On the evaluation of make-before-break handovers in urban WiFi networks for moving vehicles

Due to the increasing deployment of city-wide IEEE 802.11 networks for nomadic Internet access, there is a great potential for users wanting to access the network while being on the move. However, due to the limited coverage range of single access points in these networks, handovers between them need to be carefully managed. This issue becomes critical if we consider vehicular users, where the high speed and mobility pattern greatly affect the connectivity performance. In this paper, we evaluate the performance of different handover approaches in a real commercial deployment under vehicular mobility constraints. In particular, we consider using a second wireless interface in order to achieve make-before-break handovers. Additionally, we identify some open issues that constrain IEEE 802.11 commercial deployments in providing completely seamless connectivity for moving vehicles.