Techniques for configuring random access transmissions

A method for wireless communications at a user equipment (UE), comprising:

• receiving a control message from a network device, the control message specifying for the UE to use a first random access procedure from a plurality of random access procedures to configure a random access message, the plurality of random access procedures comprising a two-step random access procedure and a four-step random access procedure;
• identifying a listen before talk (LBT) procedure based at least in part on the first random access procedure specified in the control message and a procedure for which the first random access procedure is used, the procedure comprising a beam failure recovery, a handover completion, a system information, or a combination thereof;
• configuring the LBT procedure to be performed prior to transmitting the random access message;
• and
• establishing a connection with the network device by performing the first random access procedure.

An apparatus for wireless communications at a user equipment (UE), comprising:

• a processor,
• memory in electronic communication with the processor;
• and
• instructions stored in the memory and executable by the processor to cause the apparatus to:
• receive a random access configuration message over a wireless channel, the random access configuration message indicating a channel metric and a threshold, wherein the random access configuration message comprises a timing advance;
• select a reference signal based at least in part on a received configuration message and based at least in part on at least one of the channel metric or the threshold;
• determine the channel metric based at least in part on receiving the random access configuration message, wherein determining the channel metric comprises receiving a measurement of the selected reference signal;
• select a first random access procedure from a plurality of random access procedures based at least in part on the channel metric and the threshold indicated in the random access configuration message, wherein selecting the first random access procedure comprises selecting a two-step random access procedure as the first random access procedure based at least in part on the timing advance;
• and
• establish a connection with a network device by performing the first random access procedure.

An apparatus for wireless communications at a user equipment (UE), comprising:

• a processor,
• memory in electronic communication with the processor;
• and
• instructions stored in the memory and executable by the processor to cause the apparatus to:
• receive a control message from a network device, the control message specifying for the UE to use a first random access procedure from a plurality of random access procedures to configure a random access message, the plurality of random access procedures comprising a two-step random access procedure and a four-step random access procedure;
• identify a listen before talk (LBT) procedure based at least in part on the first random access procedure specified in the control message and a procedure for which the first random access procedure is used, the procedure comprising a beam failure recovery, a handover completion, a system information, or a combination thereof;
• configure the LBT procedure to be performed prior to transmitting the random access message;
• and
• establish a connection with the network device by performing the first random access procedure.