# US 2020/0288504 A1 · 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 2020/0288504 A1 - Document ID: US20200288504A1 - Status: Published application - Kind: A1 - Application number: 16/785,345 - Filed: 2020-02-07 - Published: 2020-09-10 - Earliest claimed: 2019-03-04 - Assignees: QUALCOMM Incorporated - Applicants: QUALCOMM Incorporated - Inventors: Jing Lei; Wanshi Chen - Web page: https://patentgrep.com/patent/US20200288504A1 ## 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 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 a use case associated with the random access message and whether the random access message is successfully received. ### Claim 2 (depends on 1) The method of claim 1, wherein the response message includes downlink control information including 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 a random access identifier associated with the random access message sent by the UE. ### Claim 3 (depends on 2) The method of claim 2, wherein the response message further includes, based on a detection status of a preamble portion and a payload portion of the random access message as being received by the base station, contention resolution information including at least an identifier of the UE. ### Claim 4 (depends on 3) The method of claim 3, wherein the use case associated with the random access message corresponds to transmitting a RRC connection request and a status report, and wherein the response message further includes a second identifier for the user equipment to use in subsequent transmissions. ### Claim 5 (depends on 4) The method of claim 4, wherein the response message further includes at least one of a timing advance command, a power control command, or additional signaling information. ### Claim 6 (depends on 3) The method of claim 3, wherein the payload portion of the random access message includes a common control channel associated with a different identifier of the UE to facilitate contention resolution. ### Claim 7 (depends on 1) The method of claim 1, wherein the response message includes, based on a detection status of at least one of a preamble portion of the random access message or a payload portion of the random access message as not being received by the base station, an identifier of a user equipment for which at least one of a preamble portion of the random access message or a payload portion of the random access message is not received, and an indication to retransmit at least one of the preamble portion or the payload portion. ### Claim 8 (depends on 7) The method of claim 7, wherein the response message further includes an uplink grant for retransmitting 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 the uplink grant. ### 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 further includes at least one of a timing advance command, a power control command, or additional signaling information. ### Claim 12 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 in a two-step random access procedure; and receive, 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 a use case associated with the random access message and whether the random access message is successfully received. ### Claim 13 (depends on 12) The apparatus of claim 12, wherein the response message includes downlink control information including 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 a random access identifier associated with the random access message. ### Claim 14 (depends on 13) The apparatus of claim 13, wherein the response message further includes, based on a detection status of a preamble portion and a payload portion of the random access message as being received by the base station, contention resolution information including at least an identifier of the apparatus. ### Claim 15 (depends on 14) The apparatus of claim 14, wherein the use case associated with the random access message corresponds to transmitting a RRC connection request and a status report, and wherein the response message further includes a second identifier for the user equipment to use in subsequent transmissions. ### Claim 16 (depends on 15) The apparatus of claim 15, wherein the response message further includes at least one of a timing advance command, a power control command, or additional signaling information. ### Claim 17 (depends on 14) The apparatus of claim 14, wherein the payload portion of the random access message includes a common control channel associated with a different identifier of the apparatus to facilitate contention resolution. ### Claim 18 (depends on 12) The apparatus of claim 12, wherein the response message includes, based on a detection status of at least one of a preamble portion of the random access message or a payload portion of the random access message as not being received by the base station, an identifier of a user equipment for which at least one of a preamble portion of the random access message or a payload portion of the random access message is not received, and an indication to retransmit at least one of the preamble portion or the payload portion. ### Claim 19 (depends on 18) The apparatus of claim 18, wherein the response message further includes an uplink grant for retransmitting at least one of the preamble portion or the payload portion. ### Claim 20 (depends on 19) The apparatus of claim 19, 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 the uplink grant. ### Claim 21 (depends on 20) The apparatus of claim 20, 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 22 (depends on 18) The apparatus of claim 18, wherein the response message further includes at least one of a timing advance command, a power control command, or additional signaling information. ### Claim 23 An apparatus for wireless communication, comprising: means for transmitting, to a base station, a random access message in a two-step random access procedure; and means for 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 a use case associated with the random access message and whether the random access message is successfully received. ### Claim 24 (depends on 23) The apparatus of claim 23, wherein the response message includes downlink control information including 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 a random access identifier associated with the random access message. ### Claim 25 (depends on 24) The apparatus of claim 24, wherein the response message further includes, based on a detection status of a preamble portion and a payload portion of the random access message as being received by the base station, contention resolution information including at least an identifier of the apparatus. ### Claim 26 (depends on 25) The apparatus of claim 25, wherein the use case associated with the random access message corresponds to transmitting a RRC connection request and a status report, and wherein the response message further includes at least one of a second identifier for the user equipment to use in subsequent transmissions, a timing advance command, a power control command, or additional signaling information. ### Claim 27 A 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 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 a use case associated with the random access message and whether the random access message is successfully received. ### Claim 28 (depends on 27) The computer-readable medium of claim 27, wherein the response message includes downlink control information including 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 a random access identifier associated with the random access message sent by the UE. ### Claim 29 (depends on 28) The computer-readable medium of claim 28, wherein the response message further includes, based on a detection status of a preamble portion and a payload portion of the random access message as being received by the base station, contention resolution information including at least an identifier of the UE. ### Claim 30 (depends on 29) The computer-readable medium of claim 29, wherein the use case associated with the random access message corresponds to transmitting a RRC connection request and a status report, and wherein the response message further includes at least one of a second identifier for the user equipment to use in subsequent transmissions, a timing advance command, a power control command, or additional signaling information.