Minimize Service Interruptions and Power Consumption in Handoff

In Wireless Access the terminal devices are usually highly mobile vehicles or transportation tools, which handoff much more frequently than those in wireless networks. However, the quality of network services like VoIP and multimedia streaming will be seriously influenced by too frequent handoff or too long handoff latency. Due to this reason traditional handoff mechanisms no longer satisfy the need of vehicular communications. At present, most existing fast handoff mechanisms are based on the signal strength of the APs, which does not suit vehicular communications fully. Generally speaking, the regional traffic in Vehicular Adhoc Networks (VANETs) keep changing and varying. This paper presents the Quality Scan scheme, an efficient pre-scanning method to improve the handoff performance in VANETs. With the attempt to reduce the handoff latency and maintain the load balance among the APs, our proposed scheme regularly collects the loading states of the nodes by the pre-established AP controller (APC), and predicts the network traffic of the next moment. Moreover, Mobile Nodes (MNs) can select the most suitable AP for the best QoS according to the parameters received by passive scanning, while more QoS parameters should participate in cooperation. The simulation result proves that our proposed scheme not only maintains the QoS and the load balance among the nodes, but also further enhances the handoff performance in VANETs.