Access Delay Analysis and Optimization of NB-IoT Based on Stochastic Network Calculus

NB-IoT(Narrow Band Internet of Things) is a kind of communication technology based on cellular networks, which has the features of low power consumption, low cost, large connection and wide coverage. It has broad application potentials in the IoT market. Network performance evaluation facilitates the deployment of NB-IoT devices and system optimization. In this paper, we model the data flow arrival process and service process of NB-IoT under different distributions individually and propose a method to analyze the access delay bounds in NB-IoT utilizing stochastic network calculus. Simulations show that this method can predict the system delay under uniform distribution reasonably and effectively. For the case where massive IoT devices access simultaneously following the Beta distribution, we propose two optimization strategies: region clustering and dynamic service rate adjustment. The optimized NB-IoT access model can reduce the network congestion caused by the simultaneous access of all devices significantly, and improve network performance when a large number of devices try to access, which can be used to guarantee the QoS of the NB-IoT access networks.