The Spectral and Energy Efficiency of Ultra-Dense IoT Networks

As radio access networks (RANs) are becoming more densified, their design has shifted from considering capacity and coverage only to considering capacity, coverage and energy efficiency (EE). Also, sleep modes are an effective approach for enhancing the EE of densified RANs. This paper investigates the EE of a densified RAN for an Internet-of-Things (IoT) use case by employing a 3-dimensional (3D) Homogeneous Poisson Point Process (HPPP) to model the IoT base station (BS) distribution, which accounts for variation in BS height z as well as its x, y position. The EE performance of an IoT RAN is evaluated as the ratio of RAN throughput to RAN power consumption with the number of base stations varied as a parameter. The results demonstrate that sleep mode has the potential to make dense IoT networks energy efficient providing base stations serving only inactive or unconnected IoT devices are completely turned off, including the backhaul.