Adaptive Competitive On－Line Cost－based Routing Algorithm for IEEE 802.16j WiMAX Mobile Multihop Relay Networks

Based on the IEEE 802.16e standard, WiMAX proposes a Mobile Multihop Relay (MMR) approach defined in the IEEE 802.16j standard to extend the service area of Base Stations (BSs), and then improves the quality of received signal strength. Clearly, WiMAX MMR achieves a low-cost coverage-extension solution for the existing WiMAX network WiMAX MMR supports three types of Relay Stations (RS): Fixed RS, Nomadic RS and Mobile RS. Each type of RS is with different features on mobility and relay range. Since the relay-based WiMAX network includes different types of RSs, how to efficiently construct the relay-based WiMAX and how to determine an optimal routing path between a Mobile Station (MS) and the MR-BS are two important Issues that should be addressed. This paper thus proposes an IEEE 802.16j-conformed relay-based adaptive cost-based routing approach, in which a multihop optimal path is selected in terms of link bandwidth, path length and channel condition. Numerical results demonstrate that the proposed routing approach significantly outperforms other approaches in fractional reward loss, network utilization and average end-to-end path delay.