NB-IoT over GEO Satellite: Performance Analysis

NB-IoT (Narrowband Internet of Things) has been introduced by 3GPP with the aim of meeting the 5G requirements for the IoT segment through coverage classes, repetitions, narrower subcarriers, user and control planes optimizations and power saving mechanisms. Recognizing the capability of satellite systems to offer wide coverage and enable cross-countries deployment, 3GPP is considering 5G technologies to support Non-Terrestrial Network (NTN). However, while studies have shown the capability of NB-IoT to meet the 5G latency and capacity expectations in terrestrial networks, the question remains open for the satellite context. In this paper, we consider the necessary mechanisms for adapting NB-IoT to the satellite context and provide a study of the delay of a communication as function of gNodeB parameters, cell specification (size, link budget, satellite altitude) and payload size. Our study adopts the configurations used for the simulation based on the link budget given in the 3GPP Study Item and considers not only the random access procedure but also the whole communication process, with signalling, uplink /downlink messages and connection release. We find that the optimal Block Error Rate for minimizing the delay of the communication and optimizing the spectral efficiency is lower that the one recommended in nominal 5G specification.