Enhancing power efficiency through semi-markov modeling of Narrowband Internet of Things devices in 5G networks

Aiming to accommodate a large number of devices for low-bandwidth data transmission, Narrowband Internet of Things (NB-IoT) encapsulates the concept of the Internet of Things [1]. However, an efficient power conservation paradigm for battery-powered NB-IoT devices is crucial. In addition to the traditional Discontinuous Reception (DRX) method, efficient beamforming helps to conserve device battery [2]. Further, the extended Discontinuous Reception (eDRX) mode and Power Saving Mode (PSM) in Radio Resource Control (RRC) inactive mode increase the effect of sleep when there is no data available for the device to serve [3, 4]. Using stochastic models, power-saving techniques for NB-IoT devices are investigated in this paper. This paper proposes a semi-Markov model (SMM) for beam measurement and beamforming-based DRX in RRC modes. The SMM’s steady-state probabilities are calculated using a two-stage method [5]. The numerical results demonstrate the contribution of efficient beamforming, eDRX state, and PSM state to the enhancement of NB-IoT devices’ power efficiency.