Interworking architecture between 3GPP IMS, Mobile IP and WiMAX in OPNET

This article represents an interworking architecture model built by OPNET Modeler for intersystem handover between Worldwide Interoperability for Microwave Access (WiMAX), 3GPP IMS-Universal Mobile Telecommunications System (UMTS) and Mobile IP-General Packet Radio Service (GPRS). The interworking model implements IP Multimedia Subsystem (IMS) as a common platform at the application layer for session continuity and Mobile IP at the network layer for maintaining Internet Protocol (IP) mobility. A mobile device with three interfaces and having intelligence of initiating intersystem handover was designed which is capable of maintaining radio links simultaneously with the three access technologies mentioned above. The paper ends with some suggestions of further possible enhancements of the interworking architecture by OPNET Modeller.