Apple Inc.

Sergey Sosnin

Seunghee Han

Gang Xiong

Yushu Zhang

Hwan-Joon Kwon

Yongjun Kwak

Sergey Panteleev

Alexey Khoryaev

Yujian Zhang

Seau S Lim

This disclosure describes improving a 4-step RACH procedure by using a 2-step RACH procedure. A UE transmits a PRACH preamble and associated MsgA physical uplink shared channel (PUSCH) on a configured time and frequency resource. After successful detection of the PRACH preamble, and decoding of the MsgA PUSCH, the gNB transmits MsgB in the second step. Generally, a mapping is used between the PRACH preamble and the PUSCH resource unit for 2-step RACH. This disclosure describes the mapping for 2-step RACH.

Mapping between PRACH preambles and PUSCH resource units for 2-step RACH

Some embodiments of this disclosure include apparatuses and methods for a fallback procedure for a 2-step random access channel (RACH) procedure for data transmission in a wireless communication system where the apparatuses and methods include at least generating, by a user equipment (UE), a first signal that includes a first message (MsgA) for a 2-step random access channel (RACH) procedure, transmitting, by the UE, the first signal to a next generation NodeB (gNB), determining, by the UE, whether a 4-step RACH procedure is to be used to further transmit the first signal including the MsgA, and further transmitting, by the UE, the first signal to the gNB using the 4 step RACH procedure based on determining that the 4-step RACH procedure should be used.

Fallback procedure for 2-step RACH

A method for handling a Message A physical uplink shared channel (PUSCH) transmission in a random access channel (RACH) procedure for use in fifth generation new radio (5G NR) wireless communication system includes determining that the Message A PUSCH transmission in a first step of a two-step RACH procedure overlaps with at least one other uplink physical channel transmission and transmitting at least one of the Message A PUSCH transmission or the at least one other uplink physical channel transmission in accordance with a priority rule.

Collision handling of physical uplink shared channel transmissions in a two-step random access channel procedure

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Cupertino, CA, United States of America

Sergey Sosnin