Method and apparatus for beam failure reporting

Abstract

Beam failure reporting is disclosed. This document describes reporting, in a radio access network (140), by a user equipment (110) to a base station (121) of a beam failure, wherein the user equipment (110) receives a first uplink grant (502) and initiates a beam recovery procedure (504). Based on the beam recovery procedure determining that a beam has failed, the user equipment (110) transmits a first medium access control protocol data unit using the first uplink grant, the first medium access control protocol data unit comprising a first MAC control element indicating a first synchronization signal block and a second synchronization signal block, the transmitting effectively causing the base station (121) to determine that the beam failure was detected by the user equipment (110) on the first synchronization signal block based on receiving the first synchronization signal block (506).

Description

[0001] Case Analysis

[0002] This application is a divisional application of Chinese Invention Patent Application No. 201980005832.3, filed on June 15, 2019. Technical Field

[0003] This disclosure generally pertains to beam failure reporting. Background Technology

[0004] The evolution of wireless communication towards fifth-generation (5G) standards and technologies offers higher data rates and greater capacity, while improving reliability and reducing latency, thus enhancing mobile broadband services. 5G technology also enables new service categories for vehicular, fixed wireless broadband, and the Internet of Things (IoT).

[0005] A unified air interface utilizing licensed, unlicensed, and shared licensed radio spectrum across multiple frequency bands is one aspect of enabling 5G systems. The 5G air interface utilizes radio spectrum in bands below 1 GHz (less than 1 GHz), below 6 GHz (less than 6 GHz), and above 6 GHz. Radio spectrum above 6 GHz includes millimeter-wave (mmWave) bands, which provide wide channel bandwidth to support higher data rates for wireless broadband.

[0006] To improve the capacity of 5G radio networks, multiple-input multiple-output (MIMO) antenna systems are used for beamforming signals transmitted between base stations and user terminals. In 5G networks, a large number of MIMO antennas (e.g., hundreds of antennas) are used for signal beamforming, often referred to as massive MIMO, to provide beamforming transmission and reception concentrated in a small area near individual user terminals. Massive MIMO beamforming improves network throughput, energy efficiency, and interference suppression. Massive MIMO systems use channel estimation of the radio frequency (RF) channel characteristics between the base station and user terminals to determine the beamforming coefficients used for transmission and reception.

[0007] In a 5G NR wireless communication system, if the signal strength or quality of the serving downlink transmit beam to a user equipment (e.g., a user equipment or UE) is poor, a lower layer in the network stack (e.g., the physical layer) will send a beam failure instance indication to the Media Access Control (MAC) entity in the UE's network stack. The MAC entity will then perform a beam failure detection / recovery procedure. When a beam failure occurs, the MAC entity will initiate a random access procedure. During the random access procedure, the user equipment will select a downlink transmit beam and choose one of the preambles associated with that downlink transmit beam. After the random access procedure is successfully completed, the serving cell base station (e.g., a gNB) determines that the user equipment has changed its downlink transmit beam.

[0008] The gNB can configure a dedicated preamble or time-frequency resource for the UE to transmit downlink beams. Using these resources, the UE does not compete with other UEs for the preamble. This type of random access procedure is called contention-free random access. Otherwise, the UE would have to perform a contention-based random access procedure, which can take much longer to complete.

[0009] Because the number of preamble and time-frequency resources is limited, in most cases, the UE is not configured with dedicated preamble and time-frequency resources, and therefore uses contention-based random access. Even when the UE is configured with dedicated preamble and time-frequency resources for downlink transmission beams, if the beam's signal strength or signal quality results in poor link quality, the UE still needs to fall back to using a contention-based random access procedure. Summary of the Invention

[0010] This invention is provided to introduce a simplified concept for beam failure reporting. These simplified concepts are further described below in detail. This invention is not intended to identify essential features of the claimed subject matter, nor is it intended for use in determining the scope of the claimed subject matter.

[0011] In various aspects, methods, apparatus, and devices are described for reporting beam faults by a user equipment (UE) in a wireless communication network, wherein the UE receives a first uplink grant and initiates a beam recovery procedure. Based on the beam recovery procedure, it is determined that a beam has failed, and the UE uses the first uplink grant to transmit a first Media Access Control (MAC) data unit (MAC) including a first MAC control element indicating a first synchronization block and a second synchronization block. The transmission effectively enables the base station to determine, based on receiving the first synchronization block, that the beam fault was detected by the UE on the first synchronization block.

[0012] In other aspects, methods, apparatus, and devices for managing beam fault reports from user equipment by a base station in a wireless communication network are described, wherein the base station receives a first Media Access Control (MAC) data unit from the user equipment, the first MAC data unit including a first MAC control element indicating a first synchronization block and a second synchronization block. Based on receiving the first synchronization block, the base station determines that the user equipment has detected a beam fault on the first synchronization block, and the base station selects a first downlink transmission beam with a lighter traffic load from among the beams associated with the synchronization block indicated in the first MAC control element, the first downlink transmission beam being associated with the first synchronization block. Attached Figure Description

[0013] Refer to the following figures to describe various aspects of beam failure reporting. In all figures, the same numbers are used to refer to similar features and components:

[0014] Figure 1 The diagram illustrates an example wireless network environment capable of implementing various aspects of beam fault reporting.

[0015] Figure 2 The diagram shows an example device capable of implementing various aspects of beam fault reporting.

[0016] Figure 3 The diagram shows an example block diagram of a network stack model that can be used to implement various aspects of beam fault reporting technology.

[0017] Figure 4 The diagram illustrates the air interface resources that extend between user equipment and base stations and can be used to implement various aspects of beam fault reporting technology.

[0018] Figure 5 The illustration shows an example method for beam failure reporting according to various aspects of the technology described herein. Detailed Implementation

[0019] In a 5G NR wireless communication system, if the signal strength or signal quality of the downlink transmit beam to a user equipment (e.g., a user equipment or UE) is poor, a lower layer in the network stack (e.g., the physical layer) will send a beam failure instance indication to the Media Access Control (MAC) entity in the UE's network stack. The MAC entity will perform a beam failure detection / recovery procedure. When a beam failure occurs, the MAC entity will initiate a random access procedure. During the random access procedure, the user equipment will select a downlink transmit beam and choose one of the preambles associated with that downlink transmit beam. After the random access procedure is successfully completed, the serving cell base station (e.g., a gNB) determines that the user equipment has changed its downlink transmit beam.

[0020] Base stations can configure dedicated preamble or time-frequency resources for user equipment (UEs) to transmit downlink beams. Using these resources, UEs do not compete with other UEs for the preamble. This type of random access procedure is called contention-free random access. Otherwise, UEs would have to perform a contention-based random access procedure, which can take much longer to complete.

[0021] Because the number of preamble and time-frequency resources is limited, user equipment (UE) is not configured with dedicated preamble and time-frequency resources in most cases, and therefore uses contention-based random access. Even when UE is configured with dedicated preamble and time-frequency resources for downlink transmission beams, if the beam signal strength or signal quality results in poor link quality, the UE still needs to fall back to using a contention-based random access procedure.

[0022] In this document, a method for reporting beam faults is described that reduces the amount of time required to perform the beam recovery process. The user equipment (UE) uses a configured permission to send beam fault information to the base station. When a beam fault occurs, the UE may be unable to receive an uplink permission from the base station, and therefore the UE may be unable to send beam fault information to the base station. However, if the UE has received a configured permission, it can still use that permission to send beam fault information to the network.

[0023] In the uplink, the base station can dynamically allocate resources to the UE via the Cell Radio Network Temporary Identifier (C-RNTI) on the Physical Downlink Control Channel (PDCCH). The UE monitors the PDCCH to find possible permission for uplink transmission when its downlink reception is enabled, which is an activity governed by Discontinuous Reception (DRX) when configured. When Cell Allocation (CA) is configured, the same C-RNTI applies to all serving cells.

[0024] Furthermore, by utilizing the configured permissions, the base station can allocate uplink resources to the UE for initial Hybrid Automatic Repeat Request (HARQ) transmissions. Two types of configured uplink permissions are defined:

[0025] Type 1, where Radio Resource Control (RRC) directly provides configured uplink licenses (including periods), and

[0026] Type 2, where RRC defines the period of the configured uplink license, and PDCCH addressed to the configured Scheduled Radio Network Temporary Identifier (CS-RNTI) can signal and activate the configured uplink license, or deactivate the configured uplink license (e.g., PDCCH addressed to CS-RNTI indicates that the uplink license can be implicitly reused according to the period defined by RRC until the uplink license is deactivated).

[0027] When the configured uplink license is active, if the user equipment (UE) cannot find its C-RNTI or CS-RNTI on the PDCCH, the UE can perform uplink transmission according to the configured uplink license. Otherwise, if the UE finds its C-RNTI or CS-RNTI on the PDCCH, the PDCCH allocates an override uplink license. Retransmissions other than duplicates are explicitly allocated via the PDCCH.

[0028] When CA is configured, up to one configured uplink license can be signaled per serving cell. When Broadcast Control Channel (BCCH) allocation (BA) is configured, up to one configured uplink license can be signaled per bandwidth portion (BWP). Only one configured uplink license can be active at a time per serving cell. A serving cell's configured uplink license can have either Type 1 or Type 2 as previously described. For Type 2, activation and deactivation of the configured uplink license are independent within the serving cell. When Supplementary Uplink (SUL) is configured, a configured uplink license can only be signaled for one of the two uplinks of the cell.

[0029] Example Environment

[0030] Figure 1The illustration includes an example environment 100 of user equipment 110 (UE 110), which is capable of communicating with base stations 120 (illustrated as base stations 121 and 122) via wireless communication link 130 (wireless link 130) illustrated as wireless links 131 and 132. For simplicity, UE 110 is implemented as a smartphone, but can be implemented as any suitable computing or electronic device such as: mobile communication device, modem, cellular phone, gaming device, navigation device, media device, laptop computer, desktop computer, tablet computer, smart home appliance, vehicle-based communication system, or Internet of Things (IoT) device, such as sensor or actuator. Base station 120 (e.g., Evolved Universal Terrestrial Radio Access Network Node B, E-UTRAN Node B, Evolved Node B, eNodeB, eNB, Next Generation Node B, gNode B, gNB, etc.) can be implemented in macro cells, micro cells, small cells, pico cells, etc., or any combination thereof.

[0031] Base station 120 uses radio links 131 and 132 to communicate with user equipment 110, and these radio links 131 and 132 can be implemented as any suitable type of radio link. Radio links 131 and 132 include control and data communications, such as downlinks transmitting data and control information from base station 120 to user equipment 110, uplinks transmitting other data and control information from user equipment 110 to base station 120, or both. Radio link 130 may include one or more radio links (e.g., radio links) or bearers implemented using any suitable communication protocol or standard or combination of communication protocols or standards, such as 3GPP LTE, 5G NR, etc. Multiple radio links 130 can be aggregated in carrier aggregation to provide higher data rates for UE 110. Multiple radio links 130 from multiple base stations 120 can be configured for Coordinated Multipoint (CoMP) communication with UE 110.

[0032] Base station 120 is collectively a radio access network 140 (e.g., RAN, Evolved Universal Terrestrial Radio Access Network, E-UTRAN, 5G NR RAN, or NR RAN). Base stations 121 and 122 in RAN 140 are connected to core network 150. Base stations 121 and 122, respectively, connect to core network 150 at 102 via an NG2 interface for control plane signaling and an NG3 interface for user plane data communication when connected to the 5G core network, or via an S1 interface for control plane signaling and user plane data communication when connected to the evolved packet core (EPC) network. At 102, base stations 121 and 122 can communicate via an Xn interface using the Xn Application Protocol (XnAP) or via an X2 interface using the X2 Application Protocol (X2AP) to exchange user plane and control plane data. User equipment 110 can connect to a public network such as the Internet 160 via core network 150 to interact with remote service 170.

[0033] Figure 2 Figure 200 illustrates an example apparatus diagram of user equipment 110 and base station 120. User equipment 110 and base station 120 may include, for clarity, [from...] Figure 2 Additional functions and interfaces are omitted. User equipment 110 includes an antenna 202, a radio frequency front-end 204 (RF front-end 204), an LTE transceiver 206, and a 5G NR transceiver 208 for communication with base station 120 in RAN 140. The RF front-end 204 of user equipment 110 can couple or connect the LTE transceiver 206 and the 5G NR transceiver 208 to the antenna 202 to facilitate various types of wireless communication. The antenna 202 of user equipment 110 may include an array of multiple antennas configured similarly or differently from each other. The antenna 202 and the RF front-end 204 can be tuned to and / or tunable to one or more frequency bands defined by the 3GPP LTE and 5G NR communication standards and implemented by the LTE transceiver 206 and / or the 5G NR transceiver 208. Additionally, antenna 202, RF front-end 204, LTE transceiver 206, and / or 5G NR transceiver 208 can be configured to support beamforming for transmitting and receiving communications with base station 120. By way of example and not limitation, antenna 202 and RF front-end 204 can be implemented for operation in sub-gigahertz, sub-6 GHz, and / or higher frequency bands as defined by 3GPP LTE and 5G NR communication standards.

[0034] User equipment 110 also includes a processor 210 and a computer-readable storage medium 212 (CRM 212). The processor 210 may be a single-core or multi-core processor made of various materials including silicon, polysilicon, high-k dielectrics, copper, etc. The computer-readable storage medium described herein excludes propagating signals. CRM 212 may include any suitable memory or storage device, such as random access memory (RAM), static RAM (SRAM), dynamic RAM (DRAM), non-volatile RAM (NVRAM), read-only memory (ROM), or flash memory that can be used to store device data 214 of user equipment 110. Device data 214 includes user data, multimedia data, beamforming codebooks, applications, and / or operating systems of user equipment 110, which can be executed by processor 210 to enable user plane communications, control plane signaling, and user interaction with user equipment 110.

[0035] In some implementations, CRM 212 may also include beamforming manager 216. Alternatively or additionally, beamforming manager 216 may be implemented wholly or partially as hardware logic or circuitry integrated or separate from other components of user equipment 110. Beamforming manager 216 is capable of communicating with antenna 202, RF front-end 204, LTE transceiver 206, and / or 5G NR transceiver 208 to implement the techniques used for cross-carrier hybrid automatic repeat request described herein.

[0036] Figure 2 The device diagram of base station 120 shown includes a single network node (e.g., gNode B). The functionality of base station 120 can be distributed across multiple network nodes or devices and can be distributed in any manner suitable for performing the functions described herein. Base station 120 includes an antenna 252, a radio frequency front-end 254 (RF front-end 254), one or more LTE transceivers 256 and / or one or more 5G NR transceivers 258 for communicating with UE 110. The RF front-end 254 of base station 120 is capable of coupling or connecting the LTE transceivers 256 and 5G NR transceivers 258 to the antenna 252 to facilitate various types of wireless communication. The antenna 252 of base station 120 may include an array of multiple antennas configured similarly or differently from each other. The antenna 252 and RF front-end 254 can be tuned to and / or are tunable to one or more frequency bands defined by the 3GPP LTE and 5G NR communication standards and implemented by the LTE transceivers 256 and / or 5G NR transceivers 258. Additionally, antenna 252, RF front end 254, LTE transceiver 256 and / or 5G NR transceiver 258 can be configured to support beamforming such as massive MIMO for transmission and reception of communications with UE 110.

[0037] Base station 120 also includes processor 260 and computer-readable storage medium 262 (CRM 262). Processor 260 may be a single-core or multi-core processor comprising various materials such as silicon, polysilicon, high-k dielectric, copper, etc. CRM 262 may include any suitable memory or storage device, such as random access memory (RAM), static RAM (SRAM), dynamic RAM (DRAM), non-volatile RAM (NVRAM), read-only memory (ROM), or flash memory that can be used to store device data 264 of base station 120. Device data 264 includes network scheduling data, radio resource management data, beamforming codebook, applications and / or operating systems of base station 120, which can be executed by processor 260 to enable communication with user equipment 110.

[0038] CRM 262 also includes a base station manager 266. Alternatively or additionally, the base station manager 266 may be implemented wholly or partially as hardware logic or circuitry integrated or separate from other components of the base station 120. In at least some aspects, the base station manager 266 configures the LTE transceiver 256 and the 5G NR transceiver 258 for communication with the user equipment 110, as well as with a core network such as the core network 150.

[0039] Base station 120 includes an inter-base station interface 268, such as an Xn interface and / or an X2 interface. Base station manager 266 configures the inter-base station interface 268 to exchange user plane and control plane data between other base stations 120 to manage communication between base station 120 and user equipment 110. Base station 120 includes a core network interface 270, which base station manager 266 configures to exchange user plane and control plane data with core network functions and / or entities.

[0040] User plane and control plane signaling

[0041] Figure 3 The diagram illustrates an example block diagram 300 of a wireless network stack model 300 (stack 300). Stack 300 represents a communication system for example environment 100, in which various aspects of beam fault reporting are implemented. Stack 300 includes a user plane 302 and a control plane 304. Upper layers of user plane 302 and control plane 304 share common lower layers in stack 300. Wireless devices such as UE 110 or base station 120 implement each layer as an entity for communicating with another device using a protocol defined for that layer. For example, UE 110 uses a Packet Data Convergence Protocol (PDCP) entity to communicate with a peer PDCP entity in base station 120 that uses PDCP.

[0042] The shared lower layers include the Physical (PHY) layer 306, the Media Access Control (MAC) layer 308, the Radio Link Control (RLC) layer 310, and the PDCP layer 312. The PHY layer 306 provides hardware specifications for devices communicating with each other. Therefore, the PHY layer 306 establishes how devices connect to each other and helps manage how communication resources are shared among devices.

[0043] MAC layer 308 specifies how data is transmitted between devices. Typically, MAC layer 308 provides the method for encoding and decoding the data packets being transmitted into bits that are part of the transport protocol.

[0044] RLC layer 310 provides data transmission services to higher layers in stack 300. Typically, RLC layer 310 provides error correction, packet segmentation and reassembly, and management of data transmission in various modes such as acknowledge, no acknowledge, or transparent modes.

[0045] The PDCP layer 312 provides data transmission services to higher layers in the stack 300. Typically, the PDCP layer 312 provides data transmission, header compression, encryption, and integrity protection for user plane 302 and control plane 304.

[0046] Above the PDCP layer 312, the stack is split into a user plane 302 and a control plane 304. The user plane 302 includes an optional Service Data Adaptation Protocol (SDAP) layer 314, an Internet Protocol (IP) layer 316, a Transmission Control Protocol / User Datagram Protocol (TCP / UDP) layer 318, and an application layer 320, which uses radio link 131 to transmit data. The optional SDAP layer 314 is present in 5G NR networks. The SDAP layer 314 maps Quality of Service (QoS) flows for each data radio bearer and marks QoS flow identifiers in uplink and downlink data packets for each packet data session. The IP layer 316 specifies how data from the application layer 320 is delivered to the destination node. The TCP / UDP layer 318 is used to verify that data packets intended for delivery to the destination node have arrived at the destination node using either TCP or UDP, which is used for data transmission by the application layer 320. In some implementations, the user plane 302 may also include a data service layer (not shown) that provides data transmission services to transmit application data, such as IP packets including web browsing content, video content, image content, audio content, or social media content.

[0047] Control plane 304 includes a Radio Resource Control (RRC) layer 324 and a Non-Access Stratum (NAS) layer 326. RRC layer 324 establishes and releases connections and radio bearers, broadcasts system information, or performs power control. RRC layer 324 also controls the resource control state of UE 110 and causes UE 110 to perform operations according to that resource control state. Example resource control states include connected states (e.g., RRC connected state) or disconnected states, such as inactive states (e.g., RRC inactive state) or idle states (e.g., RRC idle state). Generally, if UE 110 is in a connected state, the connection with base station 120 is active. In an inactive state, the connection with base station 120 is suspended. If UE 110 is in an idle state, the connection with base station 120 is released. Typically, RRC layer 324 supports 3GPP access but not non-3GPP access (e.g., WLAN communication).

[0048] NAS layer 326 provides support for mobility management (e.g., using fifth-generation mobility management (5GMM) layer 328) and packet data bearer context (e.g., using fifth-generation session management (5GSM) layer 330) between UE 110 and entities or functions in the core network, such as the Access and Mobility Management Function (AMF) of the core network 150. NAS layer 326 supports both 3GPP access and non-3GPP access.

[0049] In UE 110, each layer of the user plane 302 and control plane 304 of stack 300 interacts with the corresponding peer layer or entity, core network entity or function and / or remote service in base station 120 to support user applications and control the operation of UE 110 in RAN 140.

[0050] Figure 4 The illustration shows air interface resources that extend between the user equipment and the base station and can be used to implement various aspects of beam fault reporting. Air interface resource 402 can be divided into resource elements 404, each occupying a certain intersection of spectrum and elapsed time. A portion of air interface resource 402 is schematically illustrated in a grid or matrix having multiple resource blocks 410 including resource blocks 411, 412, 413, and 414. An example of resource element 404 thus includes at least one resource block 410. As shown, time is depicted along the horizontal dimension on the x-axis, and frequency is depicted along the vertical dimension on the y-axis. As defined by a given communication protocol or standard, air interface resource 402 can span any suitable specified frequency range and / or can be divided into intervals of any specified duration. Time increments can correspond to, for example, milliseconds (mSec). Frequency increments can correspond to, for example, megahertz (MHz).

[0051] In typical example operation, base station 120 allocates portions of air interface resources 402 (e.g., resource elements 404) for uplink and downlink communications. Each resource block 410 of network access resources can be allocated to support corresponding wireless communication links 130 for multiple user equipments 110. In the lower left corner of the grid, resource block 411 can span a specified frequency range 406 and include multiple subcarriers or frequency subbands, as defined by a given communication protocol. Resource block 411 can include any suitable number of subcarriers (e.g., 12), each corresponding to a corresponding portion (e.g., 15 kHz) of the specified frequency range 406 (e.g., 180 kHz). Resource block 411 can also span a specified time interval 408 or time slot (e.g., lasting approximately half a millisecond or 7 orthogonal frequency division multiplexing (OFDM) symbols), as defined by a given communication protocol. Time interval 408 includes sub-segments that can each correspond to symbols such as OFDM symbols. Figure 4 As shown, each resource block 410 may include a plurality of resource elements 420 (REs), which correspond to, or are defined by, subcarriers of frequency range 406 and sub-intervals (or symbols) of time interval 408. Alternatively, a given resource element 420 may span more than one frequency subcarrier or symbol. Therefore, resource unit 404 may include at least one resource block 410, at least one resource element 420, etc.

[0052] In the example implementation, multiple user equipment 110s (one shown) are communicating with base station 120 via access provided by a portion of air interface resource 402. Base station manager 266 (in...) Figure 4 (Not shown) The appropriate type or amount of information (e.g., data or control information) to be transmitted (e.g., sent) by user equipment 110 can be determined. For example, base station manager 266 is able to determine that each user equipment 110 will send a different appropriate amount of information. Base station manager 266 then allocates one or more resource blocks 410 to each user equipment 110 based on the determined amount of information.

[0053] Alternatively, or as an alternative to block-level resource licensing, base station manager 266 can allocate resource units at the element level. Therefore, base station manager 266 can allocate one or more resource elements 420 or individual subcarriers to different user equipment 110. By doing so, a resource block 410 can be allocated to facilitate network access for multiple user equipment 110. Additionally, base station manager 266 can allocate one or more subcarriers or resource elements 420 of resource block 410 to a single user equipment 110 at various granularities, or divide it across multiple user equipment 110, thereby achieving higher network utilization or improved spectral efficiency.

[0054] The base station manager 266 can therefore allocate air interface resources 402 according to resource units 404, resource blocks 410, frequency carriers, time intervals, resource elements 420, frequency subcarriers, time sub-intervals, symbols, spreading codes, or some combination thereof. Based on the corresponding allocation of resource units 404, the resource manager can send a corresponding message to each user equipment 110 indicating the corresponding allocation of resource units 404. Each message can enable the corresponding user equipment 110 to queue information or configure the LTE transceiver 206, 5G NR transceiver 208, or both to communicate via the allocated air interface resources 402 through resource units 404.

[0055] Beam failure report

[0056] In one aspect, if user equipment 110 has initiated a beam recovery process but has not yet completed it, user equipment 110 sends a first MAC protocol data unit (PDU) including a first MAC control element (CE) to base station 121 on the first uplink clearance. In another aspect, the first MAC CE is associated with a first logical channel identifier (LCID), and the first LCID is used to identify the first MAC CE.

[0057] In another aspect, the first MAC CE is associated with the first MAC sub-header in the first MAC PDU. The first MAC sub-header includes an LCID field, which includes the value of a first LCID. Base station 121 parses the first MAC PDU. If base station 121 detects a MAC sub-header in which the LCID field includes the first LCID, then base station 121 determines that this MAC sub-header is the first MAC sub-header, and base station 121 expects the first MAC CE to follow the first MAC sub-header.

[0058] In another aspect, the first MAC CE includes a first field indicating one or more Synchronization Signal Blocks (SSBs). Each SSB is associated with a downlink transmit beam. The first field is a bitmap, where each bit of the bitmap is associated with an SSB. If the value of a bit is set to a first value, the user equipment 110 selects the SSB associated with that bit. If the value of a bit is set to a second value, the user equipment 110 does not select the SSB associated with that bit.

[0059] In another aspect, the first field consists of one or more SSB ID subfields. If user equipment 110 selects an SSB, the SSB ID of that SSB is provided in one of the SSB ID subfields. For example, if the Reference Signal Received Quality (RSRP) (e.g., SS-RSRP) of the Synchronization Symbol (SS) block is higher than a threshold (e.g., as defined in 3GPP TS 38.321 MAC). rsrp-ThresholdSSB User equipment 110 selects the SSB. In another example, if the Channel State Information (CSI) Reference Signal (RS) of the SSB is higher than a threshold (e.g., defined in 3GPP TS 38.321 MAC), the SSB is selected. rsrp- ThresholdCSI-RS The user equipment selects this SSB.

[0060] Of all the aspects, the first uplink permission is a type 1 configured permission. Base station 121 sends the configuration of the type 1 configured permission to user equipment 110. The configuration includes the uplink permission. Once user equipment 110 completes the configuration, user equipment 110 can use the configured permission to send uplink data.

[0061] In another scenario, the first uplink permission is a type 2 configured permission. Base station 121 transmits the configuration of the type 2 configured permission. Then, base station 121 transmits downlink control information (e.g., DCI) to user equipment 110 on the physical downlink control channel (PDCCH) addressing the configured Scheduled Radio Network Temporary Identifier (CS-RNTI). User equipment 110 can then use the configured permission to transmit uplink data, given the CS-RNTI in the configuration of the type 2 configured permission. Alternatively, the first uplink permission can also be a permission given in the DCI on the PDCCH addressing the CS-RNTI.

[0062] In another aspect, based on the received first MAC PDU, base station 121 determines that user equipment 110 has detected a beam fault and that user equipment 110 is requesting to change the downlink transmit beam to one of the beams associated with the SSB indicated in the first MAC CE. Base station 121 randomly selects or selects a first downlink transmit beam with a lighter traffic load from the beams associated with the SSB indicated in the first MAC CE. The first downlink transmit beam is associated with the first SSB.

[0063] In another aspect, the second MAC PDU includes a second MAC CE, which includes a bitmap or SSBID field. In this bitmap, base station 121 sets the bits associated with the first SSB to a first value. Alternatively, base station 121 provides the SSB ID of the first SSB in the SSB ID field.

[0064] In another aspect, the second MAC CE is associated with a second LCID. The LCID is used to identify the second MAC CE. The second MAC CE is associated with a second MAC subheading. The second MAC subheading includes an LCID field, which includes the value of the second LCID. In this way, when user equipment 110 detects a MAC subheading with an LCID field including the second LCID, user equipment 110 determines that the MAC subheading is the second MAC subheading, and user equipment 110 expects the second MAC CE to follow the second MAC subheading.

[0065] In another aspect, base station 121 transmits the second MAC PDU on the first downlink transmit beam. Alternatively, base station 121 transmits the second MAC PDU on each downlink transmit beam associated with the SSB indicated in the first MAC CE.

[0066] If user equipment 110 receives a second MAC CE, it considers the beam recovery process complete. However, if the random access procedure triggered by beam recovery is still running, user equipment 110 either aborts the random access procedure or begins beam fault detection for the first SSB.

[0067] Example Method

[0068] Refer to one or more aspects of the beam failure report Figure 5 Example method 500 is described. Typically, any of the components, modules, methods, and operations described herein can be implemented using software, firmware, hardware (e.g., fixed logic circuitry), manual processing, or any combination thereof. Some operations of the example methods can be described in the general context of executable instructions stored on computer-readable storage memory local and / or remote on a computer processing system, and implementations can include software applications, programs, functions, etc. Alternatively or additionally, any functionality described herein can be performed at least in part by one or more hardware logic components, such as, but not limited to, field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), system-on-a-chip (SoCs), complex programmable logic devices (CPLDs), etc.

[0069] Figure 5The illustration shows an example method 500 for beam fault reporting. The order of the described method boxes is not intended to be interpreted as a limitation, and any number of described method boxes can be combined or skipped in any order to implement the method or an alternative method.

[0070] At box 502, the user equipment (e.g., user equipment 110) receives the first uplink grant. At box 504, the user equipment initiates a beam recovery procedure.

[0071] At block 506, based on the beam recovery process determining that a beam has failed, the user equipment uses a first uplink grant to transmit a first media access control protocol data unit (MAC data unit), the first MAC data unit including a first MAC control element indicating a first synchronization block and a second synchronization block. This transmission enables the base station (e.g., base station 121) to determine, based on the receipt of the first synchronization block, that the beam failure was detected by the user equipment on the first synchronization block.

[0072] Some examples are described below:

[0073] Example 1: A method (500) for a user equipment (110) to report a beam fault to a base station (120) in a wireless communication network, the method comprising:

[0074] The user equipment receives (502) a first uplink permission;

[0075] The user equipment initiates a beam recovery process (504); and

[0076] Based on the beam recovery process, it is determined that the beam has failed. The first uplink permission is used to send (506) a first media access control protocol data unit, the first media access control protocol data unit including a first MAC control element indicating a first synchronization block and a second synchronization block. The transmission effectively enables the base station to determine, based on the receipt of the first synchronization block, that the beam failure was detected by the user equipment on the first synchronization block.

[0077] Example 2: According to the method of Example 1, the first MAC control element is associated with a first logical channel identifier, and the first logical channel identifier can be used to identify the first MAC control element.

[0078] Example 3: According to the method described in Example 2, wherein the first MAC control element is associated with a first MAC subheader in the first Media Access Control Protocol (MAC) data unit, wherein the first MAC subheader has a logical channel identifier field with a value of the first logical channel identifier, and wherein the first MAC subheader precedes the first MAC control element in the MAC data unit.

[0079] Example 4: According to the method of any of the preceding examples, wherein the first MAC control element includes a first field indicating one or more synchronization signal blocks, each synchronization signal block being associated with a downlink transmit beam.

[0080] Example 5: The method according to Example 4, wherein the first field is a bitmap, wherein each bit of the bitmap is associated with a synchronization signal block, the method further comprising:

[0081] If the value of the bit is set to a first value, the user equipment selects the synchronization signal block associated with the bit; or

[0082] If the value of the bit is set to the second value, the synchronization signal block associated with the bit is not selected.

[0083] Example 6: The method according to Example 4 or Example 5, wherein the first field consists of one or more synchronization signal block identifier subfields, wherein if the user equipment selects a synchronization signal block, the synchronization signal block identifier of the synchronization signal block is provided in one of the synchronization signal block identifier subfields.

[0084] Example 7: The method according to Example 5 or Example 6 further includes:

[0085] If the reference signal reception quality of the synchronization signal block is higher than a threshold, then the user equipment selects the synchronization signal block.

[0086] Example 8: According to the method described in Example 3, the method further includes:

[0087] If the channel state information reference signal of the synchronization signal block is higher than the threshold, the user equipment selects the synchronization signal block.

[0088] Example 9: The method according to any of the foregoing examples, wherein the first uplink license is a type 1 configured license, the method further includes:

[0089] The user equipment receives the type 1 configuration of the license, the configuration including an uplink license; and

[0090] Use the above configuration to send uplink data.

[0091] Example 10: The method according to any one of Examples 1 to 8, wherein the first uplink license is a type 2 configured license, the method further includes:

[0092] The user equipment receives the license configuration configured for type 2.

[0093] Receive downlink control information on the physical downlink control channel addressed to the configured scheduling radio network temporary identifier of the user equipment; and

[0094] The permission configured to send uplink data is used, wherein the configuration of the permission for the type 2 configuration includes the temporary identifier of the scheduled radio network.

[0095] Example 11: The method according to any of the preceding examples, wherein the first uplink permission is a permission given in downlink control information on a physical downlink control channel addressed to a configured scheduling radio network temporary identifier.

[0096] Example 12: The method according to any of the foregoing examples further includes:

[0097] Based on the receipt of the second MAC control element, the user equipment determines that the beam recovery process is complete.

[0098] Example 13: The method according to Example 12, wherein the random access procedure triggered by the beam recovery process is still running, the method further includes:

[0099] The random access procedure is terminated by the user equipment.

[0100] Example 14: A user equipment (110) comprising:

[0101] Wireless transceiver (202);

[0102] Processor (210); and

[0103] The memory (212) includes instructions executable by the processor to perform any one of the methods described according to Examples 1 to 13.

[0104] Example 15: A method for managing beam fault reports from user equipment (110) by a base station (120) in a wireless communication network, the method comprising:

[0105] The base station receives a first media access control protocol data unit, the first media access control protocol data unit including a first MAC control element indicating a first synchronization signal block and a second synchronization signal block;

[0106] Based on the receipt of the first synchronization signal block, it is determined that the user equipment detected a beam fault on the first synchronization signal block; and

[0107] A first downlink transmit beam with a lighter traffic load is selected from the beams associated with the synchronization signal block indicated in the first MAC control element, the first downlink transmit beam being associated with the first synchronization signal block.

[0108] Example 16: According to the method described in Example 15, the base station randomly selects the first downlink transmission beam.

[0109] Example 17: The method according to Example 15 or Example 16, wherein the second Media Access Control Protocol data unit includes a second MAC control element comprising a bitmap, the method further comprising:

[0110] In the bitmap, the base station sets the bit associated with the first synchronization signal block to a first value.

[0111] Example 18: The method according to any one of Examples 15 to 17, wherein the second Media Access Control Protocol data unit includes a second MAC control element comprising a synchronization signal block identifier field, the method further comprising:

[0112] The base station provides the synchronization signal block identifier of the first synchronization signal block in the synchronization signal block identifier field.

[0113] Example 19: The method according to Examples 17 to 18, wherein the second MAC control element is associated with a second logical channel identifier, the logical channel identifier being capable of identifying the second MAC control element.

[0114] Example 20: According to the method of Example 19, wherein the second MAC control element is associated with a second MAC subheader in the second media access control protocol data unit, wherein the second MAC subheader has a logical channel identifier field with a value of the second logical channel identifier, and wherein the second MAC subheader precedes the second MAC control element in the second media access control protocol data unit.

[0115] Example 21: The method according to any one of Examples 17 to 20 further includes:

[0116] The base station transmits the second Media Access Control Protocol (MAC) data unit on the first downlink transmission beam.

[0117] Example 22: The method according to any one of Examples 17 to 21 further includes:

[0118] The base station transmits the second Media Access Control Protocol (MAC) data unit on each downlink transmit beam associated with the synchronization signal block indicated in the first MAC control element.

[0119] Example 23: A base station (120) comprising:

[0120] Wireless transceiver (252);

[0121] Processor (260); and

[0122] The memory (262) includes instructions executable by the processor to perform any of the methods described according to Examples 15 to 22.

[0123] Although aspects of beam failure reporting have been described in feature- and / or method-specific language, the subject matter of the appended claims is not necessarily limited to the specific features or methods described. Rather, specific features and methods are disclosed as exemplary implementations of beam failure reporting, and other equivalent features and methods are intended to be within the scope of the appended claims. Furthermore, various different aspects have been described, and it should be understood that each described aspect can be implemented independently or in conjunction with one or more other described aspects.

Claims

1. A method for a user equipment to report a beam fault to a base station in a wireless communication network, the method comprising: The user equipment receives the first uplink permission; The beam recovery process is initiated by the user equipment. as well as Based on the beam recovery process, it is determined that the beam has failed. The first uplink permission is used to send a first Media Access Control (MAC) data unit to the base station. The first MAC data unit includes a first MAC control element, which indicates one or more Synchronization Signal Blocks (SSBs) to indicate that the user equipment is requesting to change from the failed beam to a downlink transmission beam associated with one of the one or more SSBs indicated in the MAC control element.

2. The method according to claim 1, wherein, The first MAC control element is associated with a first logical channel identifier, wherein the first logical channel identifier can be used to identify the first MAC control element.

3. The method according to claim 2, wherein, The first MAC control element is associated with a first MAC subheader in the first Media Access Control Protocol (MAC) data unit, wherein the first MAC subheader has a logical channel identifier field with a value of the first logical channel identifier, and wherein the first MAC subheader precedes the first MAC control element in the MAC data unit.

4. The method according to claim 1, wherein, The first MAC control element includes a first field indicating one or more synchronization signal blocks, each of which is associated with a downlink transmit beam.

5. The method according to claim 4, wherein, The first field is a bitmap, wherein each bit in the bitmap is associated with a synchronization signal block, and the method further includes: If the value of the bit is set to a first value, the user equipment selects the synchronization signal block associated with the bit; or If the value of the bit is set to the second value, the synchronization signal block associated with the bit is not selected.

6. The method according to claim 4, wherein, The first field consists of one or more synchronization signal block identifier subfields, wherein if the user equipment selects a synchronization signal block, the synchronization signal block identifier of the synchronization signal block is provided in one of the synchronization signal block identifier subfields.

7. The method according to claim 5, further comprising: If the reference signal reception quality in the synchronization signal block is higher than a threshold, then the user equipment selects the synchronization signal block.

8. The method according to claim 3, further comprising: If the channel state information reference signal of the synchronization signal block is higher than the threshold, the user equipment selects the synchronization signal block.

9. The method according to claim 1, wherein, The first uplink license is a type 1 configured license, and the method further includes: The user equipment receives the type 1 configuration of the license, the configuration including an uplink license; and Use the above configuration to send uplink data.

10. The method according to claim 1, wherein, The first uplink license is a type 2 configured license, and the method further includes: The user equipment receives the license configuration configured for type 2. Receive downlink control information on the physical downlink control channel addressed to the configured scheduling radio network temporary identifier of the user equipment; and Use the configured license to send uplink data, wherein the configuration of the type 2 configured license includes the configured scheduling radio network temporary identifier.

11. The method according to claim 1, wherein, The first uplink permission is a permission given in the downlink control information on the physical downlink control channel addressed to the configured scheduling radio network temporary identifier.

12. The method of claim 1, further comprising: Based on the receipt of the second MAC control element, the user equipment determines that the beam recovery process is complete.

13. The method according to claim 12, wherein, The method further includes the following: Since the random access procedure triggered by the beam recovery process is still running, the method also includes: The random access procedure is terminated by the user equipment.

14. A user equipment, comprising: Wireless transceiver; processor; and The memory includes instructions that can be executed by the processor for: Receive the first uplink permission; Initiating the beam recovery process; and Based on the beam recovery process, it is determined that the beam has failed. The first uplink permission is used to send a first Media Access Control (MAC) data unit to the base station. The first MAC data unit includes a first MAC control element, which indicates one or more Synchronization Signal Blocks (SSBs) to indicate that the user equipment is requesting to change from the failed beam to a downlink transmission beam associated with one of the one or more SSBs indicated in the MAC control element.

15. A base station, comprising: Wireless transceiver; processor; and The memory includes instructions that can be executed by the processor for: Receive a first Media Access Control Protocol (MAC) data unit that includes a first MAC control element indicating one or more synchronization signal blocks; Based on the received first MAC control element, it is determined that the user equipment has detected a beam fault; as well as Select a first downlink transmit beam associated with one or more synchronization signal blocks indicated in the first MAC control element.

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