Transmission Delay Reduction in IMS by Re-registration Procedure Modification

As a result of the evolution of computer and networking technologies, the Third Generation Partnership Project (3GPP) has proposed the IP Multimedia Subsystem (IMS) as a key element in Next Generation Networks (NGN) that supports multimedia services in the packet switched domain. To use IMS services, users should register in IMS network and to have their information be registered in IMS Databases. When transport media is mobile and user handover in the access network, the re-registeration procedure is needed. This is similar to initial register procedure and leads to excessive transmission delay. In this paper a solution is introduced to reduce the re-registration delay by reducing the number of required contacts with IMS Databases. We have compared re-registration time in our proposed scheme with the standard scheme in OPNET modeler 10.5. Simulation results have confirmed better performance for the proposed scheme.