Method for Transmitting / Receiving Point (TRP) Eigenbeam Failure Recovery (BFR) for Single Downlink Control Information (DCI) Mode

Abstract

An aspect is described for a user equipment (UE) comprising a transceiver configured to enable wireless communication with a first transmission / reception point (TRP) and a second TRP, and a processor communicatively coupled to the transceiver. The UE is in a multi-TRP mode. The processor is configured to perform a first beam failure detection (BFD) procedure for the first TRP and a second BFD procedure for the second TRP. The processor is further configured to perform a first beam failure recovery (BFR) procedure for the first TRP according to a result of the first BFD procedure and a second BFR procedure for the second TRP according to a result of the second BFD. The processor is further configured to receive a configuration message, a BFD configuration, and a BFR configuration. The UE switches to a single-TRP mode upon receiving the configuration message. The processor is further configured to update the first BFD procedure based on the BFD configuration and update the first BFR procedure based on the BFR configuration. Finally, the processor is configured to perform an updated first BFD procedure and an updated first BFR procedure for the first TRP depending on a result of the updated first BFD procedure.

Description

[Technical Field]

[0001] The described aspects generally relate to enhancing beam failure recovery for a single downlink control information (DCI) mode. Summary of the Invention

[0002] Some aspects of the present disclosure relate to apparatus and methods for implementing beam failure recovery (BFR) enhancements for a single downlink control information (DCI) mode for 3rd Generation Partnership Project (3GPP) Release 15 (Rel-15), Release 16 (Rel-16), Release 17 (Rel-17), and / or other 3GPP releases that support BFR. For example, systems and methods for implementing transmit / receive point (TRP)-specific BFR are provided.

[0003] Some aspects of the present disclosure relate to a user equipment (UE) comprising: a transceiver configured to enable wireless communication with a first transmission / reception point (TRP) and a second TRP; and a processor communicatively coupled to the transceiver. The processor is configured to perform a first beam failure detection (BFD) procedure for the first TRP and a second BFD procedure for the second TRP. The processor is further configured to perform a first beam failure recovery (BFR) procedure for the first TRP depending on a result of the first BFD procedure and a second BFR procedure for the second TRP depending on a result of the second BFD procedure. The processor is further configured to receive a configuration message, a BFD configuration, and a BFR configuration. Upon receiving the configuration message, the UE switches from a multi-TRP mode to a single-TRP mode. The processor is further configured to update the first BFD procedure based on the BFD configuration and update the first BFR procedure based on the BFR configuration. Finally, the processor is configured to perform an updated first BFD procedure and an updated first BFR procedure for the first TRP according to a result of the updated first BFD procedure.

[0004] Some aspects of the present disclosure relate to a method for operating a UE to communicate with a first TRP and a second TRP. The method includes performing a first BFD procedure for the first TRP and a second BFD procedure for the second TRP. The method further includes performing a first BFR procedure for the first TRP according to a result of the first BFD procedure and a second BFR procedure for the second TRP according to a result of the second BFD procedure. The method further includes receiving a configuration message, a BFD configuration, and a BFR configuration, and switching from multi-TRP mode to single-TRP mode upon receiving the configuration message. The method further includes updating the first BFD procedure based on the BFD configuration and updating the first BFR procedure based on the BFR configuration. Finally, the method includes performing an updated first BFD procedure and an updated first BFR procedure for the first TRP according to a result of the updated first BFD procedure.

[0005] Some aspects of the present disclosure relate to a base station comprising: a transceiver configured to enable communication with a UE; and a processor communicatively coupled to the transceiver. The processor is configured to generate a configuration message, a BFD configuration, and a BFR configuration. The processor is further configured to transmit the configuration message, the BFD configuration, and the BFR configuration to the UE.

[0006] This Summary of the Invention is provided merely for the purpose of illustrating some aspects to provide an understanding of the subject matter described herein. Accordingly, the above features are merely examples and should not be construed as narrowing the scope or spirit of the subject matter in this disclosure. Other features, aspects, and advantages of the present disclosure will become apparent from the following Detailed Description, Figures, and Claims. [Brief explanation of the drawings]

[0007] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate the present disclosure and, together with the description, further serve to explain the principles of the present disclosure and to enable one skilled in the art(s) to make and use the present disclosure.

[0008] [Figure 1] FIG. 1 illustrates an example system implementing transmit / receive point (TRP) eigenbeam failure recovery (BFR) in accordance with certain aspects of the present disclosure.

[0009] [Figure 2] FIG. 1 is a block diagram of an example system of an electronic device for TRP-specific BFR, according to some aspects of the present disclosure.

[0010] [Figure 3] FIG. 1 illustrates an example method for beam failure detection (BFD) and beam failure recovery (BFR) procedures when switching between multi-TRP mode and single-TRP mode, according to an aspect of the present disclosure.

[0011] [Figure 4] FIG. 1 illustrates an example method for an updated BFD procedure, according to an aspect of the present disclosure.

[0012] [Figure 5] FIG. 1 illustrates an exemplary method for an updated BFR procedure, according to an aspect of the present disclosure.

[0013] [Figure 6] FIG. 1 illustrates an example method for coexistence of UE-specific BFR and TRP-specific BFR for beam failure events, according to an aspect of the present disclosure.

[0014] [Figure 7] FIG. 1 illustrates an example method for coexistence of UE-specific BFR and TRP-specific BFR for multiple beam failure events, according to an aspect of the present disclosure.

[0015] [Figure 8] FIG. 1 illustrates an example method for a base station to configure a TRP-specific BFR, according to an aspect of the present disclosure.

[0016] [Figure 9] FIG. 1 illustrates an exemplary computer system for implementing some aspects of the present disclosure or portions thereof.

[0017] The present disclosure is described with reference to the accompanying drawings, in which like reference numbers generally indicate identical or functionally similar elements. Additionally, the left-most digit(s) of a reference number generally identifies the drawing in which the reference number first appears. DETAILED DESCRIPTION OF THE INVENTION

[0018] Some aspects of the present disclosure include apparatus and methods for implementing beam failure recovery (BFR) enhancements for single downlink control information (DCI) modes for Third Generation Partnership Project (3GPP) Release 15 (Rel-15), Release 16 (Rel-16), Release 17 (Rel-17), and / or other 3GPP releases. For example, systems and methods are provided for implementing transmit / receive point (TRP)-specific BFR designs.

[0019] According to some aspects, a user equipment (UE) may operate in accordance with Release 15 (Rel-15), Release 16 (Rel-16), and / or Release 17 (Rel-17) for digital cellular networks defined by 3GPP, and / or New Radio (NR) for fifth-generation (5G) wireless technology, and the UE may support UE-specific BFR. For example, the UE connects with a first TRP via one or more beams. The one or more beams correspond to one or more control resource sets (CORESETs). The UE performs a beam failure detection (BFD) procedure for the first TRP. For example, the UE monitors and detects the status of the one or more beams by detecting a block error rate (BLER) of one or more BFD reference signals (RSs) quasi-co-located (QCLed) with the one or more CORESETs. In some aspects, the BFD RSs include synchronization signal block (SSB) signals and / or channel state information reference signals (CSI-RSs). If the BLER corresponding to a beam falls below a threshold, the UE detects a beam failure. In some aspects, the UE determines that a beam has failed after detecting a predetermined number of beam failures for the beam. In some aspects, the UE declares a beam failure event after determining that all of one or more beams have failed. In such a case, the UE identifies a new candidate beam whose Layer 1 Reference Signal Received Power (L1-RSRP) exceeds a power threshold. In some aspects, the UE performs a BFR procedure for the first TRP. For example, upon detecting a beam failure event, the UE reports the beam failure event and the new candidate beam to the base station via a Beam Failure Recovery Request (BFRQ). In some aspects, the base station is the first TRP. The UE may send the BFRQ via a MAC Control Element (MAC CE) or via Contention-Based Random Access (CBRA). The base station then sends a Beam Failure Recovery Response (BFRR) to the UE to reconnect with the first TRP based on the new candidate beam. In some aspects, the base station transmits the BFRR to the UE via a scheduled transmission over a physical downlink control channel (PDCCH).The PDCCH uses the same hybrid automatic repeat request (HARQ) process as the physical uplink shared channel (PUSCH) corresponding to the MAC CE. In some aspects, if the base station receives a BFRQ from the UE via CBRA, the base station transmits a BFRR to the UE via a fourth message (Msg4). In other words, the base station transmits the BFRR via a PDCCH associated with a cell radio network temporary identifier (C-RNTI) corresponding to the UE.

[0020] According to some aspects, the UE also connects with a second TRP. In some aspects, the UE operates in a single DCI mode in which the base station schedules a physical downlink shared channel (PDSCH) for both the first TRP and the second TRP via a single DCI. The single DCI mode is also referred to as a multi-TRP mode. In some aspects, the UE operates in a multi-DCI mode in which the base station schedules the PDSCH for the first TRP via the first DCI and the PDSCH for the second TRP via the second DCI. In some aspects, the UE may perform TRP-specific BFR for the first and second TRPs. For example, the UE performs separate BFD and BFR procedures for the first and second TRPs.

[0021] In some aspects, a UE may switch from multi-TRP mode to single-TRP mode. For example, the UE may decide to drop the second TRP by refraining from communicating user data to or from the second TRP. The UE may decide to drop the second TRP based on data traffic conditions, such as packet delivery rate. The UE may also decide to drop the second TRP for power efficiency or other reasons. In some aspects, a base station instructs the UE to switch between multi-TRP mode and single-TRP mode. For example, the base station transmits a MAC CE to the UE to instruct the UE whether the UE should be in multi-TRP mode or single-TRP mode. In some aspects, the MAC CE transmitted by the base station includes a transmission configuration indicator (TCI). The UE may determine that a code point in the TCI maps to two TCI states and switch to multi-TRP mode. Conversely, the UE may determine that a code point in the TCI maps to one TCI state and switch to single-TRP mode.

[0022] FIG. 1 illustrates an example system 100 implementing a TRP-specific BFR design according to some aspects of the present disclosure. The example system 100 is provided for illustrative purposes only and does not limit aspects of the disclosure. The system 100 may include, but is not limited to, a UE 102, a TRP 104, a TRP 106, and a TRP 108. The UE 102 may be implemented as an electronic device configured to operate based on a variety of wireless communication techniques. These techniques may include, but are not limited to, techniques based on 3rd Generation Partnership Project (3GPP) standards. For example, the UE 102 may include an electronic device configured to operate using one or more 3GPP releases, such as Release 15 (Rel-15), Release 16 (Rel-16), Release 17 (Rel-17), or other 3GPP releases. The UE 102 may include, but is not limited to, wireless communication devices, smartphones, laptops, desktops, tablets, personal assistants, monitors, televisions, wearable devices, Internet of Things (IoT) devices, and vehicle communication devices. The TRPs 104, 106, and 108 may include one or more nodes configured to operate based on a variety of wireless communication techniques, including, but not limited to, techniques based on 3GPP standards. For example, the TRPs 104, 106, and 108 may include nodes configured to operate using Rel-15, Rel-16, Rel-17, or other 3GPP releases. The TRPs 104, 106, and 108 may include, but are not limited to, base stations, NodeBs, eNodeBs, gNBs, new radio base stations (NR BSs), access points (APs), remote radio heads, relay stations, and others.

[0023] In some aspects, the UE 102 connects with the TRP 104 via communication link 110 and with the TRP 106 via communication link 112. Each of the communication links 110 and 112 includes one or more beams. As described above, the UE 102 is in a multi-TRP mode. In some aspects, the UE 102 may perform TRP-specific BFR, including BFD and BFR procedures for each of the connected TRPs, e.g., the TRP 104 and the TRP 106. For example, the UE 102 performs the BFD procedure for the TRP 104 by monitoring one or more beams of the communication link 110. The UE 102 declares a beam failure event for the TRP 104 when the UE 102 detects that one or more beams of the communication link 110 have failed. After the UE 102 declares the beam failure event for the TRP 104, the UE 102 performs the BFR procedure for the TRP 104. For example, the UE 102 generates a BFRQ for the TRP 104 that identifies one or more new candidate beams and transmits the BFRQ for the TRP 104 to the base station. In some aspects, the base station is the TRP 108. The UE 102 transmits the BFRQ for the TRP 104 to the TRP 108 via communication link 114. In other aspects, the base station is the TRP 104 or the TRP 106. For example, the UE 102 transmits the BFRQ for the TRP 104 to the TRP 106 via communication link 112. The UE 102 may also transmit the BFRQ for the TRP 104 to the TRP 104 via a channel other than communication link 110 after declaring a beam failure event for the TRP 104. For example, the UE 102 may transmit the BFRQ for the TRP 104 to the TRP 104 via a contention-based random access procedure, such as a physical random access channel (PRACH). In some aspects, upon receiving the TRP104 BFRQ, the base station generates a TRP104 BFRR and transmits the TRP104 BFRR to the UE 102. The TRP104 BFRR may confirm one or more new candidate beams. The TRP104 BFRR may reject one or more new candidate beams and identify a different set of one or more new candidate beams. After receiving the TRP104 BFRR, the UE 102 completes the TRP104 BFR procedure by recovering the communication link 110 via the one or more new candidate beams.In some aspects, if the UE 102 does not receive a BFRR in the TRP 104 within a predetermined retransmission period, the UE 102 repeats transmitting a BFRQ in the TRP 104 to the base station.

[0024] In some aspects, the UE 102 performs BFD and BFR procedures for the TRP 106 in a manner similar to that described above with respect to the TRP 104. As described above, the UE 102 performs TRP-specific BFR. Thus, the UE 102 performs BFD and BFR procedures for the TRP 106 regardless of the state of the TRP 104. For example, the UE 102 may declare a beam failure event for the TRP 106 even when the UE 102 is still communicating with the TRP 104 via the communication link 112. In other words, the TRP-specific BFR ensures that the UE 102 can communicate with both the TRP 104 and the TRP 106. In some aspects, when both communication links 110 and 112 fail, the UE 102 generates a BFRQ for the TRP 104 and a BFRQ for the TRP 106 and transmits both BFRQs to the base station. Upon receiving the BFRQ, the base station generates and transmits a BFRR for TRP 104 and a BFRR for TRP 106 to the UE 102, commanding the recovery of the communication links 110 and 112. A UE 102 performing a TRP-specific BFR is also referred to as being in a TRP-specific mode.

[0025] In some aspects, the UE 102 may perform UE-specific BFR or may be in a UE-specific mode. In such a case, the UE 102 performs BFD procedures for both the TRP 104 and the TRP 106. For example, the UE 102 monitors one or more beams of the communication link 110 and one or more beams of the communication link 112. The UE 102 declares a beam failure event for the UE 102 when one or more beams of the communication link 110 and one or more beams of the communication link 112 fail. In other words, the UE 102 does not declare a beam failure event for the UE 102 if the UE 102 can still communicate with the TRP 104 or the TRP 106. For example, the UE 102 does not declare a beam failure event for the UE 102 when one or more beams of the communication link 110 fail but one or more beams of the communication link 112 do not fail. In some aspects, after the UE 102 declares a beam failure event for the UE 102, the UE 102 performs a BFR procedure for the UE 102. For example, the terminal 102 generates a BFRQ for the terminal 102 and then transmits the BFRQ for the terminal 102 to the base station. In some aspects, the BFRQ for the UE 102 indicates one or more new candidate beams for the UE 102 that can be used to restore the communication link 110, the communication link 112, or both. Upon receiving the BFRQ for the UE 102, the base station generates and transmits a BFRR for the UE 102 to the UE 102. The BFRR for the UE 102 may confirm, reject, or indicate the replacement of the one or more new candidate beams for the UE 102, as similarly described above. The BFRR for the UE 102 may also partially confirm the one or more new candidate beams for the UE 102. For example, the BFRQ for the UE 102 indicates a first beam and a second beam. The UE 102 may recover communication link 110 using a first beam and recover communication link 112 using a second beam. The BFRR of the UE 102 may confirm the first beam but reject the second beam. In other words, based on the BFRR of the UE 102, the UE 102 may recover communication link 110 but not communication link 112. In some aspects, the BFFR of the UE 102 confirms the second beam but rejects the first beam, such that the UE 102 recovers communication link 112 but not communication link 110.

[0026] According to some aspects, the UE 102 switches from multi-TRP mode to single-TRP mode. For example, the UE 102 drops the TRP 104 by refraining from communicating user data to or from the TRP 104. In some aspects, the UE 102 updates the BFD and BFR procedures for the TRPs 104 and 106. For example, the UE 102 continues to monitor the communication link 112 but updates the BFD procedure of the TRP 104 to stop generating a BFRQ for the TRP 104. The UE 102 may also update the BFR to stop transmitting additional BFRQs if a BFRR is not received within a predetermined retransmission period. Details of updating the BFD and BFR procedures are disclosed below in FIG. 3. In some aspects, the UE 102 conserves energy by updating the BFD and BFR procedures.

[0027] According to some aspects, the UE 102 can be in only one of the TRP-specific mode and the UE-specific mode at a given time for a component carrier. In other aspects, the UE 102 can be in both the TRP-specific mode and the UE-specific mode simultaneously. That is, the TRP-specific BFR and the UE-specific BFR can coexist. In some aspects, the UE 102 uses a set of BFD RSs for BFD procedures in both the TRP-specific mode and the UE-specific mode. In such a case, the UE 102 performs a constant BFD procedure based on the set of BFD RSs in both the multi-TRP mode and the single-TRP mode. For example, after the UE 102 switches from the multi-TRP mode to the single-TRP mode, the UE 102 continues the constant BFD procedure using the set of BFD RSs. In some aspects, the UE 102 detects a beam failure event and determines the status of the beam failure event based on the constant BFD procedure. For example, the communication link 110 includes first and second beams, and the communication link 112 includes third and fourth beams. If the beam failure event indicates that the first and second beams have failed, the UE 102 determines that the status of the beam failure event is a TRP-specific beam failure event for the TRP 104. In such a case, the UE 102 ignores the beam failure event if the UE 102 is in single-TRP mode after dropping the TRP 104. On the other hand, if the UE 102 is in multi-TRP mode, the UE 102 performs a TRP-specific BFR for the TRP 104. For example, the UE 102 generates and transmits a BFRQ for the TRP 104 to the base station. In some aspects, the beam failure event indicates that the first, second, third, and fourth beams have failed. The UE 102 determines that the status of the beam failure event is a UE-specific beam failure event. In such a case, the UE 102 performs the UE 102 BFR procedure in a UE-specific mode, or performs the TRP 104 BFR procedure and the TRP 106 BFR procedure in a TRP-specific mode. In some aspects, the base station instructs the UE 102 to perform a BFR procedure for the UE 102 or to perform a BFR procedure for the TRP 104 and a BFR procedure for the TRP 106.For example, the base station instructs the UE 102 by sending a MAC CE to the UE 102 .

[0028] In some aspects, the UE 102 uses a first set of BFD RSs for BFD procedures in a TRP-specific mode and a second set of BFD RSs for BFD procedures in a UE-specific mode. In such a case, the UE 102 may detect multiple beam failure events. For example, the UE 102 may detect a UE-specific beam failure event for the UE 102 and a TRP-specific beam failure event for the TRP 104. The UE 102 may trigger a BFRQ based on priority. For example, the UE 102's UE-specific beam failure event has a high priority, the TRP-specific beam failure event for the TRP 104 has a medium priority, and the TRP-specific beam failure event for the TRP 106 has a low priority. Thus, in this case, the UE 102 triggers its BFRQ procedure. In some aspects, the UE 102 triggers multiple BFRQs based on the capabilities of the UE 102.

[0029] 2 is a block diagram of an example system 200 of electronic devices implementing TRP-specific BFR in accordance with some aspects of the present disclosure. System 200 may be any of the electronic devices of system 100 (e.g., UE 102 and TRPs 104, 106, and 108). System 200 includes a processor 210, one or more transceivers 220, a communications infrastructure 240, memory 250, an operating system 252, an application 254, and one or more antennas 260. The illustrated system is provided as an example portion of system 200, which may include other circuit(s) and subsystem(s). Also, while the components of system 200 are illustrated as separate components, aspects of the present disclosure may include any combination of these components, e.g., fewer or more components.

[0030] Memory 250 may include random access memory (RAM) and / or cache, and may include control logic (e.g., computer software) and / or data. Memory 250 may also include other storage devices or memories. According to some examples, operating system 252 may be stored in memory 250. Operating system 252 may manage the transfer of data from memory 250 and / or one or more applications 254 to processor 210 and / or one or more transceivers 220. In some examples, operating system 252 maintains one or more network protocol stacks (e.g., Internet protocol stack, cellular protocol stack, etc.), which may include multiple logic layers. At a corresponding layer of a protocol stack, operating system 252 includes control mechanisms and data structures for performing functions associated with that layer.

[0031] According to some examples, applications 254 may be stored in memory 250. Applications 254 may include applications (e.g., user applications) used by wireless system 200 and / or a user of wireless system 200. Applications in applications 254 may include applications such as, but not limited to, Siri, FaceTime®, radio streaming, video streaming, remote control, and / or other user applications.

[0032] The system 200 may also include a communications infrastructure 240. The communications infrastructure 240 provides communication between, for example, the processor 210, the one or more transceivers 220, and the memory 250. In some implementations, the communications infrastructure 240 may be a bus.

[0033] Processor 210, alone or in conjunction with instructions stored in memory 250, performs operations that enable system 200 of system 100 to implement mechanisms for BFR enhancement for a single DCI mode, as described herein. Alternatively or additionally, processor 210 may be "hard-coded" to implement mechanisms for BFR enhancement for a single DCI mode, as described herein.

[0034] The one or more transceivers 220 transmit and receive communication signals and support mechanisms for BFR enhancements for a single DCI mode. Additionally, the one or more transceivers 220 transmit and receive communication signals that support mechanisms for measuring communication links, generating and transmitting system information, and receiving system information. According to some aspects, the one or more transceivers 220 may be coupled to an antenna 260 to transmit and receive communication signals wirelessly. The antenna 260 may include one or more antennas, which may be of the same or different types. The one or more transceivers 220 enable the system 200 to communicate with other devices, which may be wired and / or wireless. In some examples, the one or more transceivers 220 may include processors, controllers, radios, sockets, plugs, buffers, and similar circuits / devices used for connecting to and communicating in a network. According to some examples, the one or more transceivers 220 include one or more circuits for connecting to and communicating in a wired and / or wireless network.

[0035] According to some aspects of the present disclosure, one or more transceivers 220 may include a cellular subsystem, a WLAN subsystem, and / or a Bluetooth subsystem, each including their own radio transceiver and protocol(s), as would be understood by one of ordinary skill in the art based on the discussion provided herein. In some implementations, one or more transceivers 220 may include more or fewer systems for communicating with other devices.

[0036] In some examples, the one or more transceivers 220 may include one or more circuits (including a WLAN transceiver) for enabling connection(s) and communication over a WLAN network, such as, but not limited to, a network based on the standards set forth in IEEE 802.11.

[0037] Additionally or alternatively, one or more transceivers 220 may include one or more circuits (including a Bluetooth transceiver) for enabling connection and communication based on, for example, the Bluetooth protocol, the Bluetooth Low Energy protocol, or the Bluetooth Low Energy Long Range protocol. For example, transceiver 220 may include a Bluetooth transceiver.

[0038] Additionally, the one or more transceivers 220 may include one or more circuits (including a cellular transceiver) for connecting to and communicating in a cellular network. The cellular network may include, but is not limited to, 3G / 4G / 5G networks such as Universal Mobile Telecommunications System (UMTS), Long Term Evolution (LTE), etc. For example, the one or more transceivers 220 may be configured to operate in accordance with one or more of Rel-15, Rel-16, Rel-17, or other releases of the 3GPP standards.

[0039] As described in more detail below in connection with FIGS. 3-9, the processor 210 may implement different mechanisms for TRP-specific BFR, as described with respect to the system 100 of FIG.

[0040] FIG. 3 illustrates an example method 300 for BFD and BFR procedures when switching between multi-TRP mode and single-TRP mode. For convenience and without limitation, FIG. 3 may be illustrated with reference to elements of FIGS. 1, 2, and 9. Method 300 may represent the operation of an electronic device (e.g., UE 102 and TRPs 104, 106, and 108 of FIG. 1) implementing BFD and BFR procedures. Example method 300 may also be performed by system 200 of FIG. 2 and controlled or performed by processor 210 and / or computer system 900 of FIG. 9. However, method 300 is not limited to the specific aspects illustrated in these figures, and other systems may be used to perform the method, as will be understood by those skilled in the art. It should be understood that not all operations are required, and operations may not be performed in the same order as illustrated in FIG. 3.

[0041] At 302, the UE 102 connects with the TRP 104 and the TRP 106. Thus, the UE 102 is in multi-TRP mode. In some aspects, the UE 102 enters the multi-TRP mode based on a request from an application in the UE 102, such as application 254 in FIG. 2. In some aspects, the UE 102 enters the multi-TRP mode based on a command from a base station, which can be the TRP 104, the TRP 106, or the TRP 108.

[0042] At 304, the UE 102 performs the BFD procedure of the TRP 104 and the BFD procedure of the TRP 106. As described above, the UE 102 monitors the communication links 110 and 112. For example, the UE 102 monitors one or more beams of the communication link 110 and one or more beams of the communication link 112.

[0043] At 306, the UE 102 determines and declares a beam failure event. For example, the UE 102 declares a beam failure event for the TRP 104 if one or more beams of the communication link 110 fail. In such a case, control transfers to 308. Similarly, a beam failure event can be declared for the TRP 106.

[0044] At 308, the UE 102 performs a BFR procedure for the TRP 104. For example, the UE 102 generates a BFRQ for the TRP 104 and transmits the BFRQ for the TRP 104 to the base station. In some aspects, the BFRQ for the TRP 104 identifies one or more new candidate beams for the communication link 110. The UE 102 then receives a BFRR for the TRP 104 from the base station. The BFRR for the TRP 104 identifies one or more confirmed candidate beams. In some aspects, the one or more confirmed candidate beams are different from the one or more new candidate beams. Upon receiving the BFRR for the TRP 104, the UE 102 uses the one or more confirmed candidate beams to restore the communication link 110. Control then returns to 304, where the UE 102 continues to monitor the communication links 110 and 112. A BFR procedure may be performed for the TRP 106 in a similar manner.

[0045] Referring back to 306, if the UE 102 does not declare a beam failure event, control transfers to 310.

[0046] At 310, the UE 102 determines whether to switch to single-TRP mode. In some aspects, the UE 102 decides to switch based on an instruction from a base station. For example, the base station transmits a configuration message to the UE 102 via a MAC CE. In some aspects, the configuration message is in the form of a TCI. For example, the UE 102 may determine that a code point of the TCI maps to two TCI states and switch to multi-TRP mode. Alternatively, the UE 102 may determine that a code point of the TCI maps to one TCI state and switch to single-TRP mode. In other aspects, the MAC CE includes a switch indicator. For example, the switch indicator is a binary bit indicating single-TRP mode or multi-TRP mode. If the UE 102 determines not to switch to single-TRP mode, control returns to 302. On the other hand, if the UE 102 determines to switch to single-TRP mode, control transfers to 312.

[0047] At 312, the UE 102 drops one TRP, such as the TRP 104, to switch to a single-TRP mode by refraining from communicating user data with the TRP. In some aspects, the UE 102 continues to receive an RS from the TRP 104 after dropping the TRP 104. The UE 102 uses the RS received from the TRP 104 to monitor one or more beams of the communication link 110. In other words, the UE 102 monitors the communication link 110 for future use after dropping the TRP 104. In some aspects, the UE 102 refrains from communicating any data, including an RS, with the TRP 104. In such a case, the UE 102 monitors one or more beams by receiving an alternative RS from a TRP other than the TRP 104, and the alternative RS is QCL'd with one or more beams of the communication link 110.

[0048] At 314, the UE 102 updates the BFD and BFR procedures. In some aspects, the UE 102 updates the BFD procedures of the TRP 104 and the TRP 106 to one of five BFD options disclosed below.

[0049] BFD Option 1: The UE 102 stops the BFD procedure of the TRP 104 and resets the BFD counter of the TRP 104. In other words, the UE 102 stops monitoring the communication link 110 when the TRP 104 is dropped. In some aspects, the UE 102 declares a beam failure event based on the BFD counter of the TRP 104. For example, the BFD counter of the TRP 104 includes a number of failures for each of one or more beams of the communication link 110. The number of beam failures is incremented by one when the UE 102 detects a beam failure. When the number of beam failures reaches a predetermined failure threshold, the UE 102 determines that the beam has failed. As described above, the UE 102 declares a beam failure event of the TRP 104 when all of one or more beams of the communication link 110 fail. In such a case, each of the one or more beams has reached a predetermined failure threshold. Thus, when the UE 102 drops the TRP 104, it erases its record of one or more beams of the communication link 110.

[0050] BFD Option 2: The UE 102 stops the BFD procedures of the TRP 104 but maintains the BFD counters of the TRP 104. Thus, the UE 102 stops monitoring the communication link 110. However, the UE 102 may use the BFD counters of the TRP 104 when the UE 102 returns to multi-TRP mode.

[0051] BFD Option 3: The UE 102 continues the BFD procedure for the TRP 104 but suspends the BFRQ for the TRP 104. For example, the UE 102 continues to monitor the communication link 110 and may declare a beam failure event for the TRP 104 if one or more beams of the communication link 110 fail. However, the UE 102 does not generate or transmit the BFRQ for the TRP 104. The UE 102 generates and transmits the BFRQ for the TRP 104 when it returns to the multi-TRP mode. In other words, the UE 102 maintains the BFRQ procedure for the TRP 104 until the UE 102 switches to the multi-TRP mode.

[0052] BFD Option 4: The UE 102 continues the BFD procedure of the TRP 104 without any restrictions on the BFRQ procedure of the TRP 104. For example, the UE 102 continues to monitor the communication link 110 and triggers the BFRQ of the TRP 104 to initiate the BFR procedure of the TRP 104 when necessary.

[0053] BFD Option 5: The UE 102 executes BFD Option 3 or BFD Option 4, as disclosed above, within a first period of time after switching to single-TRP mode. In some aspects, the first period of time is a transition period. The UE 102 monitors the communication link 110 if the UE 102 switches to multi-TRP mode within the transition period. Upon expiration of the first period of time, the UE 102 executes BFD Option 2, as described above, within a second period of time. Upon expiration of the second period of time, the UE 102 executes BFD Option 1, as described above. In some aspects, the UE 102 returns to multi-TRP mode before the first period of time expires. In such a case, the UE 102 may update the first period of time to be the remaining time of the first period. Similarly, if the UE 102 returns to multi-TRP mode before the second period of time expires, the UE 102 may update the second period of time to be the remaining time of the second period.

[0054] In some aspects, the UE 102 updates the BFD procedure of the TRP 104 as instructed by the base station. For example, the base station transmits a BFD configuration to the UE 102. The BFD configuration indicates a selected BFD option. The BFD configuration also includes first and second time periods. In some aspects, the base station transmits the BFD configuration via higher layer signaling. For example, the base station transmits the BFD configuration via RRC signaling or MAC CE. In some aspects, the MAC CE includes a field for TCI activation to indicate the selected BFD option. The UE 102 may also determine the selected BFD option based on whether the TCI state of the CORESET changes after switching to single-TRP mode. For example, the CORESET corresponds to the TRP 104. If the TCI state of the CORESET changes after the UE 102 switches to single-TRP mode by dropping the TRP 104, the UE 102 selects BFD option 1. If the TCI state of CORESET does not change, the UE 102 selects BFD option 4. In some aspects, the base station may transmit the BFD configuration via a DCI indicating the selected BFD option. For example, the DCI may be a Format 1_1 DCI or a Format 1_2 DCI that includes a field to indicate the selected BFD option.

[0055] In some aspects, the UE 102 updates the BFD procedure of the TRP 106 to be the same as the BFD procedure of the TRP 104. In other aspects, the UE 102 updates the BFD procedure of the TRP 106 similar to the BFD procedure of the TRP 104 disclosed above. For example, the BFD configuration includes a selected BFD for the TRP 104 and a selected BFD option for the TRP 106. In some aspects, the BFD configuration may set the first period and the second period of the TRP 106 to be different from those of the TRP 104, as disclosed in BFD option 5 above. In some aspects, the UE 102 may report to the base station the maximum durations of the first and second periods that it supports.

[0056] In some aspects, the UE 102 updates the BFR procedure of the TRP 104 to one of four BFR options disclosed below.

[0057] BFR Option 1: The UE 102 stops the BFR procedure for the TRP 104. If the UE 102 started the BFR procedure for the TRP 104 before switching to single-TRP mode, the UE 102 terminates the BFR procedure for the TRP 104 and considers the BFR procedure for the TRP 104 completed. For example, the UE 102 sent a BFRQ for the TRP 104 to the base station before switching to single-TRP mode, and the UE 102 ignores the BFRR for the TRP 104 received from the base station.

[0058] BFR Option 2: The UE 102 partially suspends the BFR procedure for the TRP 104. For example, if the UE 102 sent a BFRQ for the TRP 104 to the base station before switching to single-TRP mode, the UE 102 processes the BFRR for the TRP 104 received from the base station. However, the UE 102 does not send any additional BFRQ for the TRP 104 before switching to multi-TRP mode. For example, if the UE 102 does not receive a BFRR for the TRP 104 from the base station within a predetermined retransmission period, the UE 102 does not retransmit the BFRQ for the TRP 104.

[0059] BFR Option 3: The UE 102 continues the BFR procedure for the TRP 104. For example, the UE 102 transmits a BFRQ for the TRP 104 to the base station after the UE 102 declares a beam failure event for the TRP 104. If the UE 102 does not receive a BFRR for the TRP 104 from the base station within a predetermined retransmission period, the UE 102 retransmits the BFRQ for the TRP 104.

[0060] BFR Option 4: The UE 102 executes BFR Option 2 or BFR Option 3 disclosed above within a third period after switching to single-TRP mode. When the third period expires, the UE 102 executes BFR Option 1 disclosed above.

[0061] In some aspects, the UE 102 updates the BFR procedure of the TRP 104 as instructed by the base station. For example, the base station transmits a BFR configuration to the UE 102. The BFR configuration indicates a selected BFR option. In some aspects, the BFR configuration also indicates whether to execute BFR option 2 or BFR option 3 within a third period when selecting BFR option 4. The BFR configuration also includes the third period. In some aspects, the base station transmits the BFR configuration via higher layer signaling. For example, the base station transmits the BFR configuration via RRC signaling or MAC CE. In some aspects, the MAC CE includes a field for TCI activation to indicate the selected BFR option. The UE 102 may also determine the selected BFR option based on whether the TCI state of the CORESET changes after switching to single-TRP mode. For example, the CORESET corresponds to the TRP 104. After the UE 102 switches to single-TRP mode by dropping the TRP 104, if the TCI state of CORESET changes, the UE 102 selects BFR option 1. If the TCI state of CORESET does not change, the UE 102 selects BFR option 3. In some aspects, the base station may transmit a BFR configuration via a DCI indicating the selected BFR option. For example, the DCI may be a Format 1_1 DCI or a Format 1_2 DCI that includes a field to indicate the selected BFR option.

[0062] In some aspects, the UE 102 updates the BFR procedure of the TRP 106 to be the same as the BFR procedure of the TRP 104. In other aspects, the UE 102 updates the BFR procedure of the TRP 106 similar to the BFR procedure of the TRP 104 disclosed above. For example, the BFR configuration includes a selected BFR of the TRP 104 and a selected BFR option of the TRP 106. In some aspects, the BFR configuration may set the third period of the TRP 106 to be different from the third period of the TRP 104, as disclosed in BFR option 4 above. In some aspects, the UE 102 may report to the base station the maximum duration of the third period that it supports.

[0063] At 316, the UE 102 executes the updated BFD procedure of the TRP 104 and the updated BFD procedure of the TRP 106. Control may transfer to 322, which is instructed based on the selected BFD option. For example, if the updated BFD procedure of the TRP 104 and the updated BFD procedure of the TRP 106 correspond to BFD option 1 or BFD option 2, control transfers directly to 322, as the UE 102 does not declare a beam failure event in this case. Otherwise, control transfers to 318.

[0064] At 318, the UE 102 determines whether there is a beam failure event based on the updated BFD procedure of the TRP 104 and the updated BFD procedure of the TRP 106. If the UE 102 declares a beam failure event of the TRP 104 or the TRP 106, control passes to 320. Otherwise, control passes to 322.

[0065] At 320, the UE 102 performs an updated BFR procedure for the TRP 104 or the TRP 106. For example, if the UE 102 declared a beam failure event for the TRP 104 at 318, the UE 102 performs an updated BFR procedure for the TRP 104 to restore the communication link 110. Control then returns to 316.

[0066] At 322, the UE 102 determines whether to switch back to multi-TRP mode. Similar to 310, the UE 102 decides to switch based on instructions from the base station. If the UE 102 decides to switch, control passes to 302. Otherwise, control passes to 316.

[0067] FIG. 4 illustrates an exemplary method for an updated BFD procedure. For convenience and without limitation, FIG. 4 may be illustrated with reference to elements of FIGS. 1, 2, and 9. Method 400 may represent the operation of an electronic device (e.g., UE 102 and TRPs 104, 106, and 108 of FIG. 1) implementing a BFD procedure. Example method 400 may also be performed by system 200 of FIG. 2 and controlled or performed by processor 210 and / or computer system 900 of FIG. 9. However, method 400 is not limited to the specific embodiments illustrated in these figures, and other systems may be used to perform the method, as will be understood by those skilled in the art. It should be understood that not all operations are required, and operations may not be performed in the same order as illustrated in FIG. 4. In some aspects, method 400 describes details of BFD option 5 of 314 in FIG. 3.

[0068] At 402, the UE 102 switches to the single-TRP mode by dropping one TRP, such as the TRP 104. In some aspects, the UE 102 switches to the single-TRP mode based on an instruction received from a base station. For example, the base station sends a MAC CE to the UE 102 to instruct the UE 102 to switch to the single-TRP mode. The UE 102 continues to monitor one or more beams of the communication link 110.

[0069] At 404, the UE 102 stops a BFD procedure, such as a BFD procedure of the TRP 104. In some aspects, the UE 102 continues to monitor one or more beams of the communication link 110 during a first period 408, also referred to as a BFD transition period. In some aspects, the length of the first period 408 is predetermined. In other aspects, the base station may configure the length of the first period 408 by sending a BFD configuration to the UE 102. The UE 102 may also adjust the length of the first period 408 based on a request received from an application of the UE 102, such as application 254 of FIG. 2 .

[0070] At 406, the UE 102 resets the BFD counter of the TRP 104 after the second period 410. In some aspects, the length of the second period 410 is predetermined. In other aspects, the base station may configure the length of the second period 410 by sending a BFD configuration to the UE 102. The UE 102 may also adjust the length of the second period 410 based on a request received from an application of the UE 102, such as application 254 of FIG. 2.

[0071] At 412, the UE 102 returns to multi-TRP mode. At 414, the UE 102 resumes the BFD procedures of the TRP 104. In some aspects, 412 is the same as 414. In other words, the UE 102 resumes the BFD procedures of the TRP 104 when it returns to multi-TRP mode. In some aspects, 412 may be triggered any time after 402. For example, 412 may be triggered after 402 and before 404. In such a case, the UE 102 is in the BFD transition period 408 before switching to multi-TRP mode, so the UE 102 does not stop the BFD procedures of the TRP 104. Furthermore, 404 and 406 are not triggered. 412 may also be triggered after 404 and before 406. In such a case, 406 is not triggered. In other words, the UE 102 does not reset the BFD counters. In such a case, 414 may use a BFD counter containing information prior to 402. For example, UE 102 may determine that a beam has failed if UE 102 detects that the BLER corresponding to the beam is below the threshold ten times. UE 102 may detect that the BLER corresponding to the beam is below the threshold nine times prior to 402. In such a case, after returning to multi-TRP mode, UE 102 may determine that a beam has failed if UE 102 detects that the BLER corresponding to the beam is below the threshold once.

[0072] FIG. 5 illustrates an exemplary method for an updated BFR procedure. For convenience and without limitation, FIG. 5 may be illustrated with reference to elements of FIGS. 1, 2, and 9. Method 500 may represent the operation of an electronic device (e.g., UE 102 and TRPs 104, 106, and 108 of FIG. 1) implementing a BFD procedure. Example method 500 may also be performed by system 200 of FIG. 2 and controlled or performed by processor 210 and / or computer system 900 of FIG. 9. However, method 500 is not limited to the specific aspects shown in these figures, and other systems may be used to perform the method, as will be understood by those skilled in the art. It should be understood that not all operations may be required, and that operations may not be performed in the same order as shown in FIG. 5. In some aspects, method 500 describes details of BFR option 4 of 314 of FIG. 3.

[0073] At 502, the UE 102 switches to the single-TRP mode by dropping one TRP, such as the TRP 104. In some aspects, the UE 102 switches to the single-TRP mode based on an instruction received from a base station. For example, the base station sends a MAC CE to the UE 102 to instruct the UE 102 to switch to the single-TRP mode. The UE 102 continues to monitor one or more beams of the communication link 110.

[0074] At 504, the UE 102 stops the BFD procedure, such as the BFD procedure for TRP 104. In some aspects, the UE 102 continues to perform the BFR procedure for TRP 104 during a third period 506, also referred to as a BFR transition period. In some aspects, the length of the third period 506 is predetermined. In other aspects, the base station may configure the length of the third period 506 by sending a BFR configuration to the UE 102. The UE 102 may also adjust the length of the third period 506 based on a request received from an application of the UE 102, such as application 254 of FIG. 2. In some aspects, the UE 102 initiates the BFR procedure for TRP 104 before 504, and the UE 102 terminates the BFR procedure for TRP 104 at 504. For example, the UE 102 transmits a BFRQ for TRP 104 to the base station before 504 but does not receive a BFRR for TRP 104 from the base station before 504. The UE 102 terminates the TRP 104 BFR procedure and ignores any TRP 104 BFRRs received after 504.

[0075] At 510, the UE 102 returns to multi-TRP mode. At 512, the UE 102 resumes the TRP104 BFR procedure. In some aspects, 510 is co-located with 512. In other words, the UE 102 resumes the TRP104 BFR procedure when it returns to multi-TRP mode. In some aspects, 510 may be triggered any time after 502. For example, 510 may be triggered after 502 and before 504. In such a case, the UE 102 continues the TRP104 BFR procedure if initiated before 510. For example, before 510, the UE 102 initiates the TRP104 BFR procedure by sending a TRP104 BFRQ to the base station but does not receive a TRP104 BFRR. The UE 102 waits until a predetermined retransmission period expires to retransmit the TRP104 BFRQ.

[0076] FIG. 6 illustrates an example method for coexistence of UE-specific BFR and TRP-specific BFR for a beam failure event. For convenience and without limitation, FIG. 6 may be illustrated with reference to elements of FIGS. 1, 2, and 9. Method 600 may represent operations of an electronic device (e.g., UE 102 and TRPs 104, 106, and 108 of FIG. 1) implementing a BFD procedure. Example method 600 may also be performed by system 200 of FIG. 2 and controlled or performed by processor 210 and / or computer system 900 of FIG. 9. However, method 600 is not limited to the specific aspects shown in these figures, and other systems may be used to perform the method, as will be understood by those skilled in the art. It should be understood that not all operations may be required, and that operations may not be performed in the same order as shown in FIG. 6.

[0077] At 602, the UE 102 detects a beam failure event. In some aspects, the UE 102 performs a UE-specific BFD procedure and a TRP-specific BFD procedure because the UE 102 is in both a TRP-specific mode and a UE-specific mode. Thus, the UE 102 detects a beam failure event based on either the UE-specific BFD procedure or the TRP-specific BFD procedure.

[0078] At 604, the UE 102 determines the status of the beam failure event. In some aspects, the UE 102 determines that the beam failure event is a TRP-specific beam failure event if the beam failure event indicates that one or more beams of the TRP, e.g., one or more beams of the communication link 110, fail. In such a case, control passes to 606. The UE 102 determines that the beam failure event is a UE-specific beam failure event if the beam failure event indicates that all beams corresponding to the UE 102 fail. In such a case, control passes to 612.

[0079] At 606, the UE 102 determines whether the UE 102 is in single-TRP mode or multi-TRP mode. In some aspects, upon determining single-TRP mode, the UE 102 also determines whether the UE 102 is in a BFD transition period. If the UE 102 is in single-TRP mode, control passes to 608. Otherwise, control passes to 610.

[0080] At 608, the UE 102 ignores the beam failure event and continues the BFD procedure, such as the BFD procedure of the TRP 104. For example, the TRP 104 is dropped and the beam failure event indicates that one or more beams of the communication link 110 fail. In such a case, the UE 102 continues the BFD procedure of the TRP 104. In some aspects, the UE 102 resets the BFD counters of the TRP 104. In some aspects, if the UE 102 detects the beam failure event after the BFD transition period, the UE 102 ignores the beam failure event and stops the BFD procedure.

[0081] At 610, the UE 102 performs a TRP-specific BFR corresponding to the beam failure event. For example, the beam failure event corresponds to the TRP 104. The UE 102 performs the BFR procedure of the TRP 104 to restore the communication link 110.

[0082] At 612, the UE determines whether the UE 102 is in single-TRP mode or multi-TRP mode, similar to that disclosed at 606. If the UE 102 is in single-TRP mode, control passes to 614. Otherwise, control passes to 616. In some aspects, the UE 102 determines to implement UE-specific BFR or TRP-specific BFR based on instructions from a base station. For example, the base station sends a configuration message to the UE 102 via RRC signaling, MAC CE, or DCI. If the configuration message indicates that the UE 102 selects UE-specific BFR, control passes to 614. If the configuration message indicates that the UE 102 selects TRP-specific BFR, control passes to 616.

[0083] At 614, the UE 102 performs UE-specific BFR. As disclosed above, the UE-specific BFR recovers at least one beam for the UE 102. For example, the TRP 104 is dropped. The UE 102 can recover the beam for the communication link 112 to restore the communication link 112.

[0084] At 616, the UE 102 performs TRP-specific BFR. For example, the UE 102 generates and transmits both a BFRQ for TRP 104 and a BFRQ for TRP 106. Upon receiving the BFRQs for TRP 104 and TRP 106, the UE 102 restores the communication links 110 and 112. In some aspects, the UE 102 performs TRP-specific BFR based on instructions from the Base Station. For example, the UE 102 generates multiple BFR capability reports and transmits the multiple BFR capability reports to the base station. The multiple BFR capability reports indicate that the UE 102 can generate and transmit two or more BFRQs. The base station then transmits multiple BFR configurations to the UE 102, enabling the UE 102 to generate and transmit two or more BFRQs. In some aspects, the UE 102 can generate and transmit two or more BFRQs after transmitting the multiple BFR capability reports to the base station without receiving multiple BFR configurations from the base station.

[0085] FIG. 7 illustrates an exemplary method for coexistence of UE-specific BFR and TRP-specific BFR for multiple beam failure events. For convenience and without limitation, FIG. 7 may be illustrated with reference to elements of FIGS. 1, 2, and 9. Method 700 may represent the operation of an electronic device (e.g., UE 102 and TRPs 104, 106, and 108 of FIG. 1) implementing a BFD procedure. Example method 700 may also be performed by system 200 of FIG. 2 and controlled or performed by processor 210 and / or computer system 900 of FIG. 9. However, method 700 is not limited to the specific aspects illustrated in these figures, and other systems may be used to perform the method, as will be understood by those skilled in the art. It should be understood that not all operations may be required, and that operations may not be performed in the same order as illustrated in FIG. 7.

[0086] At 702, the UE 102 detects multiple beam failure events. In some aspects, the UE 102 performs a UE-specific BFD procedure and a TRP-specific BFD procedure because the UE 102 is in both a TRP-specific mode and a UE-specific mode. Furthermore, the UE 102 uses different sets of RSs for the UE-specific BFD procedure and the TRP-specific BFD procedure. Thus, the UE 102 can simultaneously detect multiple beam failure events based on the UE-specific BFD procedure and the TRP-specific BFD procedure.

[0087] At 704, the UE 102 determines whether multiple BFR procedures are enabled. Similar to what is described above, the UE 102 enables multiple BFR procedures by sending multiple BFR capability reports to a base station and receiving multiple BFR configurations from the base station. In some aspects, the UE 102 enables multiple BFR procedures by sending multiple BFR capability reports to a base station without receiving multiple BFR configurations from the base station. If multiple BFR procedures are enabled, control passes to 706. Otherwise, control passes to 708.

[0088] At 706, the UE 102 triggers multiple BFRQs corresponding to the multiple beam failure events. In some aspects, the UE 102 processes multiple BFRRs corresponding to the multiple BFRQs to restore one or more communication links, such as communication links 110 and 112.

[0089] At 708, the UE 102 determines the status of the multiple beam failure events. For example, the multiple beam failure events include first, second, and third beam failure events. The UE 102 determines the first beam failure event as a TRP 104 event if the first beam failure event indicates that one or more beams of the communication link 110 have failed. The UE 102 also determines the second beam failure event as a TRP 106 event if the second beam failure event indicates that one or more beams of the communication link 112 have failed, and determines the third beam failure event as a UE 102 event if the third beam failure event indicates that all beams of the UE 102 have failed.

[0090] At 710, the UE 102 triggers a BFRQ procedure corresponding to one of the multiple beam failure events based on their priority. For example, the third beam failure event has a high priority, the first beam failure event has a medium priority, and the second beam failure event has a low priority. Thus, when the UE 102 detects the first, second, and third beam failure events, the UE 102 triggers a BFRQ of the UE 102 corresponding to the third beam failure event. Similarly, when the UE 102 detects the first and second beam failure events, the UE 102 triggers a BFRQ of the TRP 104. In some aspects, the priorities of the first, second, and third beam failure events are configured by the base station. For example, a configuration message transmitted by the base station indicates the priorities of the first, second, and third beam failure events.

[0091] FIG. 8 illustrates an exemplary method for a base station to configure a TRP-specific BFR. For convenience and without limitation, FIG. 8 may be illustrated with reference to elements of FIGS. 1, 2, and 9. Method 800 may represent the operation of an electronic device (e.g., TRPs 104, 106, and 108 of FIG. 1) that configures a TRP-specific BFR. Exemplary method 800 may also be performed by system 200 of FIG. 2 and controlled or implemented by processor 210 and / or computer system 900 of FIG. 9. However, method 800 is not limited to the specific aspects shown in these figures, and other systems may be used to perform the method, as will be understood by those skilled in the art. It should be understood that not all operations may be required, and that operations may not be performed in the same order as shown in FIG. 8.

[0092] At 802, the base station generates a configuration message. In some aspects, the configuration message instructs the UE 102 to be in multi-TRP mode or single-TRP mode. For example, if the configuration message indicates single-TRP mode, the UE 102 is in multi-TRP mode. Upon receiving the configuration message, the UE 102 switches from multi-TRP mode to single-TRP mode.

[0093] At 804, the base station generates a BFD configuration. In some aspects, the BFD configuration indicates a selected BFD option, as disclosed in FIG. 3. For example, if the BFD configuration indicates that BFD option 5 is the selected BFD option, then upon receiving the BFD configuration, the UE 102 updates the BFD procedures based on BFD option 5. In some aspects, the BFD configuration also includes lengths of the first period and the second period of BFD option 5, as disclosed in FIG. 3.

[0094] At 806, the base station generates a BFR configuration. In some aspects, the BFR configuration indicates a selected BFR option, as disclosed in FIG. 3. For example, if the BFR configuration indicates that BFR option 4 is the selected BFR option, the UE 102, upon receiving the BFR configuration, updates BFR procedures based on BFR option 4. In some aspects, the BFR configuration also includes a third period length for BFR option 4, as disclosed in FIG. 3.

[0095] At 808, the base station transmits the configuration message, the BFD configuration, and the BFR configuration to the UE 102. In some aspects, the base station transmits the configuration message, the BFD configuration, and the BFR configuration via radio resource control (RRC) signaling, a MAC control element (MAC CE), or downlink control information (DCI). In some aspects, the base station transmits the BFD configuration and the BFR configuration before transmitting the configuration message.

[0096] Various aspects may be implemented using one or more computer systems, such as computer system 900 shown in FIG. 9 . Computer system 900 may be any known computer system capable of performing the functions described herein, such as electronic devices 102, 104, 106, 108 of FIG. 1 or electronic device 200 of FIG. 2 . Computer system 900 includes one or more processors (also referred to as central processing units, or CPUs), such as processor 904. Processor 904 is connected to a communications infrastructure 906 (e.g., a bus). Computer system 900 also includes user input / output device(s) 903, such as a monitor, keyboard, pointing device, etc., that communicate with communications infrastructure 906 via user input / output interface(s) 902. Computer system 900 also includes main or primary memory 908, such as random access memory (RAM). Main memory 908 may include one or more levels of cache. Main memory 908 stores control logic (e.g., computer software) and / or data.

[0097] Computer system 900 may also include one or more secondary storage devices or secondary memories 910. Secondary memories 910 may include, for example, a hard disk drive 912 and / or a removable storage device or drive 914. Removable storage drive 914 may be a floppy disk drive, a magnetic tape drive, a compact disk drive, an optical storage device, a tape backup device, and / or any other storage device / drive.

[0098] The removable storage drive 914 may interface with a removable storage unit 918. The removable storage unit 918 includes a computer-usable or computer-readable storage device on which computer software (control logic) and / or data is stored. The removable storage unit 918 may be a floppy disk, magnetic tape, compact disk, DVD, optical storage disk, and / or any other computer data storage device. The removable storage drive 914 reads from and / or writes to the removable storage unit 918 in a well-known manner.

[0099] According to some aspects, secondary memory 910 may include other means, instrumentalities, or techniques for making computer programs and / or other instructions and / or data accessible by computer system 900. Examples of such means, instrumentalities, or techniques may include, for example, removable storage unit 922 and interface 920. Examples of removable storage unit 922 and interface 920 may include a program cartridge and cartridge interface (such as those found in video game devices), a removable memory chip (such as an EPROM or PROM) and associated socket, a memory stick and USB port, a memory card and associated memory card slot, and / or any other removable storage unit and associated interface.

[0100] Computer system 900 may further include a communications or network interface 924. Communications interface 924 enables computer system 900 to communicate and interact with any combination of remote devices, remote networks, remote entities, etc. (individually and collectively referred to by reference numeral 928). For example, communications interface 924 may enable computer system 900 to communicate with remote devices 928 over communications path 926, which may be wired and / or wireless and may include any combination of a LAN, a WAN, the Internet, etc. Control logic and / or data may be transmitted to and from computer system 900 via communications path 926.

[0101] The operations in the aforementioned aspects may be implemented in a wide variety of configurations and architectures. Thus, some or all of the operations in the aforementioned aspects may be performed in hardware, software, or both. In some aspects, a tangible, non-transitory apparatus or article of manufacture is also referred to herein as a computer program product or program storage device that includes a tangible, non-transitory computer-usable or readable medium having control logic (software) stored thereon. This includes, but is not limited to, computer system 900, main memory 908, secondary memory 910, removable storage units 918 and 922, and tangible articles of manufacture embodying any combination of the foregoing. Such control logic, when executed by one or more data processing devices (e.g., computer system 900), causes such data processing devices to operate as described herein.

[0102] Based on the teachings contained herein, it will be apparent to one skilled in the relevant art(s) how to make and use aspects of the present disclosure using data processing devices, computer systems and / or computer architectures other than those shown in Figure 9. In particular, aspects may operate with software, hardware, and / or operating system implementations other than those described herein.

[0103] It is understood that it is the "Detailed Description" section, and not the "Summary" and "Abstract" sections, that are intended to be used to interpret the claims. The Summary and Abstract sections may describe one or more exemplary aspects of the disclosure, but not all of the exemplary aspects of the disclosure, as contemplated by the inventor(s), and therefore, the Summary and Abstract sections are not intended to limit the scope of the disclosure or the appended claims in any way.

[0104] While the present disclosure is described herein with reference to exemplary embodiments for exemplary fields and applications, it should be understood that the present disclosure is not limited to the exemplary embodiments. Other embodiments and variations of the embodiments are possible and are within the scope and spirit of the present disclosure. By way of example, and without limiting the generality of this paragraph, the embodiments are not limited to the software, hardware, firmware, and / or entities shown in the figures and / or described herein. Moreover, the embodiments (whether or not explicitly described herein) have significant utility for fields and applications beyond the examples described herein.

[0105] Aspects have been described herein with the help of functional building blocks that illustrate the implementation of certain functions and their relationships. Boundaries of these functional building blocks have been arbitrarily defined herein for convenience of description. Alternative boundaries may be defined so long as the specified functions and relationships (or their equivalents) are appropriately performed. In addition, alternative aspects may execute functional blocks, steps, operations, methods, etc. using an order different from that described herein.

[0106] References herein to "one embodiment," "one embodiment," "exemplary embodiment," or similar phrases indicate that the described embodiment may include a particular feature, structure, or characteristic, but not all embodiments necessarily include the particular feature, structure, or characteristic. Also, such phrases do not necessarily refer to the same embodiment. Furthermore, when a particular feature, structure, or characteristic is described in the context of one embodiment, it is within the knowledge of one skilled in the relevant art(s) to incorporate such particular feature, structure, or characteristic into other aspects, whether or not explicitly mentioned or described herein.

[0107] The breadth and scope of the present disclosure should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.

[0108] It is understood that use of personally identifiable information should comply with generally recognized privacy policies and practices that meet or exceed industry or government requirements for maintaining user privacy. In particular, personally identifiable information data should be managed and handled in a manner that minimizes the risk of unintended or unauthorized access or use, and the nature of permitted uses should be clearly indicated to users.

[0109] This disclosure contemplates that entities involved in the collection, analysis, disclosure, transmission, storage, or other use of such personal information data will adhere to robust privacy policies and / or privacy practices. Specifically, such entities should implement and consistently use privacy policies and practices that are generally recognized as meeting or exceeding industry or government requirements for maintaining the strict confidentiality of personal information data. Such policies should be easily accessible to users and should be updated as data collection and / or use changes. Personal information from users should be collected for the entity's lawful and legitimate use and should not be shared or sold except for those legitimate uses. Furthermore, such collection / sharing should only be carried out after the user's informed consent is obtained. Furthermore, such entities should consider taking all necessary measures to protect and secure access to such personal information data and to ensure that others with access to the personal information data adhere to their privacy policies and procedures. Furthermore, such entities may submit themselves to third-party assessments to demonstrate their adherence to widely accepted privacy policies and practices. Furthermore, policies and practices should be tailored to the specific types of personal data collected and / or accessed and should comply with applicable laws, regulations, and standards, including jurisdiction-specific considerations. For example, in the United States, the collection of or access to certain health data may be governed by federal and / or state laws, such as the Health Insurance Portability and Accountability Act (HIPAA), while health data in other countries may be subject to other regulations and policies and should be addressed accordingly. Therefore, different privacy practices should be maintained in each country with respect to different types of personal data.

Claims

1. A user equipment (UE), a transceiver configured to enable wireless communication with a first transmission / reception point (TRP) and a second TRP; a processor communicatively coupled to the transceiver, the processor comprising: performing a first beam fault detection (BFD) procedure for the first TRP and a second BFD procedure for the second TRP; performing a first beam failure recovery (BFR) procedure for the first TRP in response to an outcome of the first BFD procedure, and performing a second BFR procedure for the second TRP in response to an outcome of the second BFD procedure; receiving, using the transceiver, a configuration message indicating a switch for the UE from a multi-TRP mode to a single-TRP mode; Using the transceiver, receiving BFD and BFR configurations; switching to the single TRP mode based on the configuration message by refraining from communicating user data to or from the first TRP; updating the first BFD procedure based on the BFD configuration; and updating the first BFR procedure based on the BFR configuration; performing the updated first BFD procedure for the first TRP; performing the updated first BFR procedure for the first TRP depending on a result of the updated first BFD procedure; The UE is configured to:

2. 2. The UE of claim 1, wherein the processor is configured to receive the BFD configuration and the BFR configuration by receiving Radio Resource Control (RRC) signaling, a MAC control element (MAC CE), or a downlink control information (DCI).

3. 2. The UE of claim 1, wherein the processor: updating the second BFD procedure based on the BFD configuration; and updating the second BFR procedure based on the BFR configuration; performing the updated second BFD procedure for the second TRP; performing the updated second BFR procedure for the second TRP depending on a result of the updated second BFD procedure; The UE is configured to:

4. 4. The UE of claim 3, wherein the processor: pausing the first BFD procedure and resetting a BFD counter; pausing the first BFD procedure and continuing the BFD counter; continuing the first BFD procedure and suspending Beam Failure Recovery Request (BFRQ); or continuing the first BFD procedure; The UE is configured to update the first BFD procedure by

5. 4. The UE of claim 3, wherein the processor: pausing the first BFR procedure; continuing the first BFR procedure and suspending a Beam Failure Recovery Request (BFRQ); or continuing said first BFR procedure; The UE is configured to update the first BFR procedure by

6. 4. The UE of claim 3, wherein the processor further comprises: pausing the first BFD procedure when a first period expires, the first period starting after switching to the single-TRP mode, and the BFD configuration indicating a length of the first period; resetting a BFD counter when a second period expires, the second period starting after pausing the first BFD procedure, and the BFD configuration indicating a length of the second period; and configured to update the first BFD procedure by The processor, pausing the first BFR procedure when a third period expires, the third period starting after switching to the single TRP mode, and the BFR configuration indicating a length of the third period; The UE is configured to update the first BFR procedure by

7. 2. The UE of claim 1, wherein the processor: Detecting one or more block error rates (BLERs) of one or more reference signals, the one or more reference signals including a synchronization signal block (SSB) signal and / or a channel state information reference signal (CSI-RS); determining one or more beam failure events based on the one or more BLERs; and The UE is configured to perform the first BFD procedure for the first TRP by

8. 2. The UE of claim 1, wherein the processor further comprises: determining a beam failure event based on the first BFD procedure and the second BFD procedure; Determine a status of the beam failure event, where the status of the beam failure event includes a UE-specific beam failure event or a TRP-specific beam failure event; performing a BFR procedure based on the status of the beam failure event. The UE is configured to:

9. 9. The UE of claim 8, wherein the processor further comprises: determining that the status of the beam failure event indicates a TRP-specific beam failure event corresponding to the second TRP; determining that the UE is in the multi-TRP mode; performing the second BFR procedure for the second TRP; The UE is configured to:

10. 9. The UE of claim 8, wherein the processor further comprises: determining that the status of the beam failure event indicates a UE-specific beam failure event; Triggering TRP-specific beam failure recovery requests (BFRQs) for the first TRP and the second TRP, or UE-specific BFRQs, based on whether the UE is in the multi-TRP mode or the single-TRP mode; The UE is configured to:

11. 2. The UE of claim 1, wherein the processor further comprises: determining a plurality of beam failure events based on the first BFD procedure and the second BFD procedure; Determine a corresponding status of the beam failure event, where the corresponding status of the beam failure event includes a UE-specific beam failure event, a first TRP-specific beam failure event corresponding to the first TRP, or a second TRP-specific beam failure event corresponding to the second TRP; triggering a beam failure recovery request (BFRQ) based on a priority of the corresponding status of the beam failure event; The UE is configured to:

12. 2. The UE of claim 1, wherein the processor further comprises: Generate a plurality of BFR capability reports; transmitting, using the transceiver, the plurality of BFR capability reports to a base station; receiving a plurality of BFR configurations from the base station using the transceiver; determining a plurality of beam obstruction events based on the BFD procedure; triggering a plurality of beam failure recovery requests (BFRQs) based on the plurality of beam failure events; The UE is configured to:

13. 1. A method of operating a user equipment (UE) to communicate with a first transmission / reception point (TRP) and a second TRP, the method comprising: performing a first beam fault detection (BFD) procedure for the first TRP and a second BFD procedure for the second TRP; performing a first beam failure recovery (BFR) procedure for the first TRP in response to a result of the first BFD procedure, and performing a second BFD procedure for the second TRP in response to a result of the second BFD procedure; receiving a configuration message indicating a switch for the UE from a multi-TRP mode to a single-TRP mode; Receiving a BFD configuration and a BFR configuration; switching to the single TRP mode based on the configuration message by refraining from communicating user data to or from the first TRP; updating the first BFD procedure based on the BFD configuration and updating the first BFR procedure based on the BFR configuration; performing the updated first BFD procedure for the first TRP; and performing an updated first BFR procedure for the first TRP in response to a result of the updated first BFD procedure; A method comprising:

14. 14. The method of claim 13, updating the second BFD procedure based on the BFD configuration and updating the second BFR procedure based on the BFR configuration; performing the updated second BFD procedure for the second TRP; and performing an updated second BFR procedure for the second TRP in response to a result of the updated second BFD procedure; The method further comprises:

15. 15. The method of claim 14, wherein the updating of the first BFD procedure comprises: pausing the first BFD procedure and resetting a BFD counter; pausing the first BFD procedure and continuing the BFD counter; continuing the first BFD procedure and suspending Beam Failure Recovery Request (BFRQ); or continuing the first BFD procedure; The method further comprises:

16. 15. The method of claim 14, wherein the updating of the first BFR procedure comprises: pausing the first BFR procedure; continuing the first BFR procedure and suspending a Beam Failure Recovery Request (BFRQ); or continuing said first BFR procedure; The method further comprises:

17. 15. The method of claim 14, The updating of the first BFD procedure includes: pausing the first BFD procedure when a first period expires, the first period starting after switching to the single-TRP mode, and the BFD configuration indicating a length of the first period; resetting a BFD counter when a second period expires, the second period starting after pausing the first BFD procedure, and the BFD configuration indicating a length of the second period; The updating of the first BFR procedure includes: The method further includes pausing the first BFR procedure when a third period expires, the third period starting after switching to the single-TRP mode, and the BFR configuration indicating a length of the third period.

18. 14. The method of claim 13, determining a beam failure event based on the first BFD procedure and the second BFD procedure; determining a status of the beam failure event, the status of the beam failure event including a UE-specific beam failure event or a TRP-specific beam failure event; performing a beam fail reversal procedure based on the status of the beam failure event; and The method further comprises:

19. 14. The method of claim 13, determining a plurality of beam failure events based on the first BFD procedure and the second BFD procedure; Determining a corresponding status of the beam failure event, the corresponding status of the beam failure event including a UE-specific beam failure event, a first TRP-specific beam failure event corresponding to the first TRP, or a second TRP-specific beam failure event corresponding to the second TRP; and triggering a beam failure recovery request (BFRQ) based on a priority of the corresponding status of the beam failure event; The method further comprises:

20. A base station, a transceiver configured to enable communication with a user equipment (UE); a processor communicatively coupled to the transceiver, the processor comprising: generating a configuration message instructing the UE to switch to a single TRP mode; generating a beam failure detection (BFD) configuration, the BFD configuration instructing the UE to update a BFD procedure of the UE upon switching to the single TRP mode; Generate a beam failure recovery (BFR) configuration, the BFR configuration instructing the UE to update a BFR procedure of the UE upon switching to the single TRP mode; transmitting, using the transceiver, the configuration message, the BFD configuration, and the BFR configuration to the UE; A base station configured to:

21. 21. The base station of claim 20, wherein the processor is further configured to transmit the configuration message, the BFD configuration and the BFR configuration by transmitting Radio Resource Control (RRC) signaling, a MAC control element (MAC CE), or a downlink control information (DCI).

22. 21. The base station of claim 20, wherein the processor further comprises: receiving, using the transceiver, a plurality of BFR capability reports from the UE; generating a plurality of BFR configurations, the plurality of BFR configurations instructing the UE to trigger a plurality of beam failure recovery requests (BFRQs) upon detecting a plurality of beam failure events; transmitting, using the transceiver, the plurality of BFR configurations to the UE; A base station configured to:

Images