Beam failure recovery response

Abstract

Certain aspects of the present disclosure provide techniques for managing beam failure recovery operations. A method that may be performed by a user equipment (UE) generally includes: performing beam failure detection (BFD) on a beam pair link (BPL) associated with a secondary cell (Scell) of a base station (BS); sending a beam failure recovery request (BFRQ) message in another cell of the BS, the BFRQ message including an indication of a candidate recovery beam for the Scell; and starting a timer based on sending the BFRQ.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Application No. 17 / 067,242, filed on October 9, 2020, which claims the benefit of and priority to U.S. Provisional Application No. 62 / 914,398, filed on October 11, 2019, which are hereby assigned to the assignee of the present application and are hereby expressly incorporated herein by reference in their entireties as if fully set forth below and for all applicable purposes. Technical Field

[0003] Aspects of the present disclosure relate to wireless communications and, more particularly, to techniques for managing beam failure recovery operations. Background Art

[0004] Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcast. These wireless communication systems may employ multiple-access technologies capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power, etc.). Examples of such multiple-access systems include 3rd 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 (SCFDMA) systems, and Time Division Synchronous Code Division Multiple Access (TD-SCDMA) systems, to name a few.

[0005] These multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate at municipal, national, regional, and even global levels. New radio (e.g., 5G NR) is an example of an emerging telecommunication standard. NR is a set of enhancements to 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, utilizing new spectrum, and better integrating with other open standards using OFDMA with cyclic prefix (CP) on the downlink (DL) and uplink (UL). To this end, NR supports beamforming, multiple-input multiple-output (MIMO) antenna technology, and carrier aggregation (CA).

[0006] However, as demand for mobile broadband access continues to increase, further improvements in NR and LTE technologies are needed. Preferably, these improvements should also apply to other multiple access technologies and the telecommunication standards that employ them. Summary of the Invention

[0007] The systems, methods, and apparatus of the present disclosure each have several aspects, no single one of which is solely responsible for its desirable attributes. Without limiting the scope of the disclosure as expressed by the appended claims, some features will now be briefly discussed. After considering this discussion, and particularly after reading the section entitled "Detailed Description," one will understand how the features of the present disclosure provide advantages, including improved beam fault detection.

[0008] Certain aspects relate to a method for wireless communication by a user equipment (UE). The method includes performing beam failure detection (BFD) of a beam pair link (BPL) associated with a secondary cell (Scell) of a base station (BS); transmitting a beam failure recovery request (BFRQ) message in another cell of the BS, the BFRQ message including an indication of a candidate recovery beam for the Scell; starting a timer based on transmitting the BFRQ; determining whether to resend the BFRQ message in the other cell based on whether a beam failure recovery response (BFRR) message is received in the other cell before expiration of the timer; and resending the BFRQ message in the other cell based on the determination, wherein the BFRR message includes one or more of the following types: a new transmission configuration indicator (TCI) state activation or reconfiguration for the Scell, a transmission using the candidate recovery beam for the Scell, or a deactivation command for the Scell.

[0009] Certain aspects relate to a method for wireless communications by a base station (BS). A method includes receiving a beam failure recovery request (BFRQ) message from a user equipment (UE) in a cell, the BFRQ message including an indication of a candidate recovery beam for a secondary cell (Scell) of the UE; and sending a beam failure recovery response (BFRR) message to the UE in response to the BFRQ message, the BFRR message including one or more of the following types: activation or reconfiguration of a new transmission configuration indicator (TCI) state for the Scell, transmission using the candidate recovery beam for the Scell, or a deactivation command for the Scell.

[0010] Certain aspects relate to a user equipment (UE) comprising a memory and a processor communicatively coupled to the memory. The processor is configured to perform beam failure detection (BFD) of a beam pair link (BPL) associated with a secondary cell (Scell) of a base station (BS). The processor is configured to send a beam failure recovery request (BFRQ) message in another cell of the BS, the BFRQ message including an indication of a candidate recovery beam for the Scell. The processor is configured to start a timer based on sending the BFRQ. The processor is configured to determine whether to resend the BFRQ message in the other cell based on whether a beam failure recovery response (BFRR) message is received in the other cell before the timer expires. The processor is configured to resend the BFRQ message in the other cell based on the determination, wherein the BFRR message includes one or more of the following types: a new transmission configuration indicator (TCI) state activation or reconfiguration for the Scell, a transmission using a candidate recovery beam for the Scell, or a deactivation command for the Scell.

[0011] Certain aspects relate to a base station (BS) comprising a memory and a processor communicatively coupled to the memory. The processor is configured to receive a beam failure recovery request (BFRQ) message from a user equipment (UE) in a cell, the BFRQ message including an indication of a candidate recovery beam for a secondary cell (Scell) of the UE. The processor is configured to send a beam failure recovery response (BFRR) message to the UE in response to the BFRQ message, wherein the BFRR message includes one or more of the following types: activation or reconfiguration of a new transmission configuration indicator (TCI) state for the Scell; transmission using the candidate recovery beam for the Scell; or a deactivation command for the Scell.

[0012] Certain aspects relate to a user equipment (UE). The UE includes means for performing beam failure detection (BFD) for a beam pair link (BPL) associated with a secondary cell (Scell) of a base station (BS). The UE includes means for sending a beam failure recovery request (BFRQ) message in another cell of the BS, the BFRQ message including an indication of a candidate recovery beam for the Scell. The UE includes means for starting a timer based on sending the BFRQ. The UE includes means for determining whether to resend the BFRQ message in the other cell based on whether a beam failure recovery response (BFRR) message is received in the other cell before expiration of the timer. The UE includes means for resending the BFRQ message in the other cell based on the determination, wherein the BFRR message includes one or more of the following types: a new transmission configuration indicator (TCI) state activation or reconfiguration for the Scell; a transmission using the candidate recovery beam for the Scell; or a deactivation command for the Scell.

[0013] Certain aspects relate to a base station (BS). The BS includes means for receiving a beam failure recovery request (BFRQ) message in a cell from a user equipment (UE), the BFRQ message including an indication of a candidate recovery beam for a secondary cell (Scell) of the UE. The BS includes means for sending a beam failure recovery response (BFRR) message to the UE in response to the BFRQ message, wherein the BFRR message includes one or more of the following types: a new transmission configuration indicator (TCI) state activation or reconfiguration for the Scell; a transmission using a candidate recovery beam for the Scell; or a deactivation command for the Scell.

[0014] Certain aspects relate to a non-transitory computer-readable storage medium having stored thereon instructions for wireless communication by a user equipment (UE). The instructions are configured to perform beam failure detection (BFD) of a beam pair link (BPL) associated with a secondary cell (Scell) of a base station (BS). The instructions are configured to send a beam failure recovery request (BFRQ) message in another cell of the BS, the BFRQ message including an indication of a candidate recovery beam for the Scell. The instructions are configured to start a timer based on sending the BFRQ. The instructions are configured to determine whether to resend the BFRQ message in the other cell based on whether a beam failure recovery response (BFRR) message is received in the other cell before the timer expires. The instructions are configured to resend the BFRQ message in the other cell based on the determination, wherein the BFRR message includes one or more of the following types: a new transmission configuration indicator (TCI) state activation or reconfiguration for the Scell; a transmission using a candidate recovery beam for the Scell; or a deactivation command for the Scell.

[0015] Certain aspects relate to a non-transitory computer-readable storage medium having stored thereon instructions for wireless communication by a base station (BS). The instructions are configured to receive a beam failure recovery request (BFRQ) message from a user equipment (UE) in a cell, the BFRQ message including an indication of a candidate recovery beam for a secondary cell (Scell) of the UE. The instructions are configured to send a beam failure recovery response (BFRR) message to the UE in response to the BFRQ message, wherein the BFRR message includes one or more of the following types: activation or reconfiguration of a new transmission configuration indicator (TCI) state for the Scell; transmission using a candidate recovery beam for the Scell; or a deactivation command for the Scell.

[0016] Aspects of the present disclosure provide means for apparatus, processors, and computer-readable media to perform the methods described herein.

[0017] To accomplish the foregoing and related ends, one or more aspects include the features hereinafter fully described and particularly pointed out in the claims. The following description and the accompanying drawings set forth in detail certain illustrative features of these one or more aspects. However, these features are indicative of but some of the various ways in which the principles of the various aspects may be employed. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order that the above-described features of the present disclosure may be understood in detail, a more particular description of the content briefly summarized above may be made with reference to various aspects, some of which are illustrated in the accompanying drawings. It should be noted, however, that the accompanying drawings illustrate only certain typical aspects of the present disclosure and are not to be considered limiting of its scope, as the description may admit to other equally effective aspects.

[0019] Figure 1 is a block diagram conceptually illustrating an example telecommunications system in accordance with certain aspects of the present disclosure.

[0020] Figure 2 is a block diagram conceptually illustrating designs of an exemplary base station (BS) and user equipment (UE), in accordance with certain aspects of the present disclosure.

[0021] Figure 3 is an example beam failure detection and recovery process according to certain aspects of the present disclosure.

[0022] Figure 4 is a flow chart illustrating example operations for wireless communications by a UE in accordance with certain aspects of the present disclosure.

[0023] Figure 5 is a flow chart illustrating example operations for wireless communications by a UE in accordance with certain aspects of the present disclosure.

[0024] Figure 6 Illustrated are communications devices that may include various components configured to perform operations for the techniques disclosed herein in accordance with aspects of the present disclosure.

[0025] Figure 7 Illustrated are communications devices that may include various components configured to perform operations for the techniques disclosed herein in accordance with aspects of the present disclosure.

[0026] To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements disclosed in one aspect may be beneficially utilized on other aspects without specific recitation. DETAILED DESCRIPTION

[0027] Various aspects of the present disclosure provide apparatus, methods, processing systems, and computer-readable media for managing beam failure detection. In certain wireless communication systems (e.g., 5G NR), a user equipment (UE) can communicate with a base station (BS) via multiple cells (e.g., a primary cell (Pcell) using a primary component carrier (PCC) and at least one secondary cell (Scell) using a secondary component carrier (SCC)) using carrier aggregation (CA) of a primary component carrier (PCC) and a secondary component carrier (SCC). That is, multiple cells are aggregated together to allow the BS to serve the UE. Typically, the Pcell can perform a random access (RA) procedure, a radio link monitoring (RLM), a handover procedure, and the like. In some examples, the Scell ​​can provide only a downlink, or both a downlink and an uplink. The BS can perform activation and deactivation of the Scell ​​through MAC signaling with the UE. By using MAC signaling, the BS can change the activation / deactivation state of the Scell ​​according to data activity.

[0028] Various aspects of the present disclosure relate to beam failure detection and recovery. In some systems, narrow beam transmission and reception are useful for improving link budget at 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 scenario where the quality of the beam drops below a threshold (for example, the reference signal received power (RSRP) of the BPL drops below a threshold), which may lead to a radio link failure (RLF). NR supports lower layer signaling to recover from beam failure, called beam recovery. For example, instead of initiating cell reselection when the beam quality becomes too low, intra-cell beam pair reselection can be performed. In some examples, the UE can detect a beam failure and send a beam failure recovery request (BFRQ) to the base station.

[0029] In certain aspects, the beam failure recovery (BFR) process can be cell-specific (e.g., a BFR process associated with a PCell and a BFR associated with an Scell). In one example, the UE can communicate the BFRQ intended for the Scell ​​by sending the BFRQ as a dedicated scheduling request to the PCell via the PUCCH. For example, the base station's beam failure recovery response (BFRR) to the UE's BFRQ can include an uplink grant to schedule a new transmission for hybrid automatic repeat request (HARQ).

[0030] The following description provides examples of beam failure detection and response in a communication system and does not limit the scope, applicability, or examples set forth in the claims. The functions and arrangements of the elements discussed may be modified without departing from the scope of the present disclosure. Various examples may omit, substitute, or add various processes or components as appropriate. For example, the methods described may be performed in an order different from that described, and various steps may be added, omitted, or combined. Furthermore, features described with respect to some examples may be combined in some other examples. For example, an apparatus may be implemented or a method may be practiced using any number of the aspects set forth herein. Furthermore, the scope of the present disclosure is intended to cover such apparatus or methods practiced using other structures, functionalities, or structures and functionalities in addition to or in addition to the various aspects of the disclosure set forth herein. It should be understood that any aspect of the disclosure disclosed herein may be embodied by one or more elements of the claims. The word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any aspect described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other aspects.

[0031] In general, any number of wireless networks can be deployed in a given geographic area. Each wireless network can support a specific radio access technology (RAT) and can operate on one or more frequencies. RAT can also be referred to as radio technology, air interface, etc. Frequency can also be referred to as carrier, subcarrier, frequency channel, frequency tone, subband, etc. Each frequency can support a single RAT in a given geographic area to avoid interference between wireless networks of different RATs. In some cases, 5G NR RAT networks can be deployed.

[0032] Figure 1 An exemplary wireless communication network 100 is illustrated in which various aspects of the present disclosure may be performed. For example, the wireless communication network 100 may be an NR system (e.g., a 5G NR network).

[0033] like Figure 1As shown, BS 110a includes a beam failure manager 112 configured to receive a beam failure recovery request (BFRQ) message from a user equipment (UE) in a cell, the BFRQ message including an indication of a candidate recovery beam for a secondary cell (Scell) of the UE. The beam failure manager 112 may also be configured to send a beam failure recovery response (BFRR) message to the UE in response to the BFRQ message, wherein the BFRR message includes one or more of the following types: activation or reconfiguration of a new transmission configuration indicator (TCI) state for the Scell, transmission using a candidate recovery beam for the Scell, or a deactivation command for the Scell.

[0034] UE 120a includes a beam failure manager 122 configured to perform beam failure detection (BFD) of a beam pair link (BPL) associated with a secondary cell (Scell) of a base station (BS) (e.g., in carrier aggregation). Beam failure manager 122 may also be configured to send a beam failure recovery request (BFRQ) message in another cell, the BFRQ message including an indication of a candidate recovery beam for the Scell. Beam failure manager 122 may also be configured to start a timer based on sending the BFRQ. Beam failure manager 122 may also be configured to determine whether to resend a beam failure recovery response (BFRR) message in another cell based on whether the BFRQ message is received in the other cell before the timer expires. The beam failure manager 122 may also be configured to resend the BFRQ message in another cell based on the determination, wherein the BFRR message includes one or more of the following types: new transmission configuration indicator (TCI) state activation or reconfiguration for the Scell, transmission using a candidate recovery beam for the Scell, or a deactivation command for the Scell.

[0035] NR access (e.g., 5G NR) can support various wireless communication services, such as enhanced mobile broadband (eMMB) targeting wide bandwidth (e.g., 80 MHz or higher), millimeter wave (mmWave) targeting high carrier frequency (e.g., 25 GHz or higher), massive machine type communication MTC (mMTC) targeting non-backward compatible MTC technology, and / or mission-critical services targeting 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.

[0036] like Figure 1As shown, the wireless communication network 100 may include a plurality of base stations (BSs) 110a-z (each BS also individually referred to herein as BS 110 or collectively referred to herein as BS 110) and other network entities. BS 110 may provide communication coverage for a particular geographic area, sometimes referred to as a "cell," which may be fixed or may be mobile depending on the location of mobile BS 110. In some examples, BS 110 may be interconnected to each other and / or to one or more other BSs or network nodes (not shown) in the wireless communication network 100 via various types of backhaul interfaces (e.g., direct physical connections, wireless connections, virtual networks, etc.) using any suitable transport network. Figure 1 In the illustrated example, BSs 110a, 110b, and 110c may be macro BSs for macro cells 102a, 102b, and 102c, respectively. BS 110x may be a pico BS for pico cell 102x. BSs 110y and 110z may be femto BSs for femto cells 102y and 102z, respectively. A BS may support one or more cells. BS 110 communicates with user equipment (UEs) 120a-y (each UE also referred to herein individually or collectively as UEs 120) in wireless communication network 100. UEs 120 (e.g., 120x, 120y, etc.) may be dispersed throughout wireless communication network 100, and each UE 120 may be stationary or mobile.

[0037] The wireless communication network 100 may also include a relay station (e.g., relay station 110r), also known as a relay, etc., which receives transmissions of data and / or other information from an upstream station (e.g., BS 110a or UE 120r) and sends transmissions of data and / or other information to a downstream station (e.g., UE 120 or BS 110), or relays transmissions between UEs 120 to facilitate communication between devices.

[0038] A network controller 130 may couple to a set of BSs 110 and provide coordination and control for these BSs 110. The network controller 130 may communicate with the BSs 110 via a backhaul. The BSs 110 may also communicate with each other, directly or indirectly, eg, via a wireless or wired backhaul.

[0039] Figure 2 1 illustrates a BS 110a and a UE 120a (e.g., in FIG. Figure 1 Example components of the wireless communication network 100).

[0040] At BS 110a, a transmit processor 220 may receive data from a data source 212 and control information from a controller / processor 240. 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 220 may process (e.g., encode and symbol map) the data and control information to obtain data symbols and control symbols, respectively. The transmit processor 220 may also generate reference symbols, such as for a primary synchronization signal (PSS), a secondary synchronization signal (SSS), and a PBCH demodulation reference signal (DMRS). A transmit (TX) multiple-input multiple-output (MIMO) processor 230 may perform spatial processing (e.g., precoding) on ​​the data symbols, control symbols, and / or reference symbols (if applicable), and may provide output symbol streams to the modulators (MODs) in transceivers 232a-232t. Each modulator in transceivers 232a-232t can process a corresponding 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 the modulators in transceivers 232a-232t can be transmitted via antennas 234a-234t, respectively.

[0041] At UE 120a, antennas 252a-252r may receive downlink signals from BS 110a and may provide received signals to demodulators (DEMODs) in transceivers 254a-254r, respectively. Each demodulator in transceivers 254a-254r may condition (e.g., filter, amplify, downconvert, and digitize) a corresponding received signal to obtain input samples. Each demodulator may further process the input samples (e.g., for OFDM, etc.) to obtain received symbols. A MIMO detector 256 may obtain received symbols from all demodulators in transceivers 254a-254r, perform MIMO detection on the received symbols (if applicable), and provide detected symbols. A receive processor 258 may process (e.g., demodulate, deinterleave, and decode) the detected symbols, provide decoded data for UE 120a to a data sink 260, and provide decoded control information to a controller / processor 280.

[0042] On the uplink, at the UE 120a, a transmit processor 264 may receive and process data from a data source 262 (e.g., for a physical uplink shared channel (PUSCH)) and control information from the controller / processor 280 (e.g., for a physical uplink control channel (PUCCH)). The transmit processor 264 may also generate reference symbols for reference signals (e.g., for a sounding reference signal (SRS)). The symbols from the transmit processor 264 may be precoded by the TX MIMO processor 266 (if applicable), further processed by the demodulators in the transceivers 254a-254r (e.g., for SC-FDM, etc.), and transmitted to the BS 110a. At BS 110a, the uplink signal from UE 120a may be received by antenna 234, processed by the modulators in transceivers 232a-232t, detected by MIMO detector 236 (if applicable), and further processed by receive processor 238 to obtain decoded data and control information sent by UE 120a. Receive processor 238 may provide the decoded data to a data sink 239 and the decoded control information to a controller / processor 240.

[0043] Memories 242 and 282 may store data and program codes for BS 110a and UE 120a, respectively.A scheduler 244 may schedule UEs for data transmission on the downlink and / or uplink.

[0044] NR can utilize orthogonal frequency division multiplexing (OFDM) with a cyclic prefix (CP) on both the uplink and downlink. NR can support half-duplex operation using time division duplexing (TDD). OFDM and single-carrier frequency division multiplexing (SC-FDM) divide the system bandwidth into multiple orthogonal subcarriers, which are also commonly referred to as tones, bins, etc. Each subcarrier can be modulated with data. Modulation symbols can be sent in the frequency domain with OFDM and in the time domain with SC-FDM. The spacing between adjacent subcarriers can be fixed, and the total number of subcarriers can depend on the system bandwidth. The minimum resource allocation, called a resource block (RB), can be 12 consecutive subcarriers. The system bandwidth can also be divided into subbands. For example, a subband can cover multiple RBs. NR can support a basic subcarrier spacing (SCS) of 15 kHz, and other SCSs (e.g., 30 kHz, 60 kHz, 120 kHz, 240 kHz, etc.) can be defined relative to the basic SCS.

[0045] The various techniques and methods described herein may be performed using antennas 252, processors 266, 258, 264, and / or controller / processor 280 of UE 120a and / or antennas 234, processors 220, 230, 238, and / or controller / processor 240 of BS 110a.

[0046] For example, Figure 2 As shown, the controller / processor 240 of the BS 110a has a beam failure manager 112, which is configured to receive a beam failure recovery request (BFRQ) message from a user equipment (UE) in the cell, the BFRQ message including an indication of a candidate recovery beam for a secondary cell (Scell) of the UE. The beam failure manager 112 may also be configured to send a beam failure recovery response (BFRR) message to the UE in response to the BFRQ message, wherein the BFRR message includes one or more of the following types: activation or reconfiguration of a new transmission configuration indicator (TCI) state for the Scell; transmission using a candidate recovery beam for the Scell; or a deactivation command for the Scell.

[0047] UE 120a includes a beam failure manager 122 configured to perform beam failure detection (BFD) of a beam pair link (BPL) associated with a secondary cell (Scell) of a BS (e.g., in carrier aggregation). Beam failure manager 122 may also be configured to send a beam failure recovery request (BFRQ) message in another cell, the BFRQ message including an indication of a candidate recovery beam for the Scell. Beam failure manager 122 may also be configured to start a timer based on sending the BFRQ. Beam failure manager 122 may also be configured to determine whether to resend a beam failure recovery response (BFRR) message in another cell based on whether the BFRQ message is received in the other cell before the timer expires. The beam failure manager 122 may also be configured to resend the BFRQ message in another cell based on the determination, wherein the BFRR message includes one or more of the following types: new transmission configuration indicator (TCI) state activation or reconfiguration for the Scell, transmission using a candidate recovery beam for the Scell, or a deactivation command for the Scell.

[0048] Example beam failure recovery for secondary cell

[0049] In a wireless communication system (e.g., 5G NR), a UE 120a may communicate with a BS 110a via multiple cells (e.g., a primary cell (Pcell) and at least one secondary cell (Scell)) using multiple component carriers (CCs), which may be referred to as carrier aggregation (CA). In some cases, the UE 120a may receive downlink transmissions (e.g., data transmissions) only via the Scell. For example, the UE 120a may receive downlink control signaling (e.g., scheduling resource grants, radio resource control (RRC) signaling, downlink control information (DCI)) from the Pcell on a control resource set (CORESET) of a PDCCH, and receive downlink data transmissions only from the Scell ​​(e.g., communication between the UE 120a and the Scell ​​may be configured without a CORESET for the UE 120a to receive control signaling). The UE 120a may communicate with one or more of the Pcell and the Scell ​​via uplink transmissions.

[0050] In some cases, CA can be used to increase the communication bandwidth between UE 120a and BS 110a. In the case of a beamformed communication system (5G NR), CA can also enable the use of different beams for various traffic flows, such as using a wide beam for broadcast control signaling or a narrow beam for UE-specific data traffic.

[0051] Narrow beam transmission and reception are useful for improving link budget at mmWave frequencies, but can be susceptible to beam failure. Beam failure typically refers to a scenario where the quality of the beam used for the control resource set (CORESET) falls below a threshold, which can lead to radio link failure (RLF). NR supports a low-layer signaling procedure for recovering from beam failure, called the beam failure recovery (BFR) procedure. For example, instead of initiating cell reselection when beam quality becomes too low, intra-cell beam pair reselection can be performed.

[0052] Furthermore, in some cases, the reception of a BFRR message from the BS may be delayed if, for example, the UE is receiving more downlink traffic than uplink traffic, or BS scheduling causes a delay in providing uplink grants to the UE. This delay in receiving the BFRR message may result in additional delays for the BS to generate and communicate instructions regarding the failed Scell, as well as to establish a new link and resume Scell ​​communications. Therefore, described below are methods and techniques for reducing or eliminating communication delays caused by a failed Scell. For example, the UE may communicate candidate beams for Scell ​​recovery in a BFRQ message, and a BFRR transmission in response to the UE may serve not only as an ACK but also as an UL grant for a new transmission from the UE to the Scell, where the BFRR transmission has the same HARQ ID as the BFRQ.

[0053] Figure 3 2 is a call flow illustrating example operations 300 for beam failure detection (BFD) and BFR in accordance with certain aspects of the present disclosure. As shown, a UE 120a is configured to perform BFD for a beam pair link (BPL) associated with a secondary cell (Scell) (e.g., in carrier aggregation) having at least two cells: Scell ​​304 and Pcell 306 (note that in some embodiments, Pcell 306 may alternatively be another Scell).

[0054] Beam failure can be detected by monitoring the BFD Reference Signal (RS) and evaluating whether the beam failure trigger condition has been met. Figure 3 As shown, UE 120a monitors the BFD RS from Scell ​​304 and receives the BFD RS in a first communication 308. In some examples, UE 120a detects a beam failure if an estimated block error rate (BLER) of the RS associated with the configured control resource set (CORESET) is above a threshold (e.g., 10%). In some examples, UE 120a detects a beam failure when UE 120a determines that a reference signal received power (RSRP) of the BPL is below a threshold.

[0055] To recover Scell ​​304, UE 120a may send a beam failure request (BFRQ) message on another cell. The BFRQ may be sent to a Figure 3The Pcell 306 shown, or sent to another Scell ​​(not shown). A two-step BFRQ can be used. For example, after detecting a beam failure, UE 120a can send a first step (or first phase) of a BFRQ in a second communication 310 on Pcell 306. The first step of the BFRQ message can include a scheduling request (SR) on Pcell 306. In some examples, the SR can be sent on a dedicated SR resource. The SR can request scheduling of UE 120a to convey the second step (or second phase) of the BFRQ message.

[0056] like Figure 3 As shown, in a third communication 312, in response to the SR, UE 120a may receive a PDCCH from Pcell 306 for scheduling UE 120a to communicate the second step of the BFRQ message. In some examples, the PDCCH communication may include HARQ information, including one or more of a new data indicator (NDI) and a HARQ process ID for the UE 120a. Figure 3 The second step BFRQ message identifies a specific HARQ process between UE 120a and Pcell 306.

[0057] In response to the PDCCH, the UE 120a may send a second step of the scheduling of the BFRQ message in a fourth communication 314 on the Pcell 306. In some examples, the fourth communication 314 may include a MAC-CE sent on the PUSCH as scheduled by the Pcell 306. The MAC-CE may include an identifier of the failed component carrier (CC) (e.g., a beam or beam pair) (e.g., an index corresponding to the beam or beam pair) and / or an indication of candidate beams for the recovered Scell ​​304. In this way, the UE 120a uses the MAC-CE to report the failed CC index and a new candidate beam to replace the failed beam.

[0058] To find candidate new beams, UE 120a can monitor the beam identification RS. For example, upon detecting a beam failure by UE 120a, UE 120a can identify new candidate beams by monitoring the beam identification RS and selecting a beam with good reception quality based on the measured reception quality. The RS used for new beam identification can include a channel state information-reference signal (CSI-RS) and / or a synchronization signal (SS) block. For example, UE 120a can monitor the candidate new beams transmitted by Scell ​​304 before, during, or after BFD.

[0059] In certain aspects, UE 120a may start a timer when sending a BFRQ or when determining to send a BFRQ. For example, UE 120a may start a timer when sending the first or second step of the BFRQ. In some examples, UE 120a may determine whether to resend the first or second step of the BFRQ message to Pcell 306 based on whether a BFRR message is received from another cell before the timer expires. For example, if the timer duration expires and UE 120a does not receive a BFRR, UE 120a may resend the first or second step of the BFRQ message. In some examples, if UE 120a has retransmitted the first or second step of the BFRQ message a threshold number of retransmissions, UE 120a may refrain from resending the BFRQ message to Pcell 306. Conversely, if UE 120a fails to detect any response after the threshold number of retransmissions, UE 120a may notify higher layers (e.g., the core network), potentially causing RLF and cell reselection.

[0060] The BFRR message can be sent to UE 120a in one of two ways. In a fifth communication 316, Pcell 306 responds to the second step of the BFRQ by sending a Beam Failure Recovery Response (BFRR) message to UE 120a. The BFRR message can acknowledge the MAC-CE and include an uplink grant (e.g., a downlink control information (DCI) message) that schedules a new uplink transmission by UE 120a. In some examples, the uplink grant can schedule the new uplink transmission using the same HARQ process ID used in the PUSCH that carried the MAC-CE in the second step of the BFRQ and identified by Pcell 306 in the third communication 312. In some examples, the BFRR is sent via the CORESET (e.g., referred to as CORESET-BFR), and UE 120a monitors for a response from Pcell 306. As an alternative to fifth communication 316, a sixth communication 318 can be sent from Scell ​​304. The sixth communication 318 may be transmission of a beam recovery using the Scell ​​candidate identified by the MAC-CE.

[0061] In certain aspects, the BFRR message includes one or more of: (i) a new transmission configuration indicator (TCI) state activation or reconfiguration for the Scell ​​304 provided to the UE 120a by the Pcell 306 or another cell, (ii) a transmission from the Scell ​​304 to the UE 120a using a candidate recovery beam for the Scell ​​304, or (iii) a deactivation command for the Scell ​​304 provided to the UE 120a by the Pcell 306 or another cell.

[0062] The new TCI may include, among other things, information about reference signals (RSs) (e.g., CSI-RSs and / or SS blocks). Here, by providing the new TCI state to UE 120a, Pcell 306 associates the new TCI state with the RSs transmitted by Scell ​​304 (e.g., the RSs used by UE 120a for BFD in first communication 308). Thus, the Pcell informs UE 120a that it can assume that the RSs transmitted by Scell ​​304 use the same spatial filter associated with the TCI. In some examples, the BFRR message may include the new TCI state as part of a scheduling assignment that indicates to UE 120a the quasi-coordinated (QCL) relationship to use (e.g., which receive beams UE 120a may use) to receive the RSs transmitted by Scell ​​304. Consequently, UE 120a can use the new TCI state to reset its TCI state with Scell ​​304 and resume communication with Scell ​​304. Therefore, because the BFRR message includes the new TCI state, UE 120a can directly communicate with Scell ​​304 using the new TCI, thereby saving latency and overhead. Without the new TCI state in the BFRR message, UE 120a would need to wait for additional signaling from Pcell 306 to reset the TCI of Scell ​​304 and then communicate this data to UE 120a.

[0063] As discussed, in the fourth communication 314, Scell ​​304 may send a BFRR message to UE 120a using the candidate recovery beam indicated by UE 120a. That is, Scell ​​304 may send a BFRR message to UE 120a using the candidate beam of Scell ​​304 identified by UE 120a in the MAC-CE. In some examples, the BFRR message is a PDCCH sent on predefined resources using the candidate recovery beam. In this example, after sending the MAC-CE of the fourth communication 314, UE 120a monitors the predefined resources and the candidate recovery beam for a duration after sending the MAC-CE (e.g., a predetermined duration of a timer). If UE 120a does not receive the BFRR message within the duration of the timer, UE 120a may retransmit the first step (or first stage) of the BFRQ of the second communication 310. After receiving the BFRR within the duration of the timer, the UE may stop the timer and refrain from retransmitting the BFRQ of the second communication 310.

[0064] In some examples, predefined PDCCH resources may be defined in a wireless communication standard (e.g., 3GPP) that directs communications among UE 120a, Scell ​​304, and Pcell 306. In some examples, the predefined PDCCH resources may be defined by signaling prior to BFR. For example, certain tones in certain symbols may be candidates for a PDCCH search space, where those tones and symbols are defined in the wireless communication standard. In this example, UE 120a may use blind decoding of potential PDCCHs in those candidate search spaces. Note that in the search space, there may be multiple candidate locations where a PDCCH will be transmitted: therefore, UE 120a may blind decode all candidate locations. If UE 120a determines that the scrambling sequence of the CRC at the decoded location matches the UE's own sequence, then UE 120a detects the PDCCH.

[0065] UE 120a may use the TCI status of the candidate beam to reset its TCI status with Scell ​​304 and resume communication with Scell ​​304. Alternatively, if UE 120a does not receive a new TCI status or a BFRR message, UE 120a may assume that the candidate beam indicated in the MAC-CE is a new TCI status of a receive beam that UE 120a may use to receive signaling from Scell ​​304. Therefore, UE 120a may use the TCI status of the candidate beam to reset its TCI status with respect to Scell ​​304 to resume communication with Scell ​​304.

[0066] In some examples, the BFRR message may include a deactivation command for Scell ​​304. In CA, activation and deactivation of a CC (e.g., the CC of Scell ​​304) may be accomplished through MAC-CE signaling. For example, the MAC-CE signaling may include a bitmap where each bit indicates whether Scell ​​304 should be activated or deactivated. The deactivation command may be sent by Pcell 306 to UE 120a on the PDSCH. Here, UE 120a may assume that all communications between UE 120a and Scell ​​304 will cease until UE 120a is explicitly notified of the reactivation of Scell ​​304. In some examples, base station 110 may perform the deactivation of Scell ​​304.

[0067] Figure 4 4 is a flow diagram illustrating example operations 400 for wireless communication according to certain aspects of the present disclosure. Operations 400 may be performed, for example, by a UE (e.g., UE 120a in wireless communication network 100). Operations 400 may be implemented as a process on one or more processors (e.g., Figure 2In addition, the system can be connected to the network via one or more antennas (e.g., Figure 2 The antenna 252 of the UE may be used to implement the transmission and reception of signals by the UE in operation 400. In some aspects, the transmission and / or reception of signals by the UE may be implemented via a bus interface of one or more processors (e.g., controller / processor 280) that obtain and / or output signals.

[0068] Operations 400 begin at block 402 by performing beam failure detection (BFD) of a beam pair link (BPL) associated with a secondary cell (Scell) of a base station (BS) (eg, in carrier aggregation (CA)).

[0069] Operation 400 proceeds to block 404 by sending a beam failure recovery request (BFRQ) message in another cell of the BS, the BFRQ message including an indication of a candidate recovery beam for the Scell.

[0070] Operation 400 proceeds to block 406 where a timer is started based on sending the BFRQ.

[0071] Operation 400 proceeds to block 408, determining whether to resend a beam failure recovery response (BFRR) message in another cell based on whether a BFRQ message is received in another cell before the timer expires, and

[0072] Operation 400 proceeds to block 410 where, based on the determination, a BFRQ message is retransmitted (or retransmission of the BFRQ message is avoided) in another cell, wherein the BFRR message includes one or more of the following types: (i) a new transmission configuration indicator (TCI) state activation or reconfiguration for the Scell, (ii) a transmission using a candidate recovery beam for the Scell, or (iii) a deactivation command for the Scell.

[0073] In certain aspects, the BFRR message also includes an uplink grant for a new transmission with the same hybrid automatic repeat request (HARQ) process as the uplink channel carrying the BFRR message.

[0074] In certain aspects, the another cell is a primary cell.

[0075] In certain aspects, a new TCI state activation or reconfiguration for a Scell ​​is received in a medium access control (MAC) control element (CE) on a physical downlink shared channel (PDSCH) in another cell.

[0076] In certain aspects, a new TCI state activation or reconfiguration for the Scell ​​is received in another cell. For example, the new TCI state activation or reconfiguration for the Scell ​​may be received in a media access control (MAC) control element (CE) on a physical downlink shared channel (PDSCH) in the other cell.

[0077] In certain aspects, the transmission using the candidate recovery beam for the Scell ​​is a physical downlink control channel (PDCCH).

[0078] In certain aspects, a transmission using a candidate recovery beam for a Scell ​​is sent in predefined resources.

[0079] In certain aspects, the predefined resources include one or more frequency and time resources.

[0080] In certain aspects, the transmission using the candidate recovery beam for the Scell ​​is sent in the resources indicated to the UE.

[0081] In certain aspects, radio resource control (RRC) signaling is used to indicate resources to the UE.

[0082] In certain aspects, the operations 400 include monitoring resources for transmission using a candidate recovery beam for the Scell ​​within a time period after sending the BFRQ message.

[0083] In certain aspects, the time period is indicated to the UE.

[0084] In certain aspects, the time period is indicated to the UE using radio resource control (RRC) signaling.

[0085] In certain aspects, monitoring includes setting a receive beam of the UE to receive a candidate recovery beam for the Scell.

[0086] In certain aspects, the time period is based on the UE capabilities of the UE.

[0087] In certain aspects, the deactivation command is received in a medium access control (MAC) control element (CE) on a physical downlink shared channel (PDSCH) in another cell.

[0088] In certain aspects, the deactivation command is received in the other cell.For example, the deactivation command may be received in the other cell in a medium access control (MAC) control element (CE) on a physical downlink shared channel (PDSCH).

[0089] In certain aspects, operations 400 include receiving an indication of which one or more types of BFRR messages to monitor.

[0090] In certain aspects, operations 400 include monitoring for the indicated one or more types of BFRR messages.

[0091] In certain aspects, operation 400 includes determining one or more receive beams for monitoring based on the indicated one or more types.

[0092] In certain aspects, operations 400 include receiving a BFRR message, wherein the BFRR message includes a deactivation command for the Scell, and deactivating the Scell ​​based on receiving the BFRR message.

[0093] In certain aspects, the operations 400 include receiving a BFRR message, wherein the BFRR message includes a new TCI state activation or reconfiguration for the Scell, and resetting the TCI state of the Scell ​​to the new TCI state based on receiving the BFRR message.

[0094] In certain aspects, operations 400 include receiving a BFRR message, wherein the BFRR message includes an uplink grant; and resetting a TCI state of the Scell ​​to a candidate recovery beam based on receiving the BFRR message.

[0095] In certain aspects, a new TCI state activation or reconfiguration for the Scell ​​is a candidate recovery beam for the Scell.

[0096] Figure 5 5 is a flow diagram illustrating example operations 500 for wireless communication according to certain aspects of the present disclosure. Operations 500 may be performed, for example, by a base station (e.g., BS 110a in wireless communication network 100). Operations 500 may be complementary to operations 400 performed by a UE. Operations 500 may be implemented as a process on one or more processors (e.g., Figure 2 In addition, the system can be connected to the network through one or more antennas (e.g., Figure 2 The transmission and reception of signals by the BS in operation 500 may be implemented using antenna 234. In some aspects, the transmission and / or reception of signals by the BS may be implemented via a bus interface of one or more processors (e.g., controller / processor 240) that obtain and / or output signals.

[0097] Operations 500 begin at block 502 by receiving a beam failure recovery request (BFRQ) message from a user equipment (UE) in a cell, the BFRQ message including an indication of candidate recovery beams for a secondary cell (Scell) of the UE.

[0098] Operation proceeds to block 504 where, in response to the BFRQ message, a beam failure recovery response (BFRR) message is sent to the UE, wherein the BFRR message includes one or more of the following types: (i) new transmission configuration indicator (TCI) state activation or reconfiguration for the Scell, (ii) transmission using a candidate recovery beam for the Scell, or (iii) a deactivation command for the Scell.

[0099] In certain aspects, the BFRR message also includes an uplink grant for a new transmission with the same hybrid automatic repeat request (HARQ) process as the uplink channel carrying the BFRR message.

[0100] In certain aspects, the cell is a primary cell.

[0101] In certain aspects, a new TCI state activation or reconfiguration for a Scell ​​is sent in a Medium Access Control (MAC) Control Element (CE) on a Physical Downlink Shared Channel (PDSCH) in the cell.

[0102] In certain aspects, a new TCI state activation or reconfiguration for the Scell ​​is sent in the cell. For example, the new TCI state activation or reconfiguration for the Scell ​​may be sent in a medium access control (MAC) control element (CE) on a physical downlink shared channel (PDSCH) in the cell.

[0103] In certain aspects, the transmission using the candidate recovery beam for the Scell ​​is a physical downlink control channel (PDCCH).

[0104] In certain aspects, a transmission using a candidate recovery beam for a Scell ​​is sent in predefined resources.

[0105] In certain aspects, the predefined resources include one or more frequency and time resources.

[0106] In certain aspects, the transmission using the candidate recovery beam for the Scell ​​is sent in the resources indicated to the UE.

[0107] In certain aspects, the resources are indicated to the UE using radio resource control (RRC) signaling.

[0108] In certain aspects, the deactivation command is sent in a Medium Access Control (MAC) Control Element (CE) on a Physical Downlink Shared Channel (PDSCH) in a cell.

[0109] In certain aspects, the deactivation command is sent in a cell.

[0110] In certain aspects, operations 500 include sending an indication to the UE as to which type or types of BFRR messages to monitor.

[0111] In certain aspects, a new TCI state activation or reconfiguration for the Scell ​​is a candidate recovery beam for the Scell.

[0112] Figure 6 Illustrated is a communication device 600 (eg, UE 120a) that may include various components (eg, corresponding to means plus function components) configured to perform operations of the techniques disclosed herein, such as Figure 4 The communication device 600 includes a processing system 602 coupled to a transceiver 608 (e.g., a transmitter and / or a receiver). The transceiver 608 is configured to transmit and receive signals for the communication device 600, such as the various signals described herein, via an antenna 610. The processing system 602 can be configured to perform processing functions for the communication device 600, including processing signals received and / or transmitted by the communication device 600.

[0113] The processing system 602 includes a processor 604 coupled to a computer-readable medium / memory 612 via a bus 606. In some aspects, the computer-readable medium / memory 612 is configured to store instructions (e.g., computer-executable code) that, when executed by the processor 604, cause the processor 604 to perform Figure 4 The operations shown, or other operations for performing various techniques for beam failure recovery discussed herein. In certain aspects, the computer-readable medium / memory 612 stores code 630 for performing BFD for a BPL associated with a Scell ​​of the BS in CA; code 632 for sending a BFRQ message in another cell of the BS, the BFRQ message including an indication of a candidate recovery beam for the Scell; code 634 for starting a timer based on sending the BFRQ; code 636 for determining whether to resend the BFRQ message in the other cell based on whether a BFRR message is received in the other cell before expiration of the timer; and / or code 638 for resending the BFRQ message in the other cell (or refraining from resending the BFRQ message) based on the determination, wherein the BFRR message includes one or more of the following types: a new transmission configuration indicator (TCI) state activation or reconfiguration for the Scell, a transmission using the candidate recovery beam for the Scell, or a deactivation command for the Scell.

[0114] In certain aspects, the processor 604 includes circuitry configured to implement code stored in the computer-readable medium / memory 612. The processor 604 includes circuitry 620 for performing BFD for a BPL associated with a Scell ​​of the BS in CA; circuitry 622 for sending a BFRQ message in another cell of the BS, the BFRQ message including an indication of a candidate recovery beam for the Scell; circuitry 624 for starting a timer based on sending the BFRQ; circuitry 626 for determining whether to resend the BFRQ message in the other cell based on whether a beam failure recovery response (BFRR) message is received in the other cell before expiration of the timer; and / or circuitry 628 for resending the BFRQ message in the other cell (or refraining from resending the BFRQ message) based on the determination, wherein the BFRR message includes one or more of the following types: a new transmission configuration indicator (TCI) state activation or reconfiguration for the Scell, a transmission using the candidate recovery beam for the Scell, or a deactivation command for the Scell.

[0115] Figure 7 Illustrated is a communication device 700 (eg, BS 110a) that may include various components (eg, corresponding to means plus function components) configured to perform operations of the techniques disclosed herein, such as Figure 5 The communication device 700 includes a processing system 702 coupled to a transceiver 708 (e.g., a transmitter and / or a receiver). The transceiver 708 is configured to transmit and receive signals for the communication device 700, such as the various signals described herein, via an antenna 710. The processing system 702 can be configured to perform processing functions for the communication device 700, including processing signals received and / or transmitted by the communication device 700.

[0116] The processing system 702 includes a processor 704 coupled to a computer-readable medium / memory 712 via a bus 706. In some aspects, the computer-readable medium / memory 712 is configured to store instructions (e.g., computer-executable code) that, when executed by the processor 704, cause the processor 704 to perform Figure 5The operations shown, or other operations for performing the various techniques for beam failure recovery discussed herein. In certain aspects, the computer-readable medium / memory 712 stores code 714 for receiving a BFRQ message from a UE in a cell, the BFRQ message including an indication of a candidate recovery beam for a Scell ​​of the UE; and code 716 for sending a beam failure recovery response (BFRR) message to the UE in response to the BFRQ message, wherein the BFRR message includes one or more of the following types: a new transmission configuration indicator (TCI) state activation or reconfiguration for the Scell, a transmission using the candidate recovery beam for the Scell, or a deactivation command for the Scell.

[0117] In certain aspects, the processor 704 includes circuitry configured to implement code stored in the computer-readable medium / memory 712. The processor 704 includes circuitry 720 for receiving a BFRQ message from a UE in a cell, the BFRQ message including an indication of a candidate recovery beam for a Scell ​​of the UE; and circuitry 722 for sending a BFRR message to the UE in response to the BFRQ message, wherein the BFRR message includes one or more of the following types: a new TCI state activation or reconfiguration for the Scell, a transmission using the candidate recovery beam for the Scell, or a deactivation command for the Scell.

[0118] Exemplary embodiments

[0119] Embodiment 1: A method for wireless communication by a user equipment (UE), comprising: performing beam failure detection (BFD) of a beam pair link (BPL) associated with a secondary cell (Scell) of a base station (BS); sending a beam failure recovery request (BFRQ) message in another cell of the BS, the BFRQ message including an indication of a candidate recovery beam for the Scell; starting a timer based on sending the BFRQ; determining whether to resend the BFRQ message in another cell based on whether a beam failure recovery response (BFRR) message is received before expiration of the timer; and resending the BFRQ message in another cell based on the determination, wherein the BFRR message includes one or more of the following types: activation or reconfiguration of a new transmission configuration indicator (TCI) state for the Scell, transmission using the candidate recovery beam for the Scell, or a deactivation command for the Scell.

[0120] Embodiment 2: The method of embodiment 1, wherein the BFRR message further includes an uplink grant for a new transmission having the same hybrid automatic repeat request (HARQ) process as the uplink channel carrying the BFRR message.

[0121] Embodiment 3: The method according to any one of embodiments 1 or 2, wherein the other cell is a primary cell.

[0122] Embodiment 4: The method according to any one of embodiments 1-3, wherein the new TCI state activation or reconfiguration for the Scell ​​is received in a medium access control (MAC) control element (CE) on a physical downlink shared channel (PDSCH) in another cell.

[0123] Embodiment 5: The method according to any one of embodiments 1-4, wherein a new TCI state activation or reconfiguration for the Scell ​​is received in the other cell.

[0124] Embodiment 6: The method according to any one of embodiments 1-5, wherein the transmission using the candidate recovery beam for the Scell ​​is a physical downlink control channel (PDCCH).

[0125] Embodiment 7: The method according to any one of embodiments 1-6, wherein the transmission using the candidate recovery beam for the Scell ​​is sent in predetermined resources.

[0126] Embodiment 8: The method according to any one of embodiments 1-7, wherein the predefined resources include one or more frequency and time resources.

[0127] Embodiment 9: The method according to any one of embodiments 1-8, wherein the transmission using the candidate recovery beam for the Scell ​​is sent in the resources indicated to the UE.

[0128] Embodiment 10: The method according to any one of embodiments 1-9, wherein the resources are indicated to the UE using radio resource control (RRC) signaling.

[0129] Embodiment 11: The method according to any one of embodiments 1-10 further comprises monitoring resources used for transmission using the candidate recovery beam for the Scell ​​within a period of time after sending the BFRQ message.

[0130] Embodiment 12: The method according to any one of embodiments 1-11, wherein the time period is indicated to the UE.

[0131] Embodiment 13: The method according to any one of embodiments 1-12, wherein the time period is indicated to the UE using radio resource control (RRC) signaling.

[0132] Embodiment 14: The method according to any one of embodiments 1-13, wherein the time period is based on the UE capability of the UE.

[0133] Embodiment 15: The method according to any one of embodiments 1-14, wherein the monitoring includes setting a receive beam of the UE to receive a candidate recovery beam for the Scell.

[0134] Embodiment 16: The method of any one of embodiments 1-15, wherein the deactivation command is received in a medium access control (MAC) control element (CE) on a physical downlink shared channel (PDSCH) in another cell.

[0135] Embodiment 17: The method according to any one of embodiments 1-16, wherein a deactivation command is received in the other cell.

[0136] Embodiment 18: The method according to any one of embodiments 1-17 further includes receiving an indication of which one or more types of BFRR messages to monitor.

[0137] Embodiment 19: The method according to any one of embodiments 1-18 further includes monitoring the indicated one or more types of BFRR messages.

[0138] Embodiment 20: The method according to any one of embodiments 1-19, further comprising determining one or more receive beams to be used for monitoring based on the indicated one or more types.

[0139] Embodiment 21: The method according to any one of embodiments 1-20 further includes receiving a BFRR message, wherein the BFRR message includes a deactivation command for the Scell; and deactivating the Scell ​​based on receiving the BFRR message.

[0140] Embodiment 22: The method according to any one of embodiments 1-21 further includes: receiving a BFRR message, the BFRR message including activation or reconfiguration of a new TCI state for the Scell; and resetting the TCI state of the Scell ​​to the new TCI state based on receiving the BFRR message.

[0141] Embodiment 23: The method according to any one of embodiments 1-22 further includes: receiving a BFRR message, the BFRR message including an uplink grant; and resetting the TCI state of the Scell ​​to a candidate recovery beam based on receiving the BFRR message.

[0142] Embodiment 24: The method according to any one of embodiments 1-23, wherein the new TCI state activation or reconfiguration for the Scell ​​is a candidate recovery beam for the Scell.

[0143] Embodiment 25: A method for wireless communication by a base station (BS), comprising: receiving a beam failure recovery request (BFRQ) message from a user equipment (UE) in a cell, the BFRQ message including an indication of a candidate recovery beam for a secondary cell (Scell) of the UE; and sending a beam failure recovery response (BFRR) message to the UE in response to the BFRQ message, the BFRR message including one or more of the following types: activation or reconfiguration of a new transmission configuration indicator (TCI) state for the Scell; transmission using the candidate recovery beam for the Scell; or a deactivation command for the Scell.

[0144] Embodiment 26: The method of embodiment 25, wherein the BFRR message further includes an uplink grant for a new transmission having the same hybrid automatic repeat request (HARQ) process as the uplink channel carrying the BFRR message.

[0145] Embodiment 27: The method according to any one of embodiments 25 or 26, wherein the cell is a primary cell.

[0146] Embodiment 28: The method according to any one of embodiments 25-27, wherein the new TCI state activation or reconfiguration for the Scell ​​is sent in a medium access control (MAC) control element (CE) on a physical downlink shared channel (PDSCH) in the cell.

[0147] Embodiment 29: The method according to any one of embodiments 25-28, wherein a new TCI state activation or reconfiguration for the Scell ​​is sent in the cell.

[0148] Embodiment 30: The method according to any one of embodiments 25-29, wherein the transmission using the candidate recovery beam for the Scell ​​is a physical downlink control channel (PDCCH).

[0149] Embodiment 31: The method of any one of embodiments 25-30, wherein the transmission using the candidate recovery beam for the Scell ​​is sent in predetermined resources.

[0150] Embodiment 32: The method according to any one of embodiments 25-31, wherein the predefined resources include one or more frequency and time resources.

[0151] Embodiment 33: The method according to any one of embodiments 25-32, wherein the transmission using the candidate recovery beam for the Scell ​​is sent in the resources indicated to the UE.

[0152] Embodiment 34: The method of any one of embodiments 25-33, wherein the resources are indicated to the UE using radio resource control (RRC) signaling.

[0153] Embodiment 35: The method according to any one of embodiments 25-34, wherein the deactivation command is sent in a medium access control (MAC) control element (CE) on a physical downlink shared channel (PDSCH) in the cell.

[0154] Embodiment 36: A method according to any one of embodiments 25-35, wherein a deactivation command is sent in the cell.

[0155] Embodiment 37: The method according to any one of embodiments 25-36 further comprises sending an indication to the UE of which one or more types of BFRR messages to monitor.

[0156] Embodiment 38: The method according to any one of embodiments 25-37, wherein the new TCI state activation or reconfiguration for the Scell ​​is a candidate recovery beam for the Scell.

[0157] Embodiment 39: A user equipment (UE), comprising: a memory; and a processor, communicatively coupled to the memory, the processor configured to: perform beam failure detection (BFD) of a beam pair link (BPL) associated with a secondary cell (Scell) of a base station (BS); send a beam failure recovery request (BFRQ) message in another cell of the BS, the BFRQ message including an indication of a candidate recovery beam for the Scell; start a timer based on sending the BFRQ; determine whether to resend the BFRQ message in the other cell based on whether a beam failure recovery response (BFRR) message is received before the timer expires; and resend the BFRQ message in the other cell (or avoid resending the BFRQ message) based on the determination, wherein the BFRR message includes one or more of the following types: activation or reconfiguration of a new transmission configuration indicator (TCI) state for the Scell; transmission using the candidate recovery beam for the Scell; or a deactivation command for the Scell.

[0158] Embodiment 40: The UE of embodiment 39, wherein the BFRR message further includes an uplink grant for a new transmission having the same hybrid automatic repeat request (HARQ) process as the uplink channel carrying the BFRR message.

[0159] Embodiment 41: The UE according to any one of embodiments 39 and 40, wherein the new TCI state activation or reconfiguration for the Scell ​​is received in a medium access control (MAC) control element (CE) on a physical downlink shared channel (PDSCH) in another cell.

[0160] Embodiment 42: The UE according to any one of embodiments 39-41, wherein a new TCI state activation or reconfiguration for the Scell ​​is received in the other cell.

[0161] Embodiment 43: The UE according to any one of embodiments 39-42, wherein the transmission using the candidate recovery beam for the Scell ​​is a physical downlink control channel (PDCCH).

[0162] Embodiment 44: The UE according to any one of embodiments 39-43, wherein the transmission using the candidate recovery beam for the Scell ​​is sent in predetermined resources.

[0163] Embodiment 45: A base station (BS), comprising: a memory; and a processor, communicatively coupled to the memory, the processor being configured to: receive a beam failure recovery request (BFRQ) message from a user equipment (UE) in a cell, the BFRQ message including an indication of a candidate recovery beam for a secondary cell (Scell) of the UE; and send a beam failure recovery response (BFRR) message to the UE in response to the BFRQ message, wherein the BFRR message includes one or more of the following types: activation or reconfiguration of a new transmission configuration indicator (TCI) state for the Scell; transmission using the candidate recovery beam for the Scell; or a deactivation command for the Scell.

[0164] Additional considerations

[0165] The techniques described herein can be used for various wireless communication technologies such as NR (e.g., 5G NR), 3GPP Long Term Evolution (LTE), LTE Advanced (LTE-A), Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), Single Carrier Frequency Division Multiple Access (SC-FDMA), Time Division Synchronous Code Division Multiple Access (TD-SCDMA), 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), CDMA2000, and the like. UTRA includes Wideband CDMA (WCDMA) and other variants of CDMA. CDMA2000 covers IS-2000, IS-95, and IS-856 standards. A TDMA system can implement a radio technology such as Global System for Mobile Communications (GSM). OFDMA networks 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), IEEE 802.20, Flash-OFDMA, and the like. UTRA and E-UTRA are part of the Universal Mobile Telecommunications System (UMTS). LTE and LTE-A are versions of UMTS that use E-UTRA. UTRA, E-UTRA, UMTS, LTE-a, and GSM are described in documents from an organization named "3rd Generation Partnership Project" (3GPP). CdMA2000 and UMB are described in documents from an organization named "3rd Generation Partnership Project 2" (3GPP2). NR is an emerging wireless communication technology under development.

[0166] The techniques described herein can be used for the wireless networks and radio technologies described above as well as other wireless networks and radio technologies. For clarity, although terms commonly associated with 3G, 4G, and / or 5G wireless technologies may be used herein to describe various aspects, various aspects of the present disclosure may be applied to other generation-based communication systems.

[0167] In 3GPP, the term "cell" can refer to the coverage area of ​​a Node B (NB) and / or the NB subsystem serving that coverage area, depending on the context in which the term is used. In NR systems, the terms "cell" and "base station," next-generation Node B (gNB or gNodeB), access point (AP), distributed unit (DU), carrier, or transmit / receive point (TRP) are used interchangeably. A base station (BS) can provide communication coverage for macrocells, picocells, femtocells, and / or other types of cells. A macrocell can cover a relatively large geographic area (e.g., several kilometers in radius) and can allow unrestricted access to UEs with service subscriptions. A picocell can cover a relatively small geographic area and can allow unrestricted access to UEs with service subscriptions. A femtocell can cover a relatively small geographic area (e.g., a home) and can allow restricted access to UEs associated with the femtocell (e.g., UEs in a closed subscriber group (CSG), UEs of users in a home, etc.). A base station for a macrocell can be referred to as a macro BS. A base station for a picocell can be referred to as a pico BS. A base station for a femtocell can be referred to as a femto BS or a home BS.

[0168] A 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 smartphone, 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, an appliance, a medical device or medical equipment, a biometric sensor / device, a wearable device such as a smart watch, smart clothing, smart glasses, a smart wristband, smart jewelry (e.g., a smart ring, a smart wristband, etc.), an entertainment device (e.g., a music device, a video device, a satellite radio, etc.), a vehicle component or sensor, a smart meter / sensor, an industrial manufacturing device, a global positioning system device, or any other suitable device configured to communicate via a wireless or wired medium. Some UEs may be considered machine type communication (MTC) devices or evolved MTC (eMTC) devices. 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 or to a network (e.g., a wide area network such as the Internet or a cellular network) via, for example, a wired or wireless communication link. Some UEs can be considered Internet of Things (IoT) devices, which can be narrowband IoT (NB-IoT) devices.

[0169] 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, bins, etc. Each subcarrier can be modulated with data. In general, modulation symbols are sent in the frequency domain with OFDM and in the time domain with 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 subcarrier spacing can be 15 kHz, and the minimum resource allocation (called a "resource block") can be 12 subcarriers (or 180 kHz). 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 can also be divided into subbands. For example, a subband may cover 1.8 MHz (e.g., 6 RBs), 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.In LTE, the basic transmission time interval (TTI) or packet duration is a 1 ms subframe.

[0170] NR can utilize OFDM with CP on both the uplink and downlink and includes support for half-duplex operation using TDD. In NR, the subframe is still 1ms, but the basic TTI is called a slot. A subframe contains a variable number of slots (e.g., 1, 2, 4, 8, 16, ... slots) depending on the subcarrier spacing. An NR RB is 12 consecutive frequency subcarriers. NR can support a basic subcarrier spacing of 15 kHz, and other subcarrier spacings can be defined relative to the basic subcarrier spacing, such as 30 kHz, 60 kHz, 120 kHz, 240 kHz, etc. Symbol and slot lengths are proportional to the subcarrier spacing. The CP length also depends on the subcarrier spacing. Beamforming can be supported and the beam direction can be dynamically configured. MIMO transmission with precoding can also be supported. In some examples, MIMO configurations in the DL can support up to 8 transmit antennas, with multi-layer DL transmission of up to 8 streams and up to 2 streams per UE. In some examples, multi-layer transmission with up to 2 streams per UE can be supported. Up to 8 serving cells can be used to support aggregation of multiple cells.

[0171] In some examples, access to the air interface can be scheduled. A scheduling entity (e.g., a BS) allocates resources for communications between some or all devices and equipment within its service area or cell. A scheduling entity can be responsible for scheduling, allocating, reconfiguring, and releasing resources for one or more subordinate entities. That is, for scheduled communications, a subordinate entity utilizes resources allocated by the scheduled entity. The base station is not the only entity that can be used as a scheduling entity. In some examples, a UE can be used 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 utilize the resources scheduled by the UE for wireless communications. 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.

[0172] In some examples, two or more slave entities (e.g., UEs) can communicate with each other using sidelink signals. Real-world applications of such sidelink communications may include public safety, proximity services, UE-to-network relay, vehicle-to-vehicle (V2V) communications, Internet of Everything (IoE) communications, IoT communications, mission-critical grids, and / or various other suitable applications. Generally speaking, a sidelink signal can refer to a signal communicated from one slave entity (e.g., UE1) to another slave entity (e.g., UE2) without relaying the communication through a scheduling entity (e.g., UE or BS), even though the scheduling entity can be used for scheduling and / or control purposes. In some examples, the sidelink signal can be sent using licensed spectrum (unlike wireless local area networks that typically use unlicensed spectrum).

[0173] The method disclosed herein includes one or more steps or actions for implementing the method. Method steps and / or actions may be interchangeable with each other without departing from the scope of the claims. In other words, unless a specific order of steps or actions is specified, the order and / or use of specific steps and / or actions may be modified without departing from the scope of the claims.

[0174] As used herein, a phrase reciting "at least one of" a list of items refers to any combination of those items, including single members. As an example, "at least one of a, b, or c" is intended to encompass: a, b, c, ab, ac, bc, and abc, as well as any combination with multiples of the same element (e.g., aa, aaa, aab, aac, abb, acc, bb, bbb, bbc, cc, and ccc, or any other ordering of a, b, and c).

[0175] As used herein, the term "determine" includes a variety of actions. For example, "determine" may include calculating, computing, processing, deriving, investigating, searching (e.g., searching in a table, database, or another data structure), ascertaining, etc. Furthermore, "determine" may include receiving (e.g., receiving information), accessing (e.g., accessing data in a memory), etc. Furthermore, "determine" may include resolving, selecting, choosing, establishing, etc.

[0176] The previous description is provided to enable those skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects. Therefore, the present claims are not intended to be limited to the aspects shown herein, but rather to the full scope consistent with the language claims, wherein, unless otherwise specified, reference to an element in the singular is not intended to mean "one and only one," but rather "one or more." Unless otherwise specifically stated, the term "some" refers to one or more. All structural and functional equivalents of the elements throughout the various aspects described in this disclosure that are known or will later be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be covered by the claims. In addition, nothing disclosed herein is intended to be contributed to the public, regardless of whether such disclosure is explicitly stated in the claims. An element of a claim should not be interpreted as being pursuant to 35 U.S.C. § 112(f) unless the element is explicitly stated using the phrase "for ... means," or in the case of a method claim, the element is stated using the phrase "for ... step."

[0177] The various operations of the above method can be performed by any suitable component capable of performing the corresponding function. The component 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 there are operations shown in the figures, those operations may have corresponding component-plus-function components with similar numbers.

[0178] The various illustrative logical blocks, modules, and circuits described in connection with the present disclosure may be implemented or performed with a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device (PLD), discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, 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 (e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration).

[0179] If 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. The bus may include any number of interconnecting buses and bridges, depending on the specific application and overall design constraints of the processing system. The bus may connect various circuits including a processor, a machine-readable medium, and a bus interface. The bus interface may be used to connect a network adapter to the processing system via the bus. The network adapter may be used to implement signal processing functions at the physical (PHY) layer. In the user equipment 120 (see Figure 1 ), a user interface (e.g., a keypad, display, mouse, joystick, etc.) may also be connected to the bus. The bus may also link various other circuits, such as timing sources, peripherals, voltage regulators, power management circuits, etc., which are well known in the art and will not be described further. The processor may be implemented using one or more general and / or special purpose processors. Examples include microprocessors, microcontrollers, DSP processors, and other circuits capable of executing software. Those skilled in the art will recognize how best to implement the described functions of the processing system, which depends on the specific application and the overall design constraints imposed on the entire system.

[0180] If implemented in software, the functions may be stored on or transmitted through a computer-readable medium as one or more instructions or codes. Software should be broadly interpreted to mean instructions, data, or any combination thereof, whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise. Computer-readable media include both computer storage media and communication media, including any medium that facilitates the transmission of computer programs from one place to another. The processor may be responsible for managing the bus and general processing, including the execution of software modules stored on the machine-readable storage medium. The computer-readable storage medium may be coupled to the processor so that the processor can read information from and write information to the storage medium. In an alternative embodiment, the storage medium may be integrated into the processor. For example, the machine-readable medium may include a transmission line, a carrier modulated by data, and / or a computer-readable storage medium having instructions stored thereon that is separate from the wireless node, all of which can be accessed by the processor via a bus interface. Alternatively or in addition, the machine-readable medium or any portion thereof may be integrated into the processor, such as with 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 drives, or any other suitable storage media, or any combination thereof. Machine-readable media may be included in a computer program product.

[0181] A software module may include a single instruction or many instructions and may be distributed across several different code segments, in different programs, and across multiple storage media. A computer-readable medium may include multiple software modules. A software module includes 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 sending module and a receiving module. Each software module may reside in a single storage device or be distributed across multiple storage devices. For example, when a triggering event occurs, a software module may be loaded from a hard drive into RAM. During execution of a software module, the processor may load some instructions into a cache to increase access speed. One or more cache lines may then be loaded into a general register file for execution by the processor. When referring to the functions of a software module below, it should be understood that such functions are implemented by the processor when executing instructions from that software module.

[0182] In addition, any connection is appropriately referred to as a computer-readable medium. For example, if a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwaves are used to send software from a website, server, or other remote source, the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwaves are included in the definition of medium. Disks and optical discs as used herein include compact discs (CDs), laser discs, optical discs, digital versatile discs (DVDs), floppy disks, and Blu-ray discs, wherein disks generally reproduce data magnetically, while optical discs reproduce data optically with lasers. Therefore, 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). The above combinations should also be included within the scope of computer-readable media.

[0183] Thus, certain aspects may include a computer program product for performing the operations presented herein. For example, such a computer program product may include a computer-readable medium having stored thereon (and / or encoded thereon) instructions, the instructions being executable by one or more processors to perform the operations described herein, for example, for performing the operations described herein and in Figure 4 and / or Figure 5 Instructions for the operations shown in the figure.

[0184] In addition, it should be understood that the components and / or other appropriate units for performing the methods and techniques described herein can be downloaded and / or otherwise obtained by the user terminal and / or base station as needed. For example, such a device can be coupled to a server to facilitate the transmission of the components for performing the methods described herein. Alternatively, the various methods described herein can be provided via a storage component (e.g., RAM, ROM, a physical storage medium such as a compact disc (CD) or a floppy disk, etc.) so that the user terminal and / or base station can obtain the various methods when the storage component is coupled to or provided to the device. In addition, any other suitable technology for providing the methods and techniques described herein to a device can be utilized.

[0185] It should be understood that the claims are not limited to the precise configuration and components described above, and that various modifications, changes, and variations may be made in the arrangement, operation, and details of the methods and apparatus described above without departing from the scope of the claims.

Claims

1. A method for wireless communication by a user equipment (UE), comprising: receiving a first indication of which one or more types of beam failure recovery response (BFRR) messages to monitor; performing beam failure detection BFD of a beam pair link BPL associated with a secondary cell Scell ​​of the base station BS; Sending a beam failure recovery request (BFRQ) message in another cell of the BS, where the BFRQ message includes a second indication of a candidate recovery beam for the Scell; starting a timer based on sending the BFRQ message; monitoring one or more indicated types of BFRR messages, wherein the indicated one or more types include a deactivation command for the Scell; determining whether to resend the BFRQ message in another cell based on whether the indicated one or more types of BFRR messages are received before expiration of the timer; and When it is determined that the indicated one or more types of BFRR messages are not received before the timer expires, the BFRQ message is resent in the other cell.

2. The method according to claim 1, wherein The indicated type or types also include: A new transmission configuration indicator TCI state of the Scell ​​is activated or reconfigured; Transmission of the candidate beam for the Scell ​​is resumed using the candidate beam for the Scell.

3. The method according to claim 2, wherein: A new TCI state activation or reconfiguration for the Scell ​​is received in a media access control MAC control element CE on a physical downlink shared channel PDSCH in the other cell.

4. The method according to claim 2, wherein: A new TCI state activation or reconfiguration for the Scell ​​is received in the other cell.

5. The method according to claim 2, wherein: The transmission using the candidate recovery beam for the Scell ​​is a Physical Downlink Control Channel (PDCCH).

6. The method according to claim 2, wherein: The transmission using the candidate recovery beam for the Scell ​​is sent in predefined resources.

7. The method according to claim 2, wherein: The transmission using the candidate recovery beam for the Scell ​​is sent in resources indicated to the UE.

8. The method according to claim 7, wherein: The resources are indicated to the UE using Radio Resource Control (RRC) signaling.

9. The method according to claim 2, further comprising: and monitoring resources used for the transmission using the candidate recovery beam for the Scell ​​within a period of time after sending the BFRQ message.

10. The method according to claim 9, wherein: The monitoring includes setting a receive beam of the UE to receive the candidate recovery beam for the Scell.

11. The method according to claim 1, wherein The deactivation command is received in a Medium Access Control (MAC) Control Element (CE) on a Physical Downlink Shared Channel (PDSCH) in the other cell.

12. The method according to claim 1, wherein The deactivation command is received in the other cell.

13. A method for wireless communication by a base station BS, comprising: sending a first indication of which one or more types of beam failure recovery response (BFRR) messages to monitor; receiving a beam failure recovery request (BFRQ) message from a user equipment (UE), the BFRQ message including a second indication of a candidate recovery beam of a secondary cell (Scell) of the UE, wherein the BFRQ message is received in another cell; and In response to the BFRQ message, a BFRR message of the indicated one or more types is sent to the UE, wherein the indicated one or more types include a deactivation command for the Scell.

14. The method according to claim 13, wherein The indicated type or types also include: A new transmission configuration indicator TCI state of the Scell ​​is activated or reconfigured; Transmission of the candidate beam for the Scell ​​is resumed using the candidate beam for the Scell.

15. The method according to claim 14, wherein A new TCI state activation or reconfiguration for the Scell ​​is sent in a media access control MAC control element CE on a physical downlink shared channel PDSCH in the other cell.

16. The method according to claim 14, wherein A new TCI state activation or reconfiguration for the Scell ​​is sent in the other cell.

17. The method according to claim 14, wherein: The transmission using the candidate recovery beam for the Scell ​​is a Physical Downlink Control Channel (PDCCH).

18. The method according to claim 14, wherein The transmission using the candidate recovery beam for the Scell ​​is sent in predefined resources.

19. The method according to claim 14, wherein The transmission using the candidate recovery beam for the Scell ​​is sent in resources indicated to the UE.

20. The method according to claim 19, wherein The resources are indicated to the UE using Radio Resource Control (RRC) signaling.

21. The method according to claim 13, wherein The deactivation command is sent in the other cell in a Medium Access Control (MAC) Control Element (CE) on a Physical Downlink Shared Channel (PDSCH).

22. The method according to claim 13, wherein The deactivation command is sent in the other cell.

23. A user equipment (UE), comprising: Memory; as well as a processor communicatively coupled to the memory, the processor configured to: receiving a first indication of which one or more types of beam failure recovery response (BFRR) messages to monitor; performing beam failure detection BFD of a beam pair link BPL associated with a secondary cell Scell ​​of the base station BS; Sending a beam failure recovery request (BFRQ) message in another cell of the BS, where the BFRQ message includes a second indication of a candidate recovery beam for the Scell; starting a timer based on sending the BFRQ; monitoring one or more indicated types of BFRR messages, wherein the indicated one or more types include a deactivation command for the Scell; determining whether to resend the BFRQ message in the other cell based on whether the indicated one or more types of BFRR messages are received before expiration of the timer; and When it is determined that the indicated one or more types of BFRR messages are not received before the timer expires, the BFRQ message is resent in the other cell.

24. The UE according to claim 23, wherein: The indicated type or types also include: A new transmission configuration indicator TCI state of the Scell ​​is activated or reconfigured; Transmission of the candidate beam for the Scell ​​is resumed using the candidate beam for the Scell.

25. The UE according to claim 24, wherein: A new TCI state activation or reconfiguration for the Scell ​​is received in a media access control MAC control element CE on a physical downlink shared channel PDSCH in the other cell.

26. The UE according to claim 24, wherein: A new TCI state activation or reconfiguration for the Scell ​​is received in the other cell.

27. The UE according to claim 24, wherein: The transmission using the candidate recovery beam for the Scell ​​is a Physical Downlink Control Channel (PDCCH).

28. The UE according to claim 24, wherein: The transmission using the candidate recovery beam for the Scell ​​is sent in predetermined resources.

29. A base station BS, comprising: Memory; as well as a processor communicatively coupled to the memory, the processor configured to: sending a first indication of which one or more types of beam failure recovery response (BFRR) messages to monitor; receiving a beam failure recovery request (BFRQ) message from a user equipment (UE), the BFRQ message including a second indication of a candidate recovery beam of a secondary cell (Scell) of the UE, wherein the BFRQ message is received in another cell; and In response to the BFRQ message, the indicated one or more types of BFRR messages are sent to the UE, wherein the indicated one or more types are deactivation commands for the Scell.

30. A computer-readable medium having program instructions stored thereon, wherein the program instructions are executable by one or more processors of a user equipment (UE) to cause the processors to perform the method according to any one of claims 1 to 12.

31. A computer-readable medium having program instructions stored thereon, wherein the program instructions are executable by one or more processors of a base station BS to cause the processors to perform the method according to any one of claims 13 to 22.

32. A computer program product comprising computer-readable instructions, wherein when the computer-readable instructions are executed by one or more processors of a user equipment (UE), the processors are caused to perform the method according to any one of claims 1 to 12.

33. A computer program product comprising computer-readable instructions, which, when executed by one or more processors of a base station (BS), cause the processors to perform the method according to any one of claims 13 to 22.

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