A performance analysis of context transfer protocols for QoS enabled Internet services

In nowadays wireless networks, mobile users frequently access Internet services that are often based on information concerning the application context and service status. In presence of mobility, the procedure of service handover, may require a restart of the ongoing service, if the necessary context information is not properly transferred to the new point of access. Context transfer procedures introduce additional overheads to handovers possibly affecting the quality of service perceived by mobile users and making handovers very critical. In this paper the need for efficient protocols for transferring service context and profile related information is pointed out with reference to many mobile internet services, and the possible scenarios are differentiated on the basis of the handover triggering mechanisms. A performance model to compare these mechanisms, when context transfer protocols run on top of IPv6 with fast handover, is proposed. Numerical results point out the necessity to adapt the triggering mechanism to the size of the context data.