# US 11,445,552 B2 · Triggered physical random access channel for new radio unlicensed > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,445,552 B2 - Document ID: US11445552B2 - Status: Granted - Kind: B2 - Application number: 16/735,370 - Filed: 2020-01-06 - Published: 2020-07-30 - Granted: 2022-09-13 - Earliest claimed: 2019-01-25 - Assignees: QUALCOMM Incorporated - Applicants: QUALCOMM Incorporated - Inventors: Jing Sun; Andrei Dragos Radulescu; Ananta Narayanan Thyagarajan; Pravjyot Singh Deogun; Xiaoxia Zhang; Kapil Bhattad - Web page: https://patentgrep.com/patent/US11445552B2 ## CPC - H04W 74/006: {in the downlink, i.e. towards the terminal} - H04W 74/0833: Random access procedures, e.g. with 4-step access - H04W 72/0446: Resources in time domain, e.g. slots or frames - H04W 72/0453: Resources in frequency domain, e.g. a carrier in FDMA - H04W 72/23: in the downlink direction of a wireless link, i.e. towards a terminal - H04W 74/0808: using carrier sensing, e.g. carrier sense multiple access [CSMA] - 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) ## Abstract Methods, systems, and devices for wireless communications are described. A user equipment (UE) may obtain a signal received over a wireless channel, the signal configuring one or more random access parameters for the wireless channel. The UE may obtain a downlink control signal over the wireless channel, wherein the downlink control signal comprises an indication of a trigger and a location of one or more random access occasions for the UE. The UE may output, based at least in part on the downlink control signal, a random access signal for transmission on the wireless channel during at least one of the one or more random access occasions and according to the one or more random access parameters and the location. The UE may establish a connection with a base station based at least in part on the random access signal. ## Claims ### Claim 1 A method for wireless communication at a user equipment (UE), comprising: obtaining a signal received over a wireless channel, the signal configuring one or more random access parameters for the wireless channel; obtaining a downlink control signal over the wireless channel, wherein the downlink control signal comprises an indication of a resource location of a plurality of random access occasions for the UE and a trigger for the plurality of random access occasions; outputting, based at least in part on the downlink control signal, a random access signal for transmission on the wireless channel during at least one of the plurality of random access occasions and according to the one or more random access parameters and the resource location; outputting, for transmission to a network device, an indication of intent to transmit the random access signal during the at least one of the plurality of random access occasions, wherein the indication of intent to transmit the random access signal is output for transmission prior to the plurality of random access occasions used for transmission of the random access signal and the indication of intent indicates to the network device to refrain from reclaiming or rescheduling the at least one of the plurality of random access occasions; and establishing a connection with the network device based at least in part on the random access signal. ### Claim 2 (depends on 1) The method of claim 1, further comprising: identifying, based at least in part on the downlink control signal, a timing offset between a reference point and a time instance where random access occasions are triggered, wherein the reference point is either a reception of the downlink control signal or is network-configured via a common control signaling reference point. ### Claim 3 (depends on 1) The method of claim 1, further comprising: updating at least one of the one or more random access parameters based at least in part on the downlink control signal. ### Claim 4 (depends on 1) The method of claim 1, wherein the downlink control signal is associated with a subset of the plurality of random access occasions and a corresponding subset of random access preambles. ### Claim 5 (depends on 1) The method of claim 1, further comprising: initiating a listen-before-talk procedure prior to outputting the random access signal for transmission. ### Claim 6 (depends on 1) The method of claim 1, wherein the downlink control signal comprises at least one of a first timing offset for a random access occasion relative to the downlink control signal, a second timing offset for a random access occasion relative to a reference point indicated by a network, a time-frequency resource for the random access signal, an index value corresponding to a time-frequency resource for the random access signal, a preamble configuration for the random access signal, a time duration in which the plurality of random access occasions are triggered, a configuration to map one or more synchronization signal blocks to the plurality of random access occasions and random access preambles, an indication of a subset of the plurality of random access occasions, an indication of a symbol occurring prior to a random access occasion in which an intent to transmit transmission will occur, a listen-before-talk configuration associated with the plurality of random access occasions, or a combination thereof. ### Claim 7 (depends on 1) The method of claim 1, wherein the one or more random access parameters comprise at least one of a random access signal waveform configuration, a format for the random access signal, a time-frequency resource for the random access signal, a repetition factor for a pattern of a plurality of random access occasions, a preamble configuration for the random access signal, a timing advance for the random access signal, an indication of a symbol occurring prior to a random access occasion in which an intent to transmit transmission will occur, a first timing offset for a random access occasion relative to the downlink control signal, a second timing offset for a random access occasion relative to a reference point indicated by a network, a time duration in which the plurality of random access occasions are triggered, a listen-before-talk configuration associated with the plurality of random access occasions, or a combination thereof. ### Claim 8 (depends on 1) The method of claim 1, wherein the signal configuring the one or more random access parameters comprises an indication of at least one of a control resource set, a search space configuration, a downlink control signal format, or a combination thereof, for obtaining the downlink control signal. ### Claim 9 (depends on 1) The method of claim 1, wherein the signal configuring the one or more random access parameters comprises at least one of a radio resource control signal, a system information signal, or a combination thereof. ### Claim 10 A method for wireless communication at a network device, comprising: outputting a signal for transmission over a wireless channel, the signal configuring one or more random access parameters for the wireless channel; outputting a downlink control signal for transmission over the wireless channel, wherein the downlink control signal comprises an indication of a resource location of a plurality of random access occasions for a user equipment (UE) and a trigger for the plurality of random access occasions; obtaining, based at least in part on the downlink control signal, a random access signal received over the wireless channel during at least one of the plurality of random access occasions and according to the one or more random access parameters and the resource location; obtaining, prior to obtaining the random access signal, an indication of intent to transmit the random access signal during the at least one of the plurality of random access occasions, wherein the indication of intent to transmit the random access signal is obtained prior to the plurality of random access occasions used for transmission of the random access signal; refraining from reclaiming or rescheduling the at least one of the plurality of random access occasions based at least in part on the indication of intent; and establishing a connection with the UE based at least in part on the random access signal. ### Claim 11 (depends on 10) The method of claim 10, further comprising: configuring the downlink control signal to indicate a timing offset between a reference point and a time instance when random access occasions are triggered, wherein the reference point is either the transmission of the downlink control signal or is network-configured via a common control signaling reference point. ### Claim 12 (depends on 10) The method of claim 10, further comprising: configuring the downlink control signal to indicate an update for at least one of the one or more random access parameters. ### Claim 13 (depends on 10) The method of claim 10, wherein the downlink control signal is associated with a subset of the plurality of random access occasions and a corresponding subset of random access preambles. ### Claim 14 (depends on 10) The method of claim 10, further comprising: initiating a listen-before-talk procedure prior to outputting at least one of the signal, the downlink control signal, or a combination thereof, for transmission. ### Claim 15 (depends on 10) The method of claim 10, wherein the downlink control signal comprises at least one of a first timing offset for a random access occasion relative to the downlink control signal, a second timing offset for a random access occasion relative to a reference point indicated by a network, a time-frequency resource for the random access signal, an index value corresponding to a time-frequency resource for the random access signal, a preamble configuration for the random access signal, a time duration in which the plurality of random access occasions are triggered, a configuration to map one or more synchronization signal blocks to the plurality of random access occasions and random access preambles, an indication of a subset of the plurality of random access occasions, an indication of a symbol occurring prior to a random access occasion in which an intent to transmit transmission will occur, a listen-before-talk configuration associated with the plurality of random access occasions, or a combination thereof. ### Claim 16 (depends on 10) The method of claim 10, wherein the one or more random access parameters comprise at least one of a random access signal waveform configuration, a format for the random access signal, a time-frequency resource for the random access signal, a repetition factor for a pattern of a plurality of random access occasions, a preamble configuration for the random access signal, a timing advance for the random access signal, an indication of a symbol occurring prior to a random access occasion in which an intent to transmit transmission will occur, a first timing offset for a random access occasion relative to the downlink control signal, a second timing offset for a random access occasion relative to a reference point indicated by a network, a time duration in which the plurality of random access occasions are triggered, a listen-before-talk configuration associated with the plurality of random access occasions, or a combination thereof. ### Claim 17 (depends on 10) The method of claim 10, wherein the signal configuring the one or more random access parameters comprises an indication of at least one of a control resource set, a search space configuration, a downlink control signal format, or a combination thereof, for obtaining the downlink control signal. ### Claim 18 (depends on 10) The method of claim 10, wherein the signal configuring the one or more random access parameters comprises at least one of a radio resource control signal, a system information signal, or a combination thereof. ### Claim 19 An apparatus for wireless communication at a user equipment (UE), comprising: a processor, memory coupled with the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to: obtain a signal received over a wireless channel, the signal configuring one or more random access parameters for the wireless channel; obtain a downlink control signal over the wireless channel, wherein the downlink control signal comprises an indication of a resource location of a plurality of random access occasions for the UE and a trigger for the plurality of random access occasions; output, based at least in part on the downlink control signal, a random access signal for transmission on the wireless channel during at least one of the plurality of random access occasions and according to the one or more random access parameters and the resource location; output, for transmission to a network device, an indication of intent to transmit the random access signal during the at least one of the plurality of random access occasions, wherein the indication of intent to transmit the random access signal is output for transmission prior to the plurality of random access occasions used for transmission of the random access signal and the indication of intent indicates to the network device to refrain from reclaiming or rescheduling the at least one of the plurality of random access occasions; and establish a connection with the network device based at least in part on the random access signal. ### Claim 20 (depends on 19) The apparatus of claim 19, wherein the instructions are further executable by the processor to cause the apparatus to: identify, based at least in part on the downlink control signal, a timing offset between a reference point and a time instance where random access occasions are triggered, wherein the reference point is either a reception of the downlink control signal or is network-configured via a common control signaling reference point. ### Claim 21 (depends on 19) The apparatus of claim 19, wherein the instructions are further executable by the processor to cause the apparatus to: update at least one of the one or more random access parameters based at least in part on the downlink control signal. ### Claim 22 (depends on 19) The apparatus of claim 19, wherein the downlink control signal is associated with a subset of the plurality of random access occasions and a corresponding subset of random access preambles. ### Claim 23 (depends on 19) The apparatus of claim 19, wherein the instructions are further executable by the processor to cause the apparatus to: initiate a listen-before-talk procedure prior to outputting the random access signal for transmission. ### Claim 24 An apparatus for wireless communication at a network device, comprising: a processor, memory coupled with the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to: output a signal for transmission over a wireless channel, the signal configuring one or more random access parameters for the wireless channel; output a downlink control signal for transmission over the wireless channel, wherein the downlink control signal comprises an indication of a resource location of a plurality of random access occasions for a user equipment (UE) and a trigger for the plurality of random access occasions; obtain, based at least in part on the downlink control signal, a random access signal received over the wireless channel during at least one of the plurality of random access occasions and according to the one or more random access parameters and the resource location; obtain, prior to the random access signal, an indication of intent to transmit the random access signal during the at least one of the plurality of random access occasions, wherein the indication of intent to transmit the random access signal is obtained prior to the plurality of random access occasions used for transmission of the random access signal; refrain from reclaiming or rescheduling the at least one of the plurality of random access occasions based at least in part on the indication of intent; and establish a connection with the UE based at least in part on the random access signal. ### Claim 25 (depends on 24) The apparatus of claim 24, wherein the instructions are further executable by the processor to cause the apparatus to: configure the downlink control signal to indicate a timing offset between a reference point and a time instance when random access occasions are triggered, wherein the reference point is either the transmission of the downlink control signal or is network-configured via a common control signaling reference point. ### Claim 26 (depends on 24) The apparatus of claim 24, wherein the instructions are further executable by the processor to cause the apparatus to: configure the downlink control signal to indicate an update for at least one of the one or more random access parameters. ### Claim 27 (depends on 24) The apparatus of claim 24, wherein the downlink control signal is associated with a subset of the plurality of random access occasions and a corresponding subset of random access preambles. ### Claim 28 (depends on 1) The method of claim 1, wherein the plurality of random access occasions are inside a channel occupancy time, outside the channel occupancy time, or any combination thereof. ### Claim 29 (depends on 1) The method of claim 1, wherein the downlink control signal comprises one or more listen-before-talk configurations, the one or more listen-before-talk configurations associated with the plurality of random access occasions being inside a channel occupancy time, outside the channel occupancy time, or any combination thereof.