QOS IMPROVEMENT FOR MULTI-MEDIA TRAFFIC, USING EDF -PSO - HYBRID SCHEDULER IN LAYER-2 OF 4G WIRELESS DOWNLINK
Sentthil Vinayakam A. Rajeswari
Downlink schedulers in 4G networks need to allocate bandwidth for inputs of multiple classes of service and meet individual classes QoS requirements, which is a complex work. Conventional scheduling algorithms have limitations in providing best solutions in such vast set of solutions possible in such complex conditions in which high speed multi-media wireless networks operate.
Proposed scheme namely, EDF-PSO Hybrid scheduler is a dynamic, channel aware and QoS aware, time-domain downlink scheduler, designed to work on IEEE 802.16e and 802.16m standards at MAC level. The proposed three stage EDF-PSO Hybrid scheduler consists of 1st stage of modified-EDF, 2nd stage of multi-objective PSO and final EDF rounds in that order. The performance metrics of Goodput, Packet delay and Packet Deadline Miss Ratio for real-time and non-real time connections are compared with existing best of class MAC downlink schedulers. The proposed EDF-PSO Hybrid schduler out-performs the competing schedulers viz EDF, LWDF, FIFO and PSO comprehensively in the mentioned QoS performance metrics for both real and non-real time classes of service. It is able to maintain this best performance upto a traffic intensity of 0.9 and meet max packet deadline specifications excellently. This is simulated and tested for FDD mode of duplexing.
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