Reallocation of serving proxy function in IMS

摘要

The invention relates to a method of changing allocation of Serving-Call Session Control Functions (S-CSCFs) to a user of an IMS network. The user is being provided with services via a first S-CSCF allocated to the user. The method includes implementing a re-allocation instruction at the first S-CSCF. The reallocation instruction includes criteria for de-allocation of the user from the first S-CSCF. The S-CSCF determines if the criteria are met; and if the criteria are met, de-allocates the user.

主权项

1. A method of changing allocation of serving Call Session Control Functions (S-CSCFs) to a user equipment (UE) of an IP Multimedia Subsystem (IMS) network, wherein the UE is being provided with services via a first S-CSCF allocated to the UE, the method comprising:
receiving at the first S-CSCF criteria for de-allocating the first S-CSCF from the UE, the received criteria specifying one or more conditions that are required to be met prior to de-allocating the first S-CSCF from the UE; receiving at the first S-CSCF a de-allocation instruction; in response to receipt of the deallocation instruction, the first S-CSCF determining if the one or more conditions specified in the criteria are met; and if the one or more conditions specified in the criteria are met, the first S-CSCF de-allocating itself from the UE, the one or more conditions including:
(i) a no-active-session deregistration or de-assignment criteria, wherein the user is to be de-registered or the first S-CSCF de-assigned if the user is not engaged in an active IMS session,(ii) session specific deregistration or deassignment criteria, wherein the UE is not to be deregistered or the first S-CSCF deassigned if the UE is engaged in an active IMS session, and(iii) deregistration criteria that is dependent on a status of a communication session of the UE, and wherein the received criteria for de-allocating the first S-CSCF is included in an instruction received from a home subscriber server (HSS) for re-allocating the UE for the first S-CSCF.