CoRoute: a new cognitive anypath vehicular routing protocol

Vehicular communications promise to bring us safer driving and better traffic control. Dedicated short range communications and IEEE 802.11p are now well established standards for vehicular communications. Channels for those systems, however, are of limited capacity and are dedicated to safety applications. Thus, they are not sufficient to support the broad range of services envisioned in VANETs. It is anticipated that vehicles will utilize Wi-Fi (802.11 a/b/g) to acquire more capacity. Unfortunately, the Wi-Fi channels in urban areas are already quite heavily subscribed by residential customers. To evade the residential load, in this paper, we propose CoVanet, a cognitive vehicular ad hoc network architecture that allows vehicle radios to access the Wi-Fi channels 'opportunistically', finding least loaded channels. In CoVanet, network topology and channel environment change frequently because of high node mobility. The main contribution of this work is a cognitive ad hoc vehicular routing protocol (CoRoute). CoRoute is a hybrid that utilizes both geographical location and sensed channel information to establish stable, minimum delay routes to the destination. Simulation results show that CoRoute is robust to mobility and to external interference and improves packet delivery ratio on average by 70% with respect to routing without cognitive radios. Copyright (C) 2011 John Wiley & Sons, Ltd.