QUALCOMM Incorporated
Timing indication for a two-step random access channel procedure

Abstract:

Methods, systems, and devices for a two-step random access channel (RACH) procedure are described that may enable a user equipment (UE) and a base station to perform a two-step RACH procedure and begin communications using an accurate timing advance (TA). The UE may send a first RACH message of the two-step RACH procedure to the base station. The base station may determine an accurate TA based on the contents of the first RACH message. The base station may prepare a downlink control message and a corresponding second RACH message to send to the UE. The base station may include scheduling information for the second message and an indication of the TA in the downlink control message. The base station may identify one or more data fields in bits within the downlink control message reserved for information other than the TA and replace the bits with the TA indication.