	US 12,155,696 B2
	Method and apparatus for internet protocol multimedia subsystem (IMS) signaling for non-service attempt
Sangmin Park, Seoul (KR); Sungduck Chun, Seoul (KR); Laeyoung Kim, Seoul (KR); and Myungjune Youn, Seoul (KR)
Assigned to LG ELECTRONICS INC., Seoul (KR)
Appl. No. 17/628,851
Filed by LG ELECTRONICS INC., Seoul (KR)
PCT Filed Aug. 4, 2020, PCT No. PCT/KR2020/010267 § 371(c)(1), (2) Date Jan. 20, 2022, PCT Pub. No. WO2021/025430, PCT Pub. Date Feb. 11, 2021.
Claims priority of application No. 10-2019-0096050 (KR), filed on Aug. 7, 2019.
Prior Publication US 2022/0263874 A1, Aug. 18, 2022
Int. Cl. H04L 65/1016 (2022.01); H04L 65/1073 (2022.01); H04W 48/16 (2009.01); H04W 80/10 (2009.01)

CPC H04L 65/1016 (2013.01) [H04L 65/1073 (2013.01); H04W 48/16 (2013.01); H04W 80/10 (2013.01)]

16 Claims

1. A method for a terminal to perform communication related to Internet Protocol Multimedia Subsystem (IMS), comprising:

transmitting, by an IMS layer of the terminal, a first request message, to a Non Access Stratum (NAS) layer of the terminal,

wherein the first request message includes information related to IMS signaling for a non-service attempt and information related to a first access category among a plurality of access categories related to an IMS service,

wherein the plurality of the access categories are access categories 4, 5, and 6, and

wherein the IMS signaling for the non-service attempt is signaling that does not request the IMS service;

transmitting, by the NAS layer of the terminal, a second request message including information related to the first access category to a Radio Resource Control (RRC) layer of the terminal, based on the information related to IMS signaling for the non-service attempt;

receiving, by the NAS layer of the terminal, a response message indicating that the second request message is barred from the RRC layer of the terminal; and

based on that the second request message is barred, transmitting, by the NAS layer of the terminal, a third request message including information related to a second access category, which is different from the first access category, among the plurality of the access categories, based on the information related to IMS signaling for the non-service attempt.