A Variable-Length Burst Scheduling Algorithm (VLBS) for Downlink Traffic in IEEE 802.16m OFDMA Systems
In IEEE 802.16m networks, each frame is divided into eight Advanced Air Interface (AAI) sub-frames, composed of Logical Resource Units (LRUs). According to stations' requirements, Advanced Base Stations (ABSs) allocate bursts constructed by contiguous LRUs to stations. If ABSs can not efficiently schedule and allocate bursts, bandwidth resource will be wasted in or among bursts. Such these problems are called internal fragmentation and external fragmentation in this paper. In this paper, this paper formulates a downlink burst allocation problem, considering both Internal Fragmentation (IF) and External Fragmentation (EF), and then proposes a variable-length burst scheduling algorithm, called VLBS, to determine the position and the number of required LRUs of each burst in the DownLink (DL) AAI sub-frame, subject to minimizing the bandwidth wastage.