Opportunistic Scheduling for Delay Sensitive Flows in Wireless Networks

We present an "opportunistic" scheduling policy with the objective of improving delay performance for time-sensitive users in wireless networks. Since packet delay depends on both resource allocation and time-varying capacity of wireless channels, we introduce a search radius (SR) into the framework of packet fair queueing (PFQ) and employ maximum relative SNR (Max-rSNR) as scheduling rule with the purpose of providing short-term temporal fairness guarantee and improving user throughput. We make theoretical analysis of the delay performance of each user and find that each user's delay is directly related to SR, moreover the value of SR should be restricted within a limited range in order to provide better delay performance to each user. Based on this, we propose a feasible iterative algorithm to achieve an appropriate SR. We conduct an extensive set of simulations, which characterizes the performance of our scheduling scheme.