Enabling vehicular mobility in city-wide IEEE 802.11 networks through predictive handovers

The increasing number of IEEE 802.11 networks deployed worldwide gives mobile users the possibility of experiencing high-speed wireless access on the move. Moreover, the high density of these deployments in urban areas make IEEE 802.11 a suitable access technology for moving vehicles. However, in order to provide a seamless access to vehicles, the transition between Access Points (APs) must be quick and reliable. The main bottleneck of existing handover mechanisms is the long AP scanning process, which only provides a snapshot of the available networks at a given location, impacting the handover decision on moving vehicles. To overcome this limitation, we propose coper, a context-based predictive handover mechanism that considers vehicle's trajectory, road topology, and network deployment information to decide the best handover location and candidate access points. We validate with real experiments in a city-wide 802.11 network and show that coper can provide better average signal strength, data rate, and connected time than other existing handover approaches.