An Enhanced Energy Saving Strategy for an Active Drx in Lte Wireless Networks

When using a Discontinuous Reception (DRX) mechanism in Long Term Evolution (LTE) for wireless communication of high-speed data, two different operational modes are employed: Idle DRX and Active DRX. In this paper, in order to guarantee a low latency while reducing the energy consumption, we introduce a sleep-delay timer before the system enters into a sleep state from a working state, and consider a strategy to enhance energy saving for the Active DRX where the system switches to a sleep state from a working state. We call the time length of the sleep-delay timer a sleep-delay period and the switching period a waking-up procedure. We build a discrete-time queueing model with two stages of vacations by taking into account the sleep-delay period and the waking-up procedure to model the system operation. By using an embedded Markov chain, we present an exact analysis to numerically evaluate the performance of the system model. We then give the formulas for the performance measures in terms of handover ratio, energy consumption and average latency of the data frames, and present numerical experiments to investigate the influence of the configuration parameters on the system performance. Finally, by considering the trade-off between different performance measures, we optimize the enhanced energy saving strategy for the Active DRX.