Sensitivity Analysis of the Optimal Parameter Settings of an LTE Packet Scheduler

Advanced packet scheduling schemes in 3G/3G+ mobile networks provide one or more parameters to optimise the trade-off between QoS and resource efficiency. In this paper we study the sensitivity of the optimal parameter setting for packet scheduling in LTE radio networks with respect to various traffic and environment aspects. For our investigations we consider a reference packet scheduling algorithm containing elements of proportional fairness and packet urgency to support mixes of real-time and non-real-time traffic. We present extensive simulation results showing the impact of traffic characteristics (like file size distribution, traffic mix) and environment conditions (regarding e.g. multipath fading and shadowing) on the optimal parameter setting. Although, in some cases, efficiency gains of about twenty percent can be achieved by proper tuning of the scheduling parameters, the overall view from our investigations is that a single, robust setting of the parameters can be determined which provides near optimal trade-offs under almost all practically relevant conditions.