# US 11,452,141 B2 · Techniques for formatting random access messages in wireless communications > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,452,141 B2 - Document ID: US11452141B2 - Status: Granted - Kind: B2 - Application number: 16/785,345 - Filed: 2020-02-07 - Published: 2020-09-10 - Granted: 2022-09-20 - Earliest claimed: 2019-03-04 - Assignees: QUALCOMM Incorporated - Applicants: QUALCOMM Incorporated - Inventors: Jing Lei; Wanshi Chen - Web page: https://patentgrep.com/patent/US11452141B2 ## CPC - H04W 74/0833: Random access procedures, e.g. with 4-step access - H04W 72/23: in the downlink direction of a wireless link, i.e. towards a terminal - H04W 74/0836: with 2-step access - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract Aspects described herein relate to transmitting, to a base station, a random access message in a two-step random access procedure, and receiving, from the base station, a response message for the random access message in the two-step random access procedure, wherein the response message is formatted based at least in part on at least one of a use case associated with the random access message and whether the random access message is successfully received. ## Claims ### Claim 1 A method for wireless communication, by a user equipment (UE), comprising: transmitting, by the UE to a base station, a random access message that includes a common control channel associated with a first identifier of the UE; and receiving, from the base station, a response message responsive to the random access message, wherein the response message is in a first format or a second format depending on whether at least a portion of the random access message is to be retransmitted, wherein the first format includes contention resolution information, indicating the first identifier, and a cell radio network temporary identifier (C-RNTI), wherein the second format is associated with a cyclic redundancy check (CRC) scrambled by a second identifier, different from the C-RNTI and different from the first identifier, the second format instructing the UE to retransmit at least the portion of the random access message. ### Claim 2 (depends on 1) The method of claim 1, wherein the response message in the first format comprises downlink control information that includes a downlink assignment for a downlink shared channel, and wherein a cyclic redundancy check (CRC) of the downlink control information is scrambled at least based on the C-RNTI. ### Claim 3 (depends on 1) The method of claim 1, wherein the response message in the second format further comprises at least one of an uplink grant, a timing advance, or a random access preamble identifier (RAPID). ### Claim 4 (depends on 1) The method of claim 1, wherein a use case associated with the random access message corresponds to transmitting a RRC connection request and a status report, wherein the response message is formatted to be in the first format or the second format further based at least in part on the use case. ### Claim 5 (depends on 1) The method of claim 1, wherein the response message in the first format further includes at least one of a power control command or additional signaling information. ### Claim 6 (depends on 1) The method of claim 1, wherein a payload portion of the random access message includes the common control channel. ### Claim 7 (depends on 1) The method of claim 1, wherein transmitting the random access message is part of a two-step random access procedure, and wherein the random access message includes a preamble portion and a payload portion. ### Claim 8 (depends on 7) The method of claim 7, wherein the response message in the second format instructing the UE to retransmit at least one of the preamble portion or the payload portion. ### Claim 9 (depends on 8) The method of claim 8, further comprising retransmitting at least one of the preamble portion or the payload portion of the random access message over resources assigned by uplink grant in the response message. ### Claim 10 (depends on 9) The method of claim 9, further comprising retransmitting at least the payload portion of the random access message over resources indicated in broadcast system information or dynamically granted resources signaled by downlink control information from the base station. ### Claim 11 (depends on 7) The method of claim 7, wherein the response message in the second format further includes at least one of a power control command or additional signaling information. ### Claim 12 (depends on 1) The method of claim 1, wherein the response message is formatted to be in the first format or the second format further based at least in part on content of the random access message. ### Claim 13 An apparatus for wireless communication, comprising: a transceiver; a memory configured to store instructions; and one or more processors communicatively coupled with the transceiver and the memory, wherein the one or more processors are configured to: transmit, to a base station, a random access message that includes a common control channel associated with a first identifier of the apparatus; and receive, from the base station, a response message responsive to the random access message, wherein the response message is in a first format or a second format depending on whether at least a portion of the random access message is to be retransmitted, wherein the first format includes contention resolution information, indicating the first identifier, and a cell radio network temporary identifier (C-RNTI), wherein the second format is associated with a cyclic redundancy check (CRC) scrambled by a second identifier, different from the C-RNTI and different from the first identifier, the second format instructing the apparatus to retransmit at least a portion of the random access message. ### Claim 14 (depends on 13) The apparatus of claim 13, wherein the response message in the first format comprises downlink control information that includes a downlink assignment for a downlink shared channel, and wherein a cyclic redundancy check (CRC) of the downlink control information is scrambled at least based on the C-RNTI. ### Claim 15 (depends on 13) The apparatus of claim 13, the response message in the second format further comprises at least one of an uplink grant, a timing advance, or a random access preamble identifier (RAPID). ### Claim 16 (depends on 13) The apparatus of claim 13, wherein a use case associated with the random access message corresponds to transmitting a RRC connection request and a status report, wherein the response message is formatted to be in the first format or the second format further based at least in part on the use case. ### Claim 17 (depends on 13) The apparatus of claim 13, wherein the response message in the first format further includes at least one of a power control command or additional signaling information. ### Claim 18 (depends on 13) The apparatus of claim 13, wherein a payload portion of the random access message includes the common control channel. ### Claim 19 (depends on 13) The apparatus of claim 13, wherein transmitting the random access message is part of a two-step random access procedure, and wherein the random access message includes a preamble portion and a payload portion. ### Claim 20 (depends on 19) The apparatus of claim 19, wherein the response message in the second format instructing the apparatus to retransmit at least one of the preamble portion or the payload portion. ### Claim 21 (depends on 20) The apparatus of claim 20, wherein the one or more processors are further configured to retransmit at least one of the preamble portion or the payload portion of the random access message over resources assigned by an uplink grant in the response message. ### Claim 22 (depends on 21) The apparatus of claim 21, wherein the one or more processors are further configured to retransmit at least the payload portion of the random access message over resources indicated in broadcast system information or dynamically granted resources signaled by downlink control information from the base station. ### Claim 23 (depends on 19) The apparatus of claim 19, wherein the response message in the second format further includes at least one of a power control command or additional signaling information. ### Claim 24 An apparatus for wireless communication, comprising: means for transmitting, to a base station, a random access message that includes a common control channel associated with a first identifier of the apparatus; and means for receiving, from the base station, a response message responsive to the random access message, wherein the response message is in a first format or a second format depending on whether at least a portion of the random access message is to be retransmitted, wherein the first format includes contention resolution information, indicating the first identifier, and a cell radio network temporary identifier (C-RNTI), wherein the second format is associated with a cyclic redundancy check (CRC) scrambled by a second identifier, different from the C-RNTI and different from the first identifier, the second format instructing the apparatus to retransmit at least a portion of the random access message. ### Claim 25 (depends on 24) The apparatus of claim 24, wherein the response message in the first format comprises downlink control information that includes a downlink assignment for a downlink shared channel, and wherein a cyclic redundancy check (CRC) of the downlink control information is scrambled at least based on the C-RNTI. ### Claim 26 (depends on 24) The apparatus of claim 24, the response message in the second format further comprises at least one of an uplink grant, a timing advance, or a random access preamble identifier (RAPID). ### Claim 27 (depends on 24) The apparatus of claim 24, wherein a use case associated with the random access message corresponds to transmitting a RRC connection request and a status report, wherein the response message is formatted to be in the first format or the second format further based at least in part on the use case, and wherein the response message further includes at least one of a power control command or additional signaling information. ### Claim 28 A non-transitory computer-readable medium, comprising code executable by one or more processors for wireless communication by a user equipment (UE), the code comprising code for: transmitting, by the UE to a base station, a random access message that includes a common control channel associated with a first identifier of the UE; and receiving, from the base station, a response message responsive to the random access message, wherein the response message is in a first format or a second format depending on whether at least a portion of the random access message is to be retransmitted, wherein the first format includes contention resolution information, indicating the first identifier, and a cell radio network temporary identifier (C-RNTI), wherein the second format is associated with a cyclic redundancy check (CRC) scrambled by a second identifier, different from the C-RNTI and different from the first identifier, the second format instructing the UE to retransmit at least a portion of the random access message. ### Claim 29 (depends on 28) The non-transitory computer-readable medium of claim 28, wherein the response message in the first format comprises downlink control information that includes a downlink assignment for a downlink shared channel, and wherein a cyclic redundancy check (CRC) of the downlink control information is scrambled at least based on the C-RNTI. ### Claim 30 (depends on 28) The non-transitory computer-readable medium of claim 28, the response message in the second format further comprises at least one of an uplink grant, a timing advance, or a random access preamble identifier (RAPID). ### Claim 31 (depends on 28) The non-transitory computer-readable medium of claim 28, wherein a use case associated with the random access message corresponds to transmitting a RRC connection request and a status report, wherein the response message is formatted to be in the first format or the second format further based at least in part on the use case, and wherein the response message further includes at least one of a power control command or additional signaling information.