A novel SIP based procedure for congestion aware handover in heterogeneous networks

One of the next steps in the current rapid evolution of wireless technologies will be that operators will need to enable users to use communication' services independently of access technologies, so they will have to support seamless handovers in heterogeneous networks. In this paper we present a novel SIP based procedure for congestion aware handover in heterogeneous networks. With newly defined SIP messages the handover decision is based not only on signal strength, but also on target network status. Using the SIP protocol, this approach is completely independent of access technology and the underlying protocol used, and thus can be easily deployed in operator's environments. The proposed procedure was evaluated with a purpose-built simulation model. The results show that, using the proposed procedure, the QoE of VoIP users can be maintained during session by eliminating handovers to target network, which could cause degradation of service in the target network and by triggering handovers to another network, when there could come to degradation of service in the current network. (C) 2010 Elsevier B.V. All rights reserved.