Power-saving coercive sleep mode for machine type communications

Machine type communication (MTC) is deemed as one of the killer applications in 5G mobile communication networks, for which power saving is an important yet challenging issue. In current cellular networks, most proposed power-saving mechanisms are designed for human-to-human (H2H) communications, and thus not applicable to MTC. Hence, it is imperative to design effective power-saving mechanisms for MTC in 5G networks. 3GPP has proposed Discontinuous Reception (DRX) mechanism to allow users receive data at specified time slots and turn off the radio module at other time slots, aiming at reducing power consumption. In this paper we design an energy efficient coercive sleep mode (CSM) to reduce power consumption, based on the idea of DRX. In CSM, a metric “NUMBER” is introduced to record the number of packets in addition to inactivity timer in DRX. We use a semi-Markov process to model mechanism, for evaluating the power saving factor and wake up latency. We also employ simulation to examine the impact of DRX parameters on system performance. Numerical results show that CSM achieves significantly higher energy efficiency and is thus appropriate for low cost MTC, compared with standard DRX.