US 12,262,421 B2
Radio terminal, radio access network node, and method therefor
Hisashi Futaki, Tokyo (JP)
Assigned to NEC CORPORATION, Tokyo (JP)
Filed by NEC Corporation, Tokyo (JP)
Filed on Apr. 3, 2024, as Appl. No. 18/625,422.
Application 18/625,422 is a continuation of application No. 17/284,904, granted, now 11,997,720, previously published as PCT/JP2019/032470, filed on Aug. 20, 2019.
Claims priority of application No. 2018-202276 (JP), filed on Oct. 26, 2018.
Prior Publication US 2024/0276556 A1, Aug. 15, 2024
This patent is subject to a terminal disclaimer.
Int. Cl. H04W 74/0833 (2024.01)
CPC H04W 74/0833 (2013.01) 19 Claims
OG exemplary drawing
 
1. A method performed by a User Equipment (UE), the method comprising:
receiving, from a communication apparatus, information indicating a maximum number of preamble transmissions of a 2-step Contention Based Random Access (CBRA);
transmitting a first message of the 2-step CBRA to the communication apparatus;
receiving a second message of the 2-step CBRA from the communication apparatus,
wherein the second message includes:
a Medium Access Control (MAC) subheader associated with a fallback, and
an uplink grant indicating an uplink resource used for transmission of a third message of a 4-step CBRA;
transmitting, to the communication apparatus, the third message of the 4-step CBRA based on the uplink grant in a case where the UE receives the second message;
falling back to the 4-step CBRA after a number of preamble transmissions of the 2-step CBRA reaches the maximum number of preamble transmissions of the 2-step CBRA; and
keeping a counter for counting the number of preamble transmissions in a case of the falling back to the 4-step CBRA.