US 12,452,642 B2
Location-based S-CSCF selection in an IMS network
Xavier Ligeret, Seattle, WA (US)
Assigned to T-Mobile USA, Inc., Bellevue, WA (US)
Filed by T-Mobile USA, Inc., Bellevue, WA (US)
Filed on Aug. 22, 2022, as Appl. No. 17/892,959.
Prior Publication US 2024/0064504 A1, Feb. 22, 2024
Int. Cl. H04W 8/04 (2009.01); H04L 61/4511 (2022.01); H04W 4/029 (2018.01); H04W 60/00 (2009.01)
CPC H04W 8/04 (2013.01) [H04L 61/4511 (2022.05); H04W 4/029 (2018.02); H04W 60/00 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A method implemented on an interrogating call session control function (I-CSCF) server, the method comprising:
receiving a request to register a user equipment (UE) to use an IP multimedia service, the request including geographic information of the UE;
determining, based at least in part on the geographic information, that the UE is located in a first region;
determining, based at least in part on the request, that the UE is previously registered through a different region;
comparing an authorized S-CSCF server associated with the previous registration of the UE with a set of S-CSCF servers located in the first region; and
determining, based on the comparing, that there is no match between the authorized S-CSCF server and the set of S-CSCF servers;
based on determining that there is no match, disregarding the authorized S-CSCF and determining a serving call session control function (S-CSCF) server from the set of S-CSCF servers to provide the IP multimedia service to the UE; and
registering the UE on the S-CSCF server.