ADAPTIVE MODIFIED LOW LATENCY QUEUING ALGORITHM FOR REAL TIME TRAFFIC IN WiMAX NETWORKS

Abstract

Providing service guarantees for real time applications like voice and video are key concerns in WiMAX (IEEE802.16) networks. Proper resource management with the help of an appropriate packet scheduling algorithm achieves the required service guarantee. Scheduling algorithm determines the order of packet delivery among many packets which are waiting to be serviced from the queue. This paper enhances the Modified Low Latency Queuing (MLLQ) algorithm to improve the Quality of Service (QoS) and to ensure service guarantee for real time applications. We propose an Adaptive MLLQ (AMLLQ) algorithm as an extension of the work done in the MLLQ. The MLLQ algorithm introduced an additional Strict Priority Queue (SPQ) in the LLQ to improve the QoS for video applications. The AMLLQ algorithm determines the order of scheduling between the two SPQs dynamically by considering the queue size. The SPQ which exceeds the queue threshold will be processed preferentially than the other SPQ. Simulation results show that the AMLLQ outperforms the MLLQ with respect to throughput and delay for the real time applications.

Keywords

• Low Latency Queuing
• Real time applications
• QoS
• Scheduling algorithms
• WiMAX.