A handover algorithm support for multimedia service provision in heterogeneous packet-oriented mobile environments

Third generation mobile communication systems will provide multimedia services across heterogeneous mobile networks and will need to support seamless mobility in a more flexible and intelligent manner than previous generations. As the main components under the third generation mobile communications system, UMTS and GPRS (an intermediate second generation GSM evolution) will support packet-switched services. An interesting future scenario could be the handover between GPRS and UMTS, providing seamless service connectivity to the user. In such an environment, existing handover algorithms may not meet the requirements of providing seamless handover. A graceful adaptation to quality of service (QoS) variations due to network heterogeneity is deemed necessary. In this paper, we consider the problem of providing seamless or nearly seamless handover between GPRS and UMTS. Assuming a mobile controlled handover algorithm, the handover connection management functional model, consisting of two main components: the handover control entities and the QoS control entities, is then derived. The network architecture is then identified for the mobile scenario under investigation. The functional model is then mapped onto the network architecture to provide the functional architecture from which the handover signalling protocol and the information flows of the chosen handover algorithm are derived