Random access channel (RACH) timing adjustment

A method for wireless communication, comprising:

• receiving a first message of a random access channel (RACH) procedure, the first message comprising a RACH preamble;
• transmitting a second message of the RACH procedure, the second message comprising random access response (RAR) in response to the RACH preamble;
• receiving a third message of the RACH procedure in response to the RAR, wherein the third message comprises a plurality of reference signals (RSs) that are received using a plurality of receive beams;
• determining a plurality of timing advance (TA) parameters, each of the plurality of TA parameters determined for one of the plurality of receive beams;
• transmitting a fourth message of the RACH procedure in response to the third message, wherein the fourth message comprises the plurality of TA parameters, wherein the plurality of TA parameters are included in the same fourth message;
• and
• communicating one or more messages based on at least one of the plurality of TA parameters.

A method for wireless communication, comprising:

• transmitting a first message of a random access channel (RACH) procedure, the first message comprising a RACH preamble;
• receiving a second message of the RACH procedure, the second message comprising random access response (RAR) in response to the RACH preamble;
• transmitting a third message of the RACH procedure in response to the RAR, wherein the third message comprises a plurality of reference signals that are transmitted using a plurality of transmit beams;
• receiving a fourth message of the RACH procedure in response to the third message, wherein the fourth message comprises an index associated with a beam, wherein the fourth message comprises a plurality of TA parameters each determined for one of the plurality of transmit beams, wherein the plurality of TA parameters are included in the same fourth message;
• and
• communicating one or more messages based on the index.

A method for wireless communication, comprising:

• receiving a first message of a random access channel (RACH) procedure, the first message comprising a RACH preamble;
• transmitting a second message of the RACH procedure, the second message comprising random access response (RAR) in response to the RACH preamble;
• receiving a third message of the RACH procedure in response to the RAR, wherein the third message comprises a plurality of reference signals that are received using a plurality of receive beams;
• transmitting a fourth message of the RACH procedure in response to the third message, wherein the fourth message comprises an index associated with a beam, wherein the fourth message comprises a plurality of TA parameters each determined for one of the plurality of receive beams, wherein the plurality of TA parameters are included in the same fourth message;
• and
• communicating one or more messages based on the index.