# US 11,445,561 B2 · Techniques for retransmitting 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 11,445,561 B2
- Document ID: US11445561B2
- Status: Granted
- Kind: B2
- Application number: 16/783,985
- Filed: 2020-02-06
- Published: 2020-08-27
- Granted: 2022-09-13
- Earliest claimed: 2019-02-27
- Assignees: QUALCOMM Incorporated
- Applicants: QUALCOMM Incorporated
- Inventors: Jing Lei; Wanshi Chen; Peter Gaal; Joseph Binamira Soriaga
- Web page: https://patentgrep.com/patent/US11445561B2

## CPC

- H04B 7/06964: {Re-selection of one or more beams after beam failure}
- H04B 7/088: {using beam selection}
- H04L 1/0003: {by switching between different modulation schemes}
- H04L 1/0009: {by adapting the channel coding (H04L1/1812 takes precedence)}
- H04L 1/0025: {Transmission of mode-switching indication}
- H04L 1/06: using space diversity
- H04L 1/1671: {the supervisory signal being transmitted together with control information}
- H04L 1/1816: {with retransmission of the same, encoded, message}
- H04L 1/1825: Adaptation of specific ARQ protocol parameters according to transmission conditions
- H04L 1/1864: {ARQ related signaling (H04L1/1607 takes precedence)}
- H04L 1/1893: {Physical mapping arrangements (physical resource mapping in general H04L5/00)}
- H04W 72/046: {the resource being in the space domain, e.g. beams}
- H04W 72/23: in the downlink direction of a wireless link, i.e. towards a terminal
- H04W 74/0836: with 2-step access
- H04W 76/18: Management of setup rejection or failure
- H04L 2001/0093: {Point-to-multipoint}
- 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

Aspects described herein relate to determining a failure associated with reception, by a base station, of an initial transmission of a random access message transmitted by the UE in a two-step random access procedure, and based on determining the failure situations associated with reception of the random access message, configuring the parameters of a retransmission and/or retransmitting at least a portion of the random access message.

## Claims

### Claim 1

A method for wireless communication, comprising:
determining, by a user equipment (UE), a failure associated with reception, by a base station, of an initial transmission of a random access message transmitted by the UE in a two-step random access procedure; and
transmitting, by the UE to the base station and based on determining the failure, a retransmission of at least a portion of the random access message, the portion of the random access message comprising a payload of the random access message,
wherein the retransmission is transmitted on a different beam than the initial transmission, and a switch to the different beam is based on a response message.

### Claim 2 (depends on 1)

The method of claim 1, wherein the retransmission is a repeat of the random access message.

### Claim 3

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:
determine a failure associated with reception, by a base station, of an initial transmission of a random access message transmitted in a two-step random access procedure; and
transmit, to the base station and based on determining the failure, a retransmission of at least a portion of the random access message, the portion of the random access message comprising a payload of the random access message,
wherein the one or more processors are configured to transmit the retransmission on a different beam than the initial transmission, and a switch to the different beam is based on a response message.

### Claim 4 (depends on 3)

The apparatus of claim 3, wherein the retransmission is a repeat of the random access message.

### Claim 5

A non-transitory computer-readable medium, comprising code executable by one or more processors for wireless communications, the code comprising code for:
determining, by a user equipment (UE), a failure associated with reception, by a base station, of an initial transmission of a random access message transmitted by the UE in a two-step random access procedure; and
transmitting, by the UE to the base station and based on determining the failure, a retransmission of at least a portion of the random access message, the portion of the random access message comprising a payload of the random access message,
wherein the code for transmitting transmits the retransmission on a different beam than the initial transmission, and a switch to the different beam is based on a response message.

### Claim 6 (depends on 5)

The non-transitory computer-readable medium of claim 5, wherein the retransmission is a repeat of the random access message.