design of a fast handoff scheme for vehicular mesh networks with directional antennas
Vehicular Mesh Networks (VMNs) are a special kind of Wireless Mesh Networks (WMNs). In VMNs, the mesh clients are vehicles which are equipped with wireless antennas for wireless communication. In VMNs, wireless terminals can transmit data frames among each other through wireless connections using IEEE 802.11 standards. However, it is challenging to achieve smooth roaming in vehicular mesh networks, because the transmission range of wireless antennas is limited and the vehicle nodes have high mobility. In this paper, we propose a Hidden Markov Model (HMM) based mobility prediction solution to reduce the MAC layer handoff latency for VMNs which use directional antennas to provide spatial separation. For the vehicle node which is going to trigger the handoff process, before it starts the handoff, the access router can predict the next probable access router based on the current signal quality of the wireless communication and the antenna which is used to provide the wireless connection for the vehicle node. When the handoff process is triggered, instead of scanning all the available access routers during handoff, the vehicle node can directly connect with potential access router using the prediction. As a result, the handoff latency in MAC layer can be reduced.
handoff vehicular mesh networks hidden markov model