Optimal Relay Selection in IEEE 802.16j Multihop Relay Vehicular Networks

This paper examines the IEEE 802.16j multihop relay (MR) technology that improves vehicle-to-infrastructure communications. We study the selection of optimal relay station (RS) for a vehicular subscriber station (SS) that maximizes the end-to-end capacity, assuming that the locations of vehicular SSs are known. By incorporating a highway mobility model, the problem can be formulated into a nonlinear optimization problem and solved for the optimal locations of RSs that guarantee maximal end-to-end capacities to SSs. Numerical results from a case study show that the selection of the corresponding optimal RS increases the expected end-to-end capacity for individual SSs by 50%, as compared with the method without using relays.