DRR adaptive quantum scheduling algorithm for WiMAX multihop relay networks

IEEE 802.16j networks provide considerable improvements related to previous WiMAX specifications in terms of increased coverage area, deployment cost reduction and overall system throughput increase using Relay Stations (RSs). Its main purpose is to meet demands for wireless broadband access in remote areas or require large signal coverage at reduced cost. Efficient resource allocation is a challenge to be faced in IEEE 802.16 standard and requires total commitment of several mechanisms, including the scheduling algorithm. A good part of proposed scheduling rules developed for IEEE 802.16j networks disregards an optimal use of basic resources available. In this work we propose the application of a Deficit Round Robin (DRR) scheduling algorithm with adaptive quantum, operating jointly with a queue management scheme and congestion control in RS output buffer. The simulation results demonstrate a good performance for Unsolicited Grant Service (UGS) and Real-Time Polling Service (rtPS) traffic classes compared to a conventional DRR scheduling algorithm without queue management.