Analysis of Signaling Cost for a Roaming User in a Heterogeneous Mobile Data Network

In an all-IP environment of internetworked heterogeneous mobile data networks, ongoing data sessions from roaming users are subjected to frequent vertical handoffs. Under such circumstances, careful consideration must be given for the selection of appropriate vertical handoff mechanisms to ensure seamless service continuity and desired quality of service (QoS) levels. Therefore, efficient methods for evaluating and comparing such techniques are essential. One such evaluation technique is signaling cost analysis. This paper presents an analytical model for evaluating signaling cost of vertical handoffs in a heterogeneous mobile networking environment at the core network level for a roaming user. The numerical analysis and evaluation is based on a framework designed for interworking between Universal Mobile Telecommunications System (UMTS), CDMA2000 technology, and mobile WiMAX (worldwide interoperability for microwave access) networks. Results and analysis illustrate the behavior of the signaling cost metric against session arrival rate, network mobility rate, and the call-to-mobility rate.