Optimum Fair Bandwidth Allocation Scheme for IEEE 802.16 Mesh Mode with Directional Antenna

The IEEE 802.16 standard is providing support for mesh networks of which two scheduling mechanisms (i.e., centralized scheduling and distributed scheduling) are proposed. Centralized scheduling which builds on a routing tree behaves in a centralized manner and therefore presents more QoS guarantee than distributed scheduling. However, IEEE 802.16 standard doesn´t specify how to schedule traffic in the mesh mode. In this paper, we focus on centralized scheduling and extensively explore it´s spatial reuse potential under the condition of directional antenna. In particular, we propose a scheduling mechanism which is optimum in terms of schedule length, and we introduce a bandwidth scaling algorithm in case the minimum schedule length is larger than the frame length. Simulation results show that our proposed scaling mechanism outperforms ordinary breadth first traversal.