Adaptive Connectivity Aware Routing Protocol for Wireless Vehicular Networks

Multi-hop vehicle-to-vehicle communication is useful for supporting many vehicular applications that provide drivers with safety and convenience. D veloping multi-hop communication in vehicular ad hoc networks (VANETs) is a challenging probl em due to the rapidly changing topology and frequent network disconnections, which cause failure or inefficiency in traditional ad hoc routing protocols. We propose an adaptive connectivi ty aware routing (ACAR) protocol that addresses these problems by adaptively selecting a n optimal route with the best network connectivity-quality (CQ) based on statistical and real-t ime density data that are gathered through an on-the-fly density collection process. The CQ metric mode ls th joint probability that a network is connected and a packet is successfully delivered in this n etwork. The protocol consists of two parts: 1) select an optimal route, consisting of road segmen ts, with the best CQ, and 2) in each road segment of the chosen route, select the most efficient multihop path that will improve the delivery ratio and throughput. The optimal route is selected usin g our connectivity-quality metric that takes into account vehicles densities and traffic light peri ods to estimate the probability of network connectivity and data delivery ratio for transmitting pack ets. Our simulation results show that the proposed ACAR protocol outperforms existing VANETs routin g protocols, e.g. the delivery ratio of ACAR is 19% higher than VADD, the second best protocol. ACAR is built upon geographic routing which requires every v ehicle to broadcast its location information to its neighbors, and this process will comprom ise user’s location privacy. To address this issue, we proposed a dummy-based location privacy prot ecti n (DBLPP) protocol in VANETs. In DBLPP, routing decision is made based upon the dummy dista nce to destination (DOD), instead of user’s true location. In this scheme, a user’s true locati n and identification information are preserved, so the user’s location privacy is protected. Sim ulation results show that the DBLPP provides similar network performances as other routing pro toc ls, and achieves a higher level of