Energy efficiency analysis of narrowband Internet of Things with auxiliary active cycles for small data transmission

Publication Date


Document Type


Publication Title

Transactions on Emerging Telecommunications Technologies








Narrowband Internet of Things (NB-IoT) is a cellular-based technology standardized by the Third Generation Partnership Project (3GPP) in Release-13 with the primary focus to support low-power, low-data rate, and delay-tolerant applications. The main contributions of this article are: (a) we describe the architecture of NB-IoT and its evolution in further 3GPP Releases and (b) we develop a semi-Markov based energy-saving model for the NB-IoT device. Different from the other existing approaches which focus on the optimization of power consumption of the NB-IoT device, we propose the addition of a novel Auxiliary State to the conventional NB-IoT Discontinuous Reception (DRX) mechanism. This state facilitates the reduction in energy consumption of the NB-IoT device, especially in case of small data transmission. The performance of the proposed scheme is analyzed in terms of power saving factor and average delay experienced by the device for varying eDRX timer, PSM timer, DRX cycle duration, and DRX active duration values. The proposed model is also evaluated for different arrival rates of the data packets and thresholds on the number of data packets. In this study, we claim that the newly introduced Auxiliary State improves the power saving of the NB-IoT user on the arrival of very small data packets. Numerical results show that the power saving factor increases up to (Formula presented.) and (Formula presented.) by varying the eDRX timer and PSM timer, respectively.


Computer Science