Adaptive Uplink Scheduler for WiMAX Networks

Ensuring Quality of Service (QoS) is challenging in Broadband Wireless Access (BWA) networks as it comes with varied QoS needs and supports diverse service classes. As the scheduling mechanisms are not defined in BWA networks, the service providers can choose their own scheduling mechanisms based on their requirements to schedule packets. The Mobile Stations (MSs) can make scheduling decisions regarding service flows as they are aware of the status of queues. This simplifies the overall scheme and increases effectiveness. In Deficit Weighted Round Robin (DWRR), a queue is not served if the size of the packet at the front of the queue exceeds the available quantum. The queue may include smaller packets that may be delayed service. Improved DWRR (IDWRR) checks for packets with sizes less than the DeficitCounter and sorts the queue and services the smaller packet in the current round. Further, if the queue that is currently served becomes empty, the DeficitCounter is relocated to the next active queue instead of making it zero. This helps in servicing more number of packets in a round. IDWRR offers better results for BE and nrtPS services.