Cooperative adaptive partner selection for real-time services in IEEE 802.16j multihop relay networks

IEEE 802.16j is defining standards for Multihop Relay (MR) networks. With many low cost Relay Stations (RSs), a Base Station (BS) can diminish the radio range but extend the coverage by RSs. Besides, frequency can be reused in different RSs. When using real-time services in an 802.16j MR network, fixed bandwidth is allocated to each intermediate hop along the path between the MS and the MR-BS. The MS does not need to request bandwidth for each packet in each hop. Therefore overhead is eliminated and packet latency is reduced. However, if an MS suffers from bad channel and cannot transmit packets to its access RS correctly, all bandwidths allocated from the access RS to the MR-BS along the multihop path are wasted. This will decrease the system performance. In this paper, we propose a Cooperative Adaptive Partner Selection (CAPS) algorithm to select a relaying partner to help the MSs experiencing bad channel condition. Simulation results show that the proposed technique can improve the system performance significantly.