Data downloading in relay assisted mobile vehicles

Traditionally, every mobile station (MS) riding in the mobile vehicle uses conventional connection to the base station (BS). However, in 802.16j mobile multihop relay (MMR) networks, one of the studied usage model is ldquocoverage on mobile vehiclerdquo. Therein, a relay station (RS) is mounted on a vehicle. The RS provides service to MSs riding on the vehicle by relaying their data to the mobile multihop relay base station (MMR-BS). This brings several benefits compared to the situation where every MS would individually connect to the MMR-BS, including power savings and better channel condition. In this work, we consider a scenario where user is considered sitting in the vehicle and downloading data via relay station which is mounted on top the vehicle. The downloading typically uses the RS mounted on the vehicle but direct communication to the MMR-BS is also allowed. We characterize both the access links (MS-RS, MS-BS) and the relay link (RS-BS) by throughput-distance relationship models. The decision whether to use RS or to communicate directly with the MMR-BS is decided based on comparing the combined throughput distance model. (MS-RS-BS) with the throughput obtained using direct access link. Numerical results are provided using a two-turn mobility model. The results show that mobility and velocity of mobile vehicle have a great impact on the performance of mobile vehicle relay assisted network.