Message 2 of a two-step random access procedure and coexistence with four-step random access procedure

An apparatus for wireless communication at a network entity, comprising:

• at least one processor;
• at least one memory coupled with the at least one processor;
• and
• instructions stored in the at least one memory and executable by the at least one processor to cause the network entity to:
• receive an uplink request message from a user equipment (UE), wherein the uplink request message is a first message of a two-step random access channel (RACH) procedure in accordance with the uplink request message comprising a random access preamble and a payload;
• transmit a physical downlink control channel transmission comprising a cyclic redundancy check scrambled by a group random access radio network temporary identifier and an indication of first resources of a broadcast or multicast physical downlink shared channel configured to provide downlink responses for multiple UEs multiplexed at a media access control layer, the downlink responses comprising a downlink response intended for the UE;
• transmitting, via the broadcast or multicast physical downlink shared channel, the downlink response intended for the UE, the downlink response being a second message of the two-step RACH procedure, wherein the downlink response comprises an uplink grant;
• and
• receiving, from the UE, a transmission via second resources indicated in the uplink grant.

A method for wireless communication by a user equipment (UE), comprising:

• selecting to use a two-step random access channel (RACH) procedure, the two-step RACH procedure including an uplink request message and a downlink response;
• transmitting, as a first message of the two-step RACH procedure, the uplink request message to a network entity;
• receiving, from the network entity, a physical downlink control channel transmission comprising a cyclic redundancy check scrambled by a group random access radio network temporary identifier and an indication of first resources of a broadcast or multicast physical downlink shared channel configured to provide downlink responses for multiple UEs multiplexed at a media access control layer, the downlink responses comprising the downlink response intended for the UE;
• receiving, via the broadcast or multicast physical downlink shared channel, the downlink response intended for the UE, the downlink response being a second message of the two-step RACH procedure, wherein the downlink response comprises an uplink grant;
• and
• transmitting via second resources indicated in the uplink grant.