# US 2019/0356376 A1 · Communication method and communications apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0356376 A1 - Document ID: US20190356376A1 - Status: Published application - Kind: A1 - Application number: 16/528,202 - Filed: 2019-07-31 - Published: 2019-11-21 - Earliest claimed: 2018-01-11 - Applicants: Huawei Technologies Co., Ltd. - Inventors: Chunhua YOU; Le YAN; Hongping ZHANG - Web page: https://patentgrep.com/patent/US20190356376A1 ## CPC - H04B 7/06964: {Re-selection of one or more beams after beam failure} - H04B 7/088: {using beam selection} - H04L 1/0026: {Transmission of channel quality indication} - H04L 5/0051: {of dedicated pilots, i.e. pilots destined for a single user or terminal} - H04W 56/001: {Synchronization between nodes} - H04W 72/046: {the resource being in the space domain, e.g. beams} - H04W 74/02: Hybrid access - H04W 74/0838: using contention-free random access [CFRA] - H04W 76/19: Connection re-establishment - H04W 16/28: using beam steering - H04W 74/04: Scheduled access (hybrid access H04W74/02) - H04W 74/0833: Random access procedures, e.g. with 4-step access - H04B: TRANSMISSION - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract A base station configures, for a terminal, a contention-free random access resource for a beam failure recovery request. After determining that a beam failure has occurred, the terminal performs random access, and retains the contention-free random access resource after the random access succeeds, so that a beam failure recovery latency and signaling overheads can be reduced. ## Claims ### Claim 1 A communication method, comprising: receiving, by an apparatus, configuration information, wherein the configuration information comprises information indicating one or more contention-free random access resources, and wherein the one or more contention-free random access resources comprise a contention-free random access resource for a beam failure recovery request; sending, by the apparatus, a random access request based on the configuration information; and upon random access being completed, retaining, by the apparatus, the contention-free random access resource for a beam failure recovery request. ### Claim 2 (depends on 1) The method according to claim 1, wherein the one or more contention-free random access resources further comprise a contention-free random access resource for cell change. ### Claim 3 (depends on 1) The method according to claim 1, wherein the one or more contention-free random access resources comprises a time-frequency domain resource and/or a code resource. ### Claim 4 (depends on 3) The method according to claim 3, wherein the code resource is a preamble. ### Claim 5 (depends on 1) The method according to claim 1, wherein the configuration information further comprises beam identifiers corresponding to some or all of the contention-free random access resources, and wherein the beam identifiers comprise a synchronization signal block index or a channel state information-reference signal index. ### Claim 6 (depends on 1) The method according to claim 1, wherein the configuration information further comprises an association between identifiers of random access resources and beam identifiers, wherein the random access resources comprise a contention-based random access resource and the contention-free random access resources, and wherein the beam identifiers comprise a synchronization signal block index or a channel state information-reference signal index. ### Claim 7 (depends on 1) The method according to claim 1, wherein the configuration information further comprises information indicating a contention-based random access resource. ### Claim 8 (depends on 1) The method according to claim 1, wherein retaining the contention-free random access resource for a beam failure recovery request comprises: retaining information indicating the contention-free access resource for a beam failure recovery request. ### Claim 9 (depends on 1) The method according to claim 1, further comprising: in response to occurrence of a beam failure, sending a further random access request based on the configuration information; and in response to receiving a response corresponding to the further random access request or receiving a contention resolution message, determining that the random access is successful. ### Claim 10 A communications apparatus, comprising: a transceiver, configured to: receive configuration information, wherein the configuration information comprises information indicating one or more contention-free random access resources, and wherein the one or more contention-free random access resources comprise a contention-free random access resource for a beam failure recovery request; and send a random access request based on the configuration information; and a processor, configured to: upon random access being completed, retain the contention-free random access resource for a beam failure recovery request. ### Claim 11 (depends on 10) The apparatus according to claim 10, wherein the one or more contention-free random access resources further comprise a contention-free random access resource for cell change. ### Claim 12 (depends on 10) The apparatus according to claim 10, wherein the one or more contention-free random access resources comprises a time-frequency domain resource and/or a code resource. ### Claim 13 (depends on 12) The apparatus according to claim 12, wherein the code resource is a preamble. ### Claim 14 (depends on 10) The apparatus according to claim 10, wherein the configuration information further comprises beam identifiers corresponding to some or all of the contention-free random access resources, and wherein the beam identifiers comprise a synchronization signal block index or a channel state information-reference signal index. ### Claim 15 (depends on 10) The apparatus according to claim 10, wherein the configuration information further comprises an association between identifiers of random access resources and beam identifiers, wherein the random access resources comprise a contention-based random access resource and the contention-free random access resources, and wherein the beam identifiers comprise a synchronization signal block index or a channel state information-reference signal index. ### Claim 16 (depends on 10) The apparatus according to claim 10, wherein the configuration information further comprises information indicating a contention-based random access resource. ### Claim 17 (depends on 10) The apparatus according to claim 10, wherein the transceiver is further configured to: in response to occurrence of a beam failure, send a further random access request based on the configuration information; and wherein the processor is further configured to: determine that the random access is successful in response to the transceiver receiving a response corresponding to the random access request or receiving a contention resolution message. ### Claim 18 (depends on 10) The apparatus according to claim 10, wherein retaining the contention-free random access resource for a beam failure recovery request comprises: retaining information indicating the contention-free access resource for a beam failure recovery request. ### Claim 19 A non-transitory computer-readable storage medium having processor-executable instructions stored thereon, wherein the instructions, when executed, facilitate: receiving, by an apparatus, configuration information, wherein the configuration information comprises information indicating one or more contention-free random access resources, and wherein the one or more contention-free random access resources comprise a contention-free random access resource for a beam failure recovery request; sending, by the apparatus, a random access request based on the configuration information; and upon random access being completed, retaining, by the apparatus, the contention-free random access resource for a beam failure recovery request. ### Claim 20 (depends on 19) The medium according to claim 19, wherein the one or more contention-free random access resources comprises a time-frequency domain resource and/or a code resource.