# US 12,192,773 B2 · Communication method and apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,192,773 B2 - Document ID: US12192773B2 - Status: Granted - Kind: B2 - Application number: 17/852,739 - Filed: 2022-06-29 - Published: 2022-10-13 - Granted: 2025-01-07 - Earliest claimed: 2019-12-31 - Assignees: Huawei Technologies Co., Ltd. - Applicants: Huawei Technologies Co., Ltd. - Inventors: Xiangyu Li; Xiao Xiao; Bo Zhang; Jun Wang - Web page: https://patentgrep.com/patent/US12192773B2 ## CPC - H04W 12/50: Secure pairing of devices - H04W 12/03: Protecting confidentiality, e.g. by encryption - H04W 12/106: Packet or message integrity - H04W 76/14: Direct-mode setup - H04W 4/40: for vehicles, e.g. vehicle-to-pedestrians [V2P] - H04W 92/18: between terminal devices - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract A communication method and apparatus are disclosed. According to the communication method, corresponding PDCP entities of a first terminal and a second terminal use consistent input parameters when executing security algorithms, thereby ensuring normal communication on a sidelink (SL) and improving communication reliability. In an example embodiment, a first terminal determines a logical channel identifier (LCID) meeting a preset condition, where a first packet data convergence protocol (PDCP) entity of the first terminal is associated with two or more logical channels (LCHs); the first terminal receives a first data packet from a second terminal; and the first PDCP entity of the first terminal parses the first data packet based on the LCID. ## Claims ### Claim 1 A communication method, comprising: determining, by a first terminal, a first logical channel identifier (LCID) meeting a preset condition, wherein a first packet data convergence protocol (PDCP) entity of the first terminal is associated with two or more logical channels (LCHs); receiving, by the first terminal, a first data packet from a second terminal, wherein security protection is performed on the first packet using a second LCID as an input parameter of a security algorithm of a second PDCP entity of the second terminal; and parsing, by the first PDCP entity of the first terminal, the first data packet using the first LCID, wherein the preset condition met by the first LCID used by the first PDCP entity of the first terminal to parse the first data packet is the same as a preset condition met by the second LCID used by the second terminal to perform the security protection on the first data packet. ### Claim 2 (depends on 1) The method according to claim 1, wherein the preset condition comprises a first preset condition, and a size of the first LCID meets the first preset condition. ### Claim 3 (depends on 2) The method according to claim 2, wherein the determining, by a first terminal, a first logical channel identifier (LCID) meeting a preset condition comprises: determining, by the first terminal according to a preset rule, the first LCID meeting the first preset condition. ### Claim 4 (depends on 2) The method according to claim 2, further comprising: receiving, by the first terminal, first indication information from the second terminal, wherein the first indication information indicates the first terminal to use an LCID meeting the first preset condition as an input parameter of a security algorithm of the first PDCP entity. ### Claim 5 (depends on 4) The method according to claim 4, wherein the determining, by a first terminal, a first logical channel identifier (LCID) meeting a preset condition comprises: determining, by the first terminal based on the first indication information, the first LCID meeting the first preset condition. ### Claim 6 (depends on 5) The method according to claim 5, wherein the first indication information is carried in first sidelink radio bearer (SLRB) configuration information, and the first SLRB configuration information is carried in a PC5-radio resource control (RRC) message. ### Claim 7 (depends on 2) The method according to claim 2, wherein the first LCID meeting the first preset condition is a smallest LCID or a largest LCID in LCIDs corresponding to the two or more LCHs. ### Claim 8 A communication method, comprising: determining, by a second terminal, a second logical channel identifier (LCID) meeting a preset condition, wherein a second packet data convergence protocol (PDCP) entity of the second terminal is associated with two or more logical channels (LCHs); using, by the second terminal, the second LCID as an input parameter of a security algorithm of the second PDCP entity to perform security protection on a first data packet; and sending, by the second terminal, the first data packet on which security protection is performed to a first terminal, wherein the second LCID used by the second terminal to perform security protection on the first data packet is the same as a first LCID used as an input parameter by a first PDCP entity of the first terminal to parse the first data packet, and the first PDCP entity of the first terminal corresponds to the second PDCP entity of the second terminal. ### Claim 9 (depends on 8) The method according to claim 8, wherein the preset condition comprises a first preset condition, and a size of the second LCID meets the first preset condition. ### Claim 10 (depends on 9) The method according to claim 9, wherein the determining, by a second terminal, a second logical channel identifier (LCID) meeting a preset condition comprises: determining, by the second terminal according to a predefined rule, the second LCID meeting the first preset condition. ### Claim 11 (depends on 9) The method according to claim 9, wherein the determining, by a second terminal, a second logical channel identifier (LCID) meeting a preset condition comprises: determining, by the second terminal based on sizes of LCIDs corresponding to the two or more LCHs, an LCID meeting the first preset condition. ### Claim 12 (depends on 9) The method according to claim 9, wherein the second LCID meeting the first preset condition is a smallest LCID or a largest LCID in the LCIDs corresponding to the two or more LCHs. ### Claim 13 A communication apparatus, comprising: at least one processor, and a memory configured to store instructions that, when executed by the at least one processor, cause the apparatus to: determine a first logical channel identifier (LCID) meeting a preset condition, wherein a first packet data convergence protocol (PDCP) entity of a first terminal is associated with two or more logical channels (LCHs); receive a first data packet from a second terminal, wherein security protection is performed on the first data packet using a second LCID as an input parameter of a security algorithm of a second PDCP entity of the second terminal; and parse the first data packet using the first LCID, wherein the preset condition met by the first LCID used by the first terminal to parse the first data packet is the same as a preset condition met by the second LCID used by the second terminal to perform the security protection on the first data packet. ### Claim 14 (depends on 13) The apparatus according to claim 13, wherein the preset condition comprises a first preset condition, and a size of the first LCID meets the first preset condition. ### Claim 15 (depends on 14) The apparatus according to claim 14, wherein the instructions, when executed by the at least one processor, further cause the apparatus to: determine, according to a predefined rule, tbe first LCID meeting the first preset condition. ### Claim 16 (depends on 14) The apparatus according to claim 14, wherein the instructions, when executed by the at least one processor, further cause the apparatus to: receive first indication information from the second terminal, wherein the first indication information indicates the first terminal to use an LCID meeting the first preset condition as an input parameter of a security algorithm of the first PDCP entity. ### Claim 17 (depends on 16) The apparatus according to claim 16, wherein the first LCID meeting the first preset condition is determined based on the first indication information. ### Claim 18 (depends on 17) The apparatus according to claim 17, wherein the first indication information is carried in first sidelink radio bearer (SLRB) configuration information, and the first SLRB configuration information is carried in a PC5-radio resource control (RRC) message. ### Claim 19 (depends on 14) The apparatus according to claim 14, wherein the first LCID meeting the first preset condition is a smallest LCID or a largest LCID in LCIDs corresponding to the two or more LCHs. ### Claim 20 (depends on 1) The communication method according to claim 1, wherein the first LCID used by the first PDCP entity of the first terminal to parse the first data packet is the same as the second LCID used by the second PDCP entity of the second terminal to perform security protection on the first data packet. ### Claim 21 (depends on 4) The communication method according to claim 4, wherein the first indication information includes the second LCID used by the second PDCP entity of the second terminal to perform the security protection on the first data packet.