Opportunistic QoS-Aware Fair Downlink Scheduling for Delay Sensitive Applications Using Fuzzy Reactive and Proactive Controllers

We consider in this paper downlink scheduling at the MAC layer for delay sensitive traffic in wireless systems based on Orthogonal Frequency Division Multiple Access (OFDMA), such as the recent LTE/LTE-A wireless standard. In the literature, time diversity is exploited in scheduling by using the Head of Line (HoL) packet delay and time-averaged bit throughput. However, under diverse channel conditions and variable rate characteristics of video traffic, the average throughput along with the HoL packet delay does not provide a fair system. We advocate here that, instead of utilizing the average throughput, the utilization of time-averaged channel quality along with the HoL packet delay and Packet Loss Rate (PLR) can reduce the Quality of Service (QoS) violations of low channel quality users and thus provide a fair system.