plurality of SCells are in the same SCell set as the SCell on which the beam failure was detected.

31. The UE of claim 24, wherein the plurality of SCells are in a different SCell set from the SCell on which the beam failure was detected.

32. The UE of claim 24, wherein the condition is met by the plurality of SCells that support uplink communication.

33. The UE of claim 24, wherein the plurality of SCells have respective physical uplink control channels configured on beams different from the beam of the SCell on which the beam failure was detected.

34. The UE of claim 24, wherein the channel measurements associated with the channel measurement conditions are performed by the UE.

35. The UE according to claim 24, wherein the plurality of SCell are associated with beam failure recovery request resources that occur earlier in time than beam failure recovery request resources configured for one or more other SCell of the UE.

36. The UE according to claim 24, wherein one of the plurality of SCell is associated with beam failure recovery request resources that occur earliest in time after detection of the beam failure compared to beam failure recovery request resources configured for all other SCell of the UE.

37. The UE according to claim 24, wherein at least one of the beam failure recovery requests is transmitted using a plurality of channels, and the plurality of channels are on different cells.

38. The UE according to claim 24, wherein the one or more processors are further configured to cause the UE to receive a beam failure recovery response from the network entity, wherein the beam failure recovery response is received on the PCell.

39. The UE according to claim 24, wherein the one or more processors are further configured to cause the UE to receive a beam failure recovery response from the network entity, wherein the beam failure recovery response is received on at least one SCell of the plurality of SCell.

40. A network entity for wireless communication, comprising: a memory; and one or more processors operatively coupled to the memory, the one or more processors being configured to cause the network entity to: communicate with a user equipment UE using a primary cell PCell and secondary cells SCell for carrier aggregation; indicate to the UE a rule that indicates that a plurality of SCell to be used for transmitting a plurality of beam failure recovery requests are at least partially based on: the plurality of SCell being associated with channel measurement conditions that meet a condition or threshold; receive from the UE the beam failure recovery requests for the plurality of SCell, wherein the beam failure recovery requests are received on all SCell of the UE that meet the condition or the threshold; and transmit a beam failure recovery response to the UE at least partially based on receiving the beam failure recovery requests.

41. The network entity according to claim 40, wherein the plurality of SCell include one or more SCell configured for the UE with a physical uplink control channel resource set for the beam failure recovery requests.

42. The network entity according to claim 40, wherein the plurality of SCell are configured with at least one of: a physical uplink control channel resource set for beam failure recovery requests, contention-free random access resources, or a combination thereof.

43. The network entity according to claim 40, wherein only a single SCell in an SCell group is permitted to be configured with a physical uplink control channel resource group for beam failure recovery requests, and wherein the plurality of SCell includes the single SCell.

44. The network entity according to claim 40, wherein the plurality of SCell includes one or more secondary primary cells in one or more SCell groups configured for the UE.

45. The network entity according to claim 40, wherein the one or more processors are further configured to: Receive another beam failure recovery request on the PCell.

46. The network entity according to claim 40, wherein the beam failure recovery response is transmitted to the UE using the PCell.

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