Apple Inc.
Framework for Two-Step Random Access Channel Procedure in Wireless Communications

Abstract:

A device may wirelessly transmit a physical RACH, and a first message on a physical uplink shared channel (PUSCH), in a first step of a 2-step random access channel (RACH) procedure. The device may receive a second message on a physical downlink shared channel in response to successful detection of the first message, in a second step of the 2-step RACH procedure. When detection of the first message is unsuccessful, the device may be instructed to fall back to a 4-step RACH procedure. The device may be configured with one or more first message transmit opportunities (PO), one of which may include one or more PUSCH resource units (PRUs). Some of the communication parameters of the device may be configured to be common for each PO, while other communication parameters may be configured per PRU. Respective new Radio Network Temporary ID values may be defined for the first message and second message.