# US 12,114,356 B2 · Fallback procedures for two-step random access procedures > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,114,356 B2 - Document ID: US12114356B2 - Status: Granted - Kind: B2 - Application number: 18/356,203 - Filed: 2023-07-20 - Published: 2023-11-16 - Granted: 2024-10-08 - Earliest claimed: 2019-02-08 - Assignees: QUALCOMM Incorporated - Applicants: QUALCOMM Incorporated - Inventors: Jing Lei; Linhai He; Hung Dinh Ly; Seyong Park; Naga Bhushan; Ying Wang; Wanshi Chen; Joseph Binamira Soriaga - Web page: https://patentgrep.com/patent/US12114356B2 ## CPC - H04W 74/0808: using carrier sensing, e.g. carrier sense multiple access [CSMA] - H04L 1/1819: {with retransmission of additional or different redundancy} - H04L 1/189: {Transmission or retransmission of more than one copy of a message} - H04L 1/1893: {Physical mapping arrangements (physical resource mapping in general H04L5/00)} - H04L 5/0051: {of dedicated pilots, i.e. pilots destined for a single user or terminal} - H04L 5/0055: {Physical resource allocation for ACK/NACK (for physical mapping arrangements in ARQ protocols H04L1/1861)} - H04L 5/10: with dynamo-electric generation of carriers; with mechanical filters or demodulators - H04W 24/08: Testing, {supervising or monitoring} using real traffic - H04W 72/23: in the downlink direction of a wireless link, i.e. towards a terminal - H04W 74/0833: Random access procedures, e.g. with 4-step access - H04W 74/0836: with 2-step access - H04W 76/27: Transitions between radio resource control [RRC] states - H04W 80/02: Data link layer protocols - H04L 5/0023: {Time-frequency-space} - H04W 74/0838: using contention-free random access [CFRA] - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract Fallback procedures for user equipments (UEs) are described that provide efficient fallback to a four-step random access procedure from a two-step random access procedure. For example, after transmitting a first message of a two-step random access procedure, a UE may start a fallback timer or counter and monitor for a second message of the two-step random access procedure for the duration of the fallback timer or counter. At the expiration of the fallback timer or counter, the UE may fall back to a four-step random access procedure. In some cases, the UE may transmit multiple repetitions of the first message and monitor for responses after transmitting the repetitions or after each repetition. Additionally, or alternatively, the base station may transmit an explicit signal to the UE that may signal to the UE to perform a fallback procedure at a beginning or middle of a random access procedure. ## Claims ### Claim 1 A user equipment (UE) for wireless communication, comprising: one or more memories storing processor-executable code; and one or more processors coupled with the one or more memories and individually or collectively operable to execute the code to cause the UE to: transmit, in accordance with a first transmission parameter, a first portion of a plurality of messages of a random access procedure to a network device, wherein the first portion comprises a first set of bits; transmit, in accordance with a second transmission parameter that is different from the first transmission parameter, a second portion of the plurality of messages of the random access procedure to the network device, wherein the second portion comprises a second set of bits that is different from the first set of bits for a soft combination procedure; and monitor for a response to one or more of the first portion of the plurality of messages or the second portion of the plurality of messages of the random access procedure from the network device. ### Claim 2 (depends on 1) The UE of claim 1, wherein the first transmission parameter is a first numerology and the second transmission parameter is a second numerology that is different from the first numerology, and wherein, to transmit the first portion of the plurality of messages and to transmit the second portion of the plurality of messages, the one or more processors are individually or collectively operable to execute the code to cause the UE to: transmit the first portion of the plurality of messages in accordance with the first numerology; and transmit the second portion of the plurality of messages in accordance with the second numerology. ### Claim 3 (depends on 1) The UE of claim 1, wherein the first transmission parameter is a first portion of a carrier and the second transmission parameter is a second portion of the carrier that is different from the first portion of the carrier, and wherein, to transmit the first portion of the plurality of messages and to transmit the second portion of the plurality of messages, the one or more processors are individually or collectively operable to execute the code to cause the UE to: transmit the first portion of the plurality of messages on the first portion of the carrier; and transmit the second portion of the plurality of messages on the second portion of the carrier. ### Claim 4 (depends on 1) The UE of claim 1, wherein the first transmission parameter is a first bandwidth part and the second transmission parameter is a second bandwidth part that is different from the first bandwidth part, and wherein, to transmit the first portion of the plurality of messages and to transmit the second portion of the plurality of messages, the one or more processors are individually or collectively operable to execute the code to cause the UE to: transmit the first portion of the plurality of messages on the first bandwidth part; and transmit the second portion of the plurality of messages on the second bandwidth part. ### Claim 5 (depends on 1) The UE of claim 1, wherein the first transmission parameter is a first power control scheme and the second transmission parameter is a second power control scheme that is different from the first power control scheme, and wherein, to transmit the first portion of the plurality of messages and to transmit the second portion of the plurality of messages, the one or more processors are individually or collectively operable to execute the code to cause the UE to: transmit the first portion of the plurality of messages in accordance with the first power control scheme; and transmit the second portion of the plurality of messages in accordance with the second power control scheme. ### Claim 6 (depends on 1) The UE of claim 1, wherein the first transmission parameter is a first preamble sequence and the second transmission parameter is a second preamble sequence that is different from the first preamble sequence, and wherein, to transmit the first portion of the plurality of messages and to transmit the second portion of the plurality of messages, the one or more processors are individually or collectively operable to execute the code to cause the UE to: transmit the first portion of the plurality of messages with the first preamble sequence; and transmit the second portion of the plurality of messages with the second preamble sequence. ### Claim 7 (depends on 1) The UE of claim 1, wherein the first transmission parameter is a first sampling rate and the second transmission parameter is a second sampling rate that is different from the first sampling rate, and wherein, to transmit the first portion of the plurality of messages and to transmit the second portion of the plurality of messages, the one or more processors are individually or collectively operable to execute the code to cause the UE to: transmit the first portion of the plurality of messages in accordance with the first sampling rate; and transmit the second portion of the plurality of messages in accordance with the second sampling rate. ### Claim 8 (depends on 1) The UE of claim 1, wherein the first transmission parameter is a first beam and the second transmission parameter is a second beam that is different from the first beam, and wherein, to transmit the first portion of the plurality of messages and to transmit the second portion of the plurality of messages, the one or more processors are individually or collectively operable to execute the code to cause the UE to: transmit the first portion of the plurality of messages on the first beam; and transmit the second portion of the plurality of messages on the second beam. ### Claim 9 (depends on 1) The UE of claim 1, wherein the soft combination procedure comprises chase combining, incremental redundancy, or a combination thereof. ### Claim 10 (depends on 1) The UE of claim 1, wherein the first portion of the plurality of messages comprises an initial message of the random access procedure and the second portion comprises a second message that is a repetition of the initial message of the random access procedure. ### Claim 11 (depends on 10) The UE of claim 10, wherein the initial message of the random access procedure is the initial message of a two-step random access procedure. ### Claim 12 (depends on 10) The UE of claim 10, wherein the repetition of the initial message of the random access procedure is transmitted before receipt of a random access response. ### Claim 13 (depends on 1) The UE of claim 1, wherein the first portion comprises a preamble of a message of the random access procedure and the second portion comprises a data payload of the message of the random access procedure, and wherein the plurality of messages comprises one or more repetitions of the message of the random access procedure. ### Claim 14 (depends on 13) The UE of claim 13, wherein the preamble of the message of the random access procedure and the data payload of the message of the random access procedure are transmitted in accordance with different numerologies, transmitted on different portions of a carrier, transmitted on different bandwidth parts, transmitted in accordance with different power control schemes, transmitted in accordance with different carrier spacings, transmitted in accordance with different sampling rates, transmitted on different beams, or a combination thereof. ### Claim 15 (depends on 13) The UE of claim 13, wherein the first transmission parameter is a first set of resources associated with a first numerology and the second transmission parameter is a second set of resources associated with a second numerology, wherein the second set of resources partially overlaps with the first set of resources or does not overlap with the first set of resources, and wherein, to transmit the first portion of the plurality of messages and to transmit the second portion of the plurality of messages, the one or more processors are individually or collectively operable to execute the code to cause the UE to: transmit the first portion of the plurality of messages via the first set of resources in accordance with the first numerology; and transmit the second portion of the plurality of messages via the second set of resources in accordance with the second numerology. ### Claim 16 (depends on 1) The UE of claim 1, wherein the one or more processors are individually or collectively further operable to execute the code to cause the UE to: receive, from the network device, a system information message to configure the first transmission parameter and the second transmission parameter from a set of parameters, the set of parameters comprising different numerologies, different portions of a carrier, different bandwidth parts, different power control schemes, different carrier spacings, different preamble sequences, different sampling rates, different sets of bits for the soft combination procedure, different beams, or a combination thereof, wherein, to transmit the first portion of the plurality of messages and to transmit the second portion of the plurality of messages, the one or more processors are individually or collectively operable to execute the code to cause the UE to transmit the first portion and the second portion in accordance with the system information message. ### Claim 17 (depends on 1) The UE of claim 1, wherein the one or more processors are individually or collectively further operable to execute the code to cause the UE to: receive, from the network device, a system information message to configure a repetition pattern for the plurality of messages, a repetition periodicity for the plurality of messages, a repetition threshold for the plurality of messages, a time window parameter of the random access procedure, or a starting position for a time window of the random access procedure, wherein, to transmit the first portion of the plurality of messages and to transmit the second portion of the plurality of messages, the one or more processors are individually or collectively operable to execute the code to cause the UE to transmit the first portion and the second portion in accordance with the system information message. ### Claim 18 (depends on 17) The UE of claim 17, wherein the system information message to configure the repetition threshold is based at least in part on a quality of service, a traffic load, a radio resource control state of the UE, a payload size, or a combination thereof. ### Claim 19 A method for wireless communication by a user equipment (UE), comprising: transmitting, in accordance with a first transmission parameter, a first portion of a plurality of messages of a random access procedure to a network device, wherein the first portion comprises a first set of bits; transmitting, in accordance with a second transmission parameter that is different from the first transmission parameter, a second portion of the plurality of messages of the random access procedure to the network device, wherein the second portion comprises a second set of bits that is different from the first set of bits for a soft combination procedure; and monitoring for a response to one or more of the first portion of the plurality of messages or the second portion of the plurality of messages of the random access procedure from the network device. ### Claim 20 (depends on 19) The method of claim 19, wherein the first transmission parameter is a first numerology and the second transmission parameter is a second numerology that is different from the first numerology, and wherein transmitting the first portion of the plurality of messages and transmitting the second portion of the plurality of messages comprise: transmitting the first portion of the plurality of messages in accordance with the first numerology; and transmitting the second portion of the plurality of messages in accordance with the second numerology. ### Claim 21 (depends on 19) The method of claim 19, wherein the first transmission parameter is a first portion of a carrier and the second transmission parameter is a second portion of the carrier that is different from the first portion of the carrier, and wherein transmitting the first portion of the plurality of messages and transmitting the second portion of the plurality of messages comprise: transmitting the first portion of the plurality of messages on the first portion of the carrier; and transmitting the second portion of the plurality of messages on the second portion of the carrier. ### Claim 22 (depends on 19) The method of claim 19, wherein the first transmission parameter is a first bandwidth part and the second transmission parameter is a second bandwidth part that is different from the first bandwidth part, and wherein transmitting the first portion of the plurality of messages and transmitting the second portion of the plurality of messages comprise: transmitting the first portion of the plurality of messages on the first bandwidth part; and transmitting the second portion of the plurality of messages on the second bandwidth part. ### Claim 23 (depends on 19) The method of claim 19, wherein the first transmission parameter is a first power control scheme and the second transmission parameter is a second power control scheme that is different from the first power control scheme, and wherein transmitting the first portion of the plurality of messages and transmitting the second portion of the plurality of messages comprise: transmitting the first portion of the plurality of messages in accordance with the first power control scheme; and transmitting the second portion of the plurality of messages in accordance with the second power control scheme. ### Claim 24 (depends on 19) The method of claim 19, wherein the first transmission parameter is a first preamble sequence and the second transmission parameter is a second preamble sequence that is different from the first preamble sequence, and wherein transmitting the first portion of the plurality of messages and transmitting the second portion of the plurality of messages comprise: transmitting the first portion of the plurality of messages with the first preamble sequence; and transmitting the second portion of the plurality of messages with the second preamble sequence. ### Claim 25 (depends on 19) The method of claim 19, wherein the first transmission parameter is a first sampling rate and the second transmission parameter is a second sampling rate that is different from the first sampling rate, and wherein transmitting the first portion of the plurality of messages and transmitting the second portion of the plurality of messages comprise: transmitting the first portion of the plurality of messages in accordance with the first sampling rate; and transmitting the second portion of the plurality of messages in accordance with the second sampling rate. ### Claim 26 (depends on 19) The method of claim 19, wherein the first transmission parameter is a first beam and the second transmission parameter is a second beam that is different from the first beam, and wherein transmitting the first portion of the plurality of messages and transmitting the second portion of the plurality of messages comprise: transmitting the first portion of the plurality of messages on the first beam; and transmitting the second portion of the plurality of messages on the second beam. ### Claim 27 (depends on 19) The method of claim 19, wherein the soft combination procedure comprises chase combining, incremental redundancy, or a combination thereof. ### Claim 28 (depends on 19) The method of claim 19, wherein the first portion of the plurality of messages comprises an initial message of the random access procedure and the second portion comprises a second message that is a repetition of the initial message of the random access procedure. ### Claim 29 (depends on 19) The method of claim 19, wherein the first portion comprises a preamble of a message of the random access procedure and the second portion comprises a data payload of the message of the random access procedure, and wherein the plurality of messages comprises one or more repetitions of the message of the random access procedure. ### Claim 30 (depends on 19) The method of claim 19, further comprising: receiving, from the network device, a system information message to configure the first transmission parameter and the second transmission parameter from a set of parameters, the set of parameters comprising different numerologies, different portions of a carrier, different bandwidth parts, different power control schemes, different carrier spacings, different preamble sequences, different sampling rates, different sets of bits for the soft combination procedure, different beams, or a combination thereof, wherein transmitting the first portion of the plurality of messages and transmitting the second portion of the plurality of messages comprise transmitting the first portion and the second portion in accordance with the system information message. ### Claim 31 (depends on 19) The method of claim 19, further comprising: receiving, from the network device, a system information message to configure a repetition pattern for the plurality of messages, a repetition periodicity for the plurality of messages, a repetition threshold for the plurality of messages, a time window parameter of the random access procedure, or a starting position for a time window of the random access procedure, wherein transmitting the first portion of the plurality of messages and transmitting the second portion of the plurality of messages comprise transmitting the first portion and the second portion in accordance with the system information message. ### Claim 32 A non-transitory computer-readable medium storing code for wireless communication, the code comprising instructions executable by one or more processors to: transmit, in accordance with a first transmission parameter, a first portion of a plurality of messages of a random access procedure to a network device, wherein the first portion comprises a first set of bits; transmit, in accordance with a second transmission parameter that is different from the first transmission parameter, a second portion of the plurality of messages of the random access procedure to the network device, wherein the second portion comprises a second set of bits that is different from the first set of bits for a soft combination procedure; and monitor for a response to one or more of the first portion of the plurality of messages or the second portion of the plurality of messages of the random access procedure from the network device. ### Claim 33 A user equipment (UE) for wireless communication, comprising: means for transmitting, in accordance with a first transmission parameter, a first portion of a plurality of messages of a random access procedure to a network device, wherein the first portion comprises a first set of bits; means for transmitting, in accordance with a second transmission parameter that is different from the first transmission parameter, a second portion of the plurality of messages of the random access procedure to the network device, wherein the second portion comprises a second set of bits that is different from the first set of bits for a soft combination procedure; and means for monitoring for a response to one or more of the first portion of the plurality of messages or the second portion of the plurality of messages of the random access procedure from the network device.