Power-Saving Scheme for PON LTE-A Converged Networks Supporting M2M Communications

To cope with the unprecedented growth of Machineto-Machine (M2M) services over cellular networks, this paper envisions an energy-efficient PON LTE-A converged network that combines the high capacity and reliability of PON technology with the flexibility and cost savings of LTE-A network to support M2M applications. In particular, this paper proposes a powersaving scheme that unifies the cyclic sleep mechanism defined for PON´s optical network units (ONUs) and the discontinuous reception (DRX) mechanism defined for LTE´s user equipments (UEs) to reduce the overall power consumption in the envisioned network. For performance evaluation, a comprehensive energy saving model and an end-to-end packet delay analysis for M2M scenarios are presented taking into account both optical backhaul and wireless front-end networks based on an M/G/1 queueing model (for backhaul) and a semi-Markov process (for frontend). Results show that the battery life of M2M devices can be significantly prolonged by extending DRX cycle, while the energy consumption of the optical backhaul network can be minimized by exploiting TDMA scheduling for ONU cyclic sleep implementation. Further, the trade-off between overall energy saving and end-to-end packet delay is studied to specify maximum achievable energy saving while not violating delay constraints.