Radio resource scheduling using packet-level service differentiation for video over the LTE downlink

Quality delivery of real-time video over LTE has a high demand on radio resources, and thus imposes a challenging task on the design of a packet scheduler for the LTE base station (eNodeB). When the shared radio resources become less sufficient as the number of user equipments (UEs) increases, the best the conventional schedulers can do is to be both Channel-aware and QoS-aware, and provide flow-level service differentiation. This paper proposes a novel scheduler design called generalized largest weighted delay first (GLWDF) for the LTE downlink, and its novelty lies in the fact that it can provide packet-level service differentiation based on a real-time packet priority scheme within a single video flow, which is implemented by introducing a so-called error propagation length (EPL) priority scheme into the scheduling metric of GLWDF. Our simulation results show that GLWDF outperforms the conventional schedulers, including PF, EXPPF, and MLWDF, in terms of Per-UE throughput, packet delay distribution under a real-time delay budget or late-loss constraint, packet loss rate, and average Y-PSNR.