US 12,289,769 B2
Back-off for 2-step RA procedure
Henrik Enbuske, Stockholm (SE); Jan Christoffersson, Luleå (SE); and Mats Folke, Vällingby (SE)
Assigned to Telefonaktiebolaget LM Ericsson (publ), Stockholm (SE)
Appl. No. 17/608,019
Filed by Telefonaktiebolaget LM Ericsson (publ), Stockholm (SE)
PCT Filed May 1, 2020, PCT No. PCT/IB2020/054144
§ 371(c)(1), (2) Date Nov. 1, 2021,
PCT Pub. No. WO2020/222191, PCT Pub. Date Nov. 5, 2020.
Claims priority of provisional application 62/842,285, filed on May 2, 2019.
Prior Publication US 2022/0369373 A1, Nov. 17, 2022
Int. Cl. H04W 74/08 (2024.01); H04W 74/0833 (2024.01)
CPC H04W 74/0833 (2013.01) 26 Claims
OG exemplary drawing
 
1. A method, in a wireless device configured to perform a 2-step random access (RA) procedure, the method comprising:
transmitting a message according to the 2-step RA procedure, the message comprising a first random access preamble;
receiving, during a random access response window following the transmitting of the message, a Medium Access Control (MAC) subheader; and
using one or more bits or fields included in the received MAC subheader, selecting from among the following, for subsequent action:
backing off, according to a back-off parameter, for a subsequent RA attempt according to the 2-step RA procedure, wherein backing off comprises waiting for a random time between zero and a time indicated by the back-off parameter before a new transmission of a random access preamble; and
falling back to a 4-step RA procedure by transmitting a new random access preamble; and
falling back to a 4-step RA procedure after backing off according to a back-off parameter, by transmitting a new random access preamble after the back-off.