Efficient handoff based on link quality prediction for video streaming in urban transport systems

The continuously increasing interest in developing efficient vehicle-roadside communication networks to provide on-board connectivity has recently brought to the definition of several solutions based on different wireless technologies. Among them, wireless local area network-based solutions emerged as an attracting alternative to guarantee high-quality connectivity enabling services, like video streaming, that require stringent quality of service guarantees. In this work, we propose a handoff procedure based on a forecasting model of the link quality for mobile routers operating in vehicle-roadside wireless local area network-based networks. First, a preliminary set of experiments is performed in a realistic environment to study the behavior of the wireless channel when mobility in urban environment is considered. Then, considering the hands-on experience gained from the initial set of experiments, a novel handoff procedure is designed, which exploits a forecasting technique to predict link channel quality. The proposed procedure is then exploited in a cross-layer manner to proactively reduce the number of transmitted layers during handoff in the case of real-time video traffic based on H.264/SVC encoding. The proposal is assessed by means of simulation and compared with existing solutions. Results demonstrate that our proposal guarantees performance comparable with other algorithms. The advantage of predicting the handoff point is demonstrated by means of simulations employing a realistic video streaming traffic model, showing how the quality of experience perceived by end-users can be improved through the adaptation of the traffic load. Copyright © 2016 John Wiley & Sons, Ltd.