A New Distributed Scheduling Algorithm for Bandwidth Allocation in IEEE 802.16 Mesh Networks

Multi-hop WiMAX networks has the potential of easily providing high-speed wireless broadband access to areas with little or no existing wired infrastructure. IEEE 802.16 incorporates the quality of service (QoS) mechanisms at the Media Access Control (MAC) level, but it doesn’t define a specific allocation algorithm. The implementation was left open to the service providers’ diligence. Scheduling in WiMAX became one of the most challenging issues, since it was responsible for distributing available resources of the network among all users. Providing QoS in multi-hop WiMAX networks such as WiMAX mesh or mobile multi-hop relay networks is challenging as multiple packets can collide if they are scheduled at the same time. To warranty the QoS requirements, the 802.16 equipment must run some algorithm to allocate slots for connections. We propose an efficient distributed algorithm for packets scheduling in multi-hop WiMAX mobile networks. It is based on the 802.16e parameters, bandwidth request sizes and QoS requirements. The algorithm ensures a dynamic bandwidth allocation for the 802.16 various service classes. Assuming that the packets arrivals follow a Poisson process we build an algorithm witch calculate the number of time slots required for each packet according to its service class and its length.