US 12,356,467 B2
Random access method and device and communication system
Yang Lu, Beijing (CN)
Assigned to FUJITSU LIMITED, Kawasaki (JP)
Filed by FUJITSU LIMITED, Kawasaki (JP)
Filed on Oct. 27, 2021, as Appl. No. 17/511,637.
Application 17/511,637 is a continuation of application No. PCT/CN2019/085332, filed on Apr. 30, 2019.
Prior Publication US 2022/0053576 A1, Feb. 17, 2022
Int. Cl. H04W 74/0833 (2024.01); H04L 5/00 (2006.01); H04W 56/00 (2009.01); H04W 74/08 (2009.01)
CPC H04W 74/0841 (2013.01) [H04L 5/0051 (2013.01); H04W 56/001 (2013.01); H04W 74/0866 (2013.01)] 13 Claims
OG exemplary drawing
 
1. A random access device, applicable to a terminal equipment, the device comprising:
first controlling circuitry configured to control the terminal equipment to initiate a two-step random access procedure; and
second controlling circuitry configured to control the terminal equipment to initiate a four-step random access procedure when a number of times of two-step random access preamble(s) transmission reaches a first maximum threshold and no random access response is received in a random access response reception window after a first message (MsgA) of the two-step random access procedure is transmitted,
wherein initiating the four-step random access procedure at least comprises initialization of:
a power ramping step factor of the four-step random access procedure; and
a maximum number of times of transmission of preambles of the four-step random access procedure,
wherein the initiating the four-step random access procedure comprises:
measuring synchronization reference signal (SS-RS) received power of synchronization signal/physical broadcast channel blocks (SS/PBCH Blocks, SSBs) transmitted by a network device, and selecting a synchronization signal/physical broadcast channel block (SS/PBCH block, SSB) used in the four-step random access procedure; and
determining a preamble of the four-step random access procedure to be transmitted according to the selected SSB.