Slot-based persistent allocation for WiMAX systems

This paper proposes a slot-based persistent allocation scheme which allows WiMAX base stations (BSs) allocating resources to VoIP-like traffic in an efficient way. The proposed scheme firstly scans resource slots within the stream of data frames to identify an available resource slot for a persistent resource allocation. To facilitate the scanning process, the base station maintains a tree structure for each resource slot, where the tree structure contains several nodes; each of the nodes represents a certain time and periodicity of an allocation. Furthermore, two resource reallocation methods, tree swapping and tree rearrangement, are proposed to maintain the high utilization of the resource slot. Simulation results show that the proposed scheme outperforms the current WiMAX persistent allocation scheme in terms of control message overheads, feedback channel overheads, and scheduling latency.