Ue selection of contention-free and contention-based random access for handover

A method of wireless communication, comprising:

• receiving, at a user equipment (UE), a random access configuration, wherein the random access configuration includes configuration for contention-free random access (CFRA) and contention-based random access (CBRA);
• determining, at the UE, a first random access resource, wherein the first random access resource maps to one or more beams from a target base station;
• initiating, by the UE, a random access request using the CFRA when the first random access resource is a contention-free resource;
• failing, by the UE, to detect a random access response to the random access request using the CFRA prior to a predetermined period of time after the initiating the random access using the CFRA;
• and
• initiating, by the UE, CBRA at a next contention-based resource, wherein the next contention-based resource maps to one or more additional beams of the target base station.

A method of wireless communication, comprising:

• receiving, at a user equipment (UE), a random access configuration, wherein the random access configuration includes configuration for contention-free random access (CFRA) and contention-based random access (CBRA);
• determining, at the UE, a first random access resource, wherein the first random access resource maps to one or more beams from a target base station;
• initiating, by the UE, a random access request using the CFRA when the first random access resource is a contention-free resource;
• and
• initiating, by the UE, the random access request using the CBRA when the first random access resource is a contention-based resource.

A method of wireless communication, comprising:

• receiving, at a target base station, a random access request from a user equipment (UE) using a contention-free random access (CFRA) procedure at one or more beams scheduled for CFRA;
• transmitting, by the target base station, a random access response to the UE identifying a delay until an uplink transmission opportunity;
• detecting, by the target base station, a contention-based random access (CBRA) request from the UE prior to the uplink transmission opportunity;
• and
• reducing, by the target base station, the delay for a next uplink transmission opportunity using CFRA.

A method of wireless communication, comprising:

• receiving, at a target base station, a handover request associated with a user equipment (UE);
• generating, by the target base station, a handover command including a random access configuration, wherein the random access configuration includes configuration for contention-free random access (CFRA) and contention-based random access (CBRA);
• scheduling, by the target base station, one or more beams for CFRA and one or more additional beams for CBRA;
• detecting, by the target base station, handover initiation by the UE using the one or more additional beams for CBRA;
• and
• releasing, by the target base station, schedule of the one or more beams for CFRA.

An apparatus configured for wireless communication, comprising:

• means for receiving, at a user equipment (UE), a random access configuration, wherein the random access configuration includes configuration for contention-free random access (CFRA) and contention-based random access (CBRA);
• means for determining, at the UE, a first random access resource, wherein the first random access resource maps to one or more beams from a target base station;
• means for determining, by the UE, a beam quality associated with the first random access resource;
• and
• means for initiating, by the UE, a random access request using the CBRA when the first random access resource is a contention-free resource, and the beam quality of the first random access resource is below a threshold beam quality.

An apparatus configured for wireless communication, comprising:

• means for receiving, at a user equipment (UE), a random access configuration, wherein the random access configuration includes configuration for contention-free random access (CFRA) and contention-based random access (CBRA);
• means for determining, at the UE, a first random access resource, wherein the first random access resource maps to one or more beams from a target base station;
• means for initiating, by the UE, a random access request using the CFRA when the first random access resource is a contention-free resource;
• means for failing, by the UE, to detect a random access response to the random access request using the CFRA prior to a predetermined period of time after the means for initiating the random access using the CFRA;
• and
• means for initiating, by the UE, CBRA at a next contention-based resource, wherein the next contention-based resource maps to one or more additional beams of the target base station.

An apparatus configured for wireless communication, comprising:

• means for receiving, at a user equipment (UE), a random access configuration, wherein the random access configuration includes configuration for contention-free random access (CFRA) and contention-based random access (CBRA);
• means for determining, at the UE, a first random access resource, wherein the first random access resource maps to one or more beams from a target base station;
• means for initiating, by the UE, a random access request using the CFRA when the first random access resource is a contention-free resource;
• and
• means for initiating, by the UE, the random access request using the CBRA when the first random access resource is a contention-based resource.

An apparatus configured for wireless communication, comprising:

• means for receiving, at a target base station, a random access request from a user equipment (UE) using a contention-free random access (CFRA) procedure at one or more beams scheduled for CFRA;
• means for transmitting, by the target base station, a random access response to the UE identifying a delay until an uplink transmission opportunity;
• means for detecting, by the target base station, a contention-based random access (CBRA) request from the UE prior to the uplink transmission opportunity;
• and
• means for reducing, by the target base station, the delay for a next uplink transmission opportunity using CFRA.

An apparatus configured for wireless communication, comprising:

• means for receiving, at a target base station, a handover request associated with a user equipment (UE);
• means for generating, by the target base station, a handover command including a random access configuration, wherein the random access configuration includes configuration for contention-free random access (CFRA) and contention-based random access (CBRA);
• means for scheduling, by the target base station, one or more beams for CFRA and one or more additional beams for CBRA;
• means for detecting, by the target base station, handover initiation by the UE using the one or more additional beams for CBRA;
• and
• means for releasing, by the target base station, schedule of the one or more beams for CFRA.

A non-transitory computer-readable medium having program code recorded thereon, the program code comprising:

• program code executable by a computer for causing the computer to receive, at a user equipment (UE), a random access configuration, wherein the random access configuration includes configuration for contention-free random access (CFRA) and contention-based random access (CBRA);
• program code executable by the computer for causing the computer to determine, at the UE, a first random access resource, wherein the first random access resource maps to one or more beams from a target base station;
• program code executable by the computer for causing the computer to determine, by the UE, a beam quality associated with the first random access resource;
• and
• program code executable by the computer for causing the computer to initiate, by the UE, a random access request using the CBRA when the first random access resource is a contention-free resource, and the beam quality of the first random access resource is below a threshold beam quality.

A non-transitory computer-readable medium having program code recorded thereon, the program code comprising:

• program code executable by a computer for causing the computer to receive, at a user equipment (UE), a random access configuration, wherein the random access configuration includes configuration for contention-free random access (CFRA) and contention-based random access (CBRA);
• program code executable by the computer for causing the computer to determine, at the UE, a first random access resource, wherein the first random access resource maps to one or more beams from a target base station;
• program code executable by the computer for causing the computer to initiate, by the UE, a random access request using the CFRA when the first random access resource is a contention-free resource;
• program code executable by the computer for causing the computer to fail, by the UE, to detect a random access response to the random access request using the CFRA prior to a predetermined period of time after execution of the program code executable by the computer for causing the computer to initiate the random access using the CFRA;
• and
• program code executable by the computer for causing the computer to initiate, by the UE, CBRA at a next contention-based resource, wherein the next contention-based resource maps to one or more additional beams of the target base station.

A non-transitory computer-readable medium having program code recorded thereon, the program code comprising:

• program code executable by a computer for causing the computer to receive, at a user equipment (UE), a random access configuration, wherein the random access configuration includes configuration for contention-free random access (CFRA) and contention-based random access (CBRA);
• program code executable by the computer for causing the computer to determine, at the UE, a first random access resource, wherein the first random access resource maps to one or more beams from a target base station;
• program code executable by the computer for causing the computer to initiate, by the UE, a random access request using the CFRA when the first random access resource is a contention-free resource;
• and
• program code executable by the computer for causing the computer to initiate, by the UE, the random access request using the CBRA when the first random access resource is a contention-based resource.

A non-transitory computer-readable medium having program code recorded thereon, the program code comprising:

• program code executable by a computer for causing the computer to receive, at a target base station, a random access request from a user equipment (UE) using a contention- free random access (CFRA) procedure at one or more beams scheduled for CFRA;
• program code executable by the computer for causing the computer to transmit, by the target base station, a random access response to the UE identifying a delay until an uplink transmission opportunity;
• program code executable by the computer for causing the computer to detect, by the target base station, a contention-based random access (CBRA) request from the UE prior to the uplink transmission opportunity;
• and
• program code executable by the computer for causing the computer to reduce, by the target base station, the delay for a next uplink transmission opportunity using CFRA.

A non-transitory computer-readable medium having program code recorded thereon, the program code comprising:

• program code executable by a computer for causing the computer to receive, at a target base station, a handover request associated with a user equipment (UE);
• program code executable by the computer for causing the computer to generate, by the target base station, a handover command including a random access configuration, wherein the random access configuration includes configuration for contention-free random access (CFRA) and contention-based random access (CBRA);
• program code executable by the computer for causing the computer to schedule, by the target base station, one or more beams for CFRA and one or more additional beams for CBRA;
• program code executable by the computer for causing the computer to detect, by the target base station, handover initiation by the UE using the one or more additional beams for CBRA;
• and
• program code executable by the computer for causing the computer to release, by the target base station, schedule of the one or more beams for CFRA.

An apparatus configured for wireless communication, the apparatus comprising:

• at least one processor;
• and
• a memory coupled to the at least one processor,
• wherein the at least one processor is configured:
• to receive, at a user equipment (UE), a random access configuration, wherein the random access configuration includes configuration for contention-free random access (CFRA) and contention-based random access (CBRA);
• to determine, at the UE, a first random access resource, wherein the first random access resource maps to one or more beams from a target base station;
• to determine, by the UE, a beam quality associated with the first random access resource;
• and
• to initiate, by the UE, a random access request using the CBRA when the first random access resource is a contention-free resource, and the beam quality of the first random access resource is below a threshold beam quality.

An apparatus configured for wireless communication, the apparatus comprising:

• at least one processor;
• and
• a memory coupled to the at least one processor,
• wherein the at least one processor is configured:
• to receive, at a user equipment (UE), a random access configuration, wherein the random access configuration includes configuration for contention-free random access (CFRA) and contention-based random access (CBRA);
• to determine, at the UE, a first random access resource, wherein the first random access resource maps to one or more beams from a target base station;
• to initiate, by the UE, a random access request using the CFRA when the first random access resource is a contention-free resource;
• to fail, by the UE, to detect a random access response to the random access request using the CFRA prior to a predetermined period of time after execution of the configuration of the at least one processor to initiate the random access using the CFRA;
• and
• to initiate, by the UE, CBRA at a next contention-based resource, wherein the next contention-based resource maps to one or more additional beams of the target base station.

An apparatus configured for wireless communication, the apparatus comprising:

• at least one processor;
• and
• a memory coupled to the at least one processor,
• wherein the at least one processor is configured:
• to receive, at a user equipment (UE), a random access configuration, wherein the random access configuration includes configuration for contention-free random access (CFRA) and contention-based random access (CBRA);
• to determine, at the UE, a first random access resource, wherein the first random access resource maps to one or more beams from a target base station;
• to initiate, by the UE, a random access request using the CFRA when the first random access resource is a contention-free resource;
• and
• to initiate, by the UE, the random access request using the CBRA when the first random access resource is a contention-based resource.

An apparatus configured for wireless communication, the apparatus comprising:

• at least one processor;
• and
• a memory coupled to the at least one processor,
• wherein the at least one processor is configured:
• to receive, at a target base station, a random access request from a user equipment (UE) using a contention-free random access (CFRA) procedure at one or more beams scheduled for CFRA;
• to transmit, by the target base station, a random access response to the UE identifying a delay until an uplink transmission opportunity;
• to detect, by the target base station, a contention-based random access (CBRA) request from the UE prior to the uplink transmission opportunity;
• and
• to reduce, by the target base station, the delay for a next uplink transmission opportunity using CFRA.

An apparatus configured for wireless communication, the apparatus comprising:

• at least one processor;
• and
• a memory coupled to the at least one processor,
• wherein the at least one processor is configured:
• to receive, at a target base station, a handover request associated with a user equipment (UE);
• to generate, by the target base station, a handover command including a random access configuration, wherein the random access configuration includes configuration for contention-free random access (CFRA) and contention-based random access (CBRA);
• to schedule, by the target base station, one or more beams for CFRA and one or more additional beams for CBRA;
• to detect, by the target base station, handover initiation by the UE using the one or more additional beams for CBRA;
• and
• to release, by the target base station, schedule of the one or more beams for CFRA. NRF NO. QLXX.P1188US