Energy-efficient DRX scheduling for multicast transmissions in 3GPP LTE-Advanced wireless networks

The 3GPP LTE-A (Long Term Evolution-Advanced) is the most promising technology for next-generation wireless communications. It provides high transmission rate up to 1 Gbps and supports plentiful multimedia services, especially for those bandwidth required multicast type of services, such as IPTV and Voice/Video-over-IP services. However, when users activate more services at their user equipments (UEs), more energy is consumed. To save UEs´ energy, the LTE-A standard defines the Discontinuous Reception Mechanism (DRX) to allow UEs turning off their radio interfaces and going to sleep to save energy when no data needs to be received. But, how to optimize DRX configurations for UEs is still left as an open issue. In this paper, we address the DRX optimization problem for multicast services, which asks how to guarantee the quality of service (QoS) of the multicast streams while minimize UEs´ wake-up time. We propose an energy-efficient scheme to tackle this problem. The scheme tries to arrange the best multicast data reception orders to reduces UEs´ wake-up periods while consider the resource collision avoidance. Simulation results show that the performance of the proposed scheme is effective even if the network is under saturated condition.