Analysis of Massive IoT Networks in Nearest and Macro Diversity Reception Regime

In this overview paper, we present a reliability analysis for massive Internet of Things (IoT) connectivity in cellular networks. In such networks, IoT devices intermittently and unpredictably transmit short data packets to base stations (BSs), often causing interference with other devices sharing the same uplink channel. Assuming a slotted ALOHA random access scheme under Nakagami fading, we investigate the probability that a short-packet transmission from an IoT device fails to be decoded, in the nearest BS and macro diversity reception regime. Using a combination of finite block-length (FBL) information theory and stochastic geometry, we derive error probability expressions. These FBL-based results are compared with existing asymptotic expressions, which assume the transmission of asymptotically long packets. Numerical results confirm the accuracy of the derived expressions and their relevance to the design and performance evaluation of massive IoT systems across a wide range of parameters.