Since Wireless Access in Vehicular Environment (WAVE) is a draft amendment to the IEEE 802.11 standard, the integration of WAVE (IEEE 802.11p) and Wireless Metropolitan Area Network (IEEE 802.16) becomes a concerned issue to mobile network users. During the roaming between the two heterogeneous wireless networks, the quality of multimedia services for users depends heavily on seamless handover, which should be provided by the middleware between IP and MAC protocol stack. For this reason, we design the heterogeneous handoff of WAVE-WiMAX by seamless handoff scheme from buffer prediction of IEEE 802.21. IEEE 802.21 is designed to provide the basic platform for seamless heterogeneous handoff. Due to the integration function provided by IEEE 802.21, users are able to use the original services between heterogeneous wireless networks. In this paper, a dynamically adjusted buffer component with an algorithm to predict the buffer size is proposed to enhance the functionality of IEEE 802.21. The services and communication flows among service specific layer, buffer and IEEE 802.21 Media Independent Handover (MIH) function are described and analyzed. According to the analysis of the connection process and simulation, buffer prediction and pre-allocation indeed can reduce the influence of handover between heterogeneous wireless networks.
Journal Information Science and Engineering 26(3), pp.851-866