Vertical Handoff Strategy on Achieving Throughput in Vehicular Heterogeneous Network

Vehicular communication, as a novel fundamental platform for providing wireless access, is drawing more and more attentions in recent years. IEEE 802.11p is a main radio access technology which supports communication for high mobility terminals. Due to the small coverage, road side unit (RSU) is usually deployed coupling with cellular network to achieve seamless mobility. In cellular/802.11p heterogeneous network, vehicular communication has the characteristics of short span of time associate with wireless local area network (WLAN). Besides that, the media access control (MAC) scheme of WLAN leads to the issue that network throughput decreases dramatically with the increasing of user quantity. Therefore, vehicular mobility and network load should be seriously taken into account with respect to the feasibility of vertical handoff decision. In response to these compelling problems, we propose an analytical model for estimating the average achievable individual throughput, and further the theoretically optimal handoff threshold. Simulation results are demonstrated under different conditions in terms of vehicle´s velocity and user quantity. The work in this paper can be a reference for the issue of whether and when to execute handoff procedure in vehicular heterogeneous network.