Expected path duration maximized routing algorithm in CR-VANETs

In Cognitive-Radio (CR) enabled Vehicular Ad-Hoc NETworks (CR-VANETs), high mobility of vehicles and dynamically varying spectrum occupation statuses frequently cause the established routes broken. To deal with the increasing mobility and dynamics of accessible spectrum, we propose an expected path-duration maximized routing (EPDM-R) algorithm in CR-VANETs. Specifically, we study the scenario of cognitive radio enabled vehicles communications freeway mobility model. the vehicles, as secondary users (SUs), can access the licensed channels of primary users (PUs) when these channels are not occupied, where the behaviors of PUs follow the call-based model. In the EPDM-R algorithm, we firstly calculate the expected link-duration for each link. Then, the max-bottleneck algorithm is used to solve for the route achieving the longest expected path-duration. Theoretic analysis prove the optimality of our proposed EPDM-R algorithm in terms of maximizing EPD. Simulation results demonstrate that our proposed algorithm has larger average path-duration than the Dijkstra based scheme and the scheme that does not take the PUs' behaviors into consideration.