Design and Implementation of the NB-IoT Downlink System on OpenAirInterface Platform

Narrowband Internet of Things (NB-IoT) is an emerging technology introduced by 3GPP Release 13 which supports the low power consumption in wide coverage conditions. With the rapid development of NB-IoT system, more and more novel technologies and algorithms based on NB-IoT have been proposed. However, there is no universal platform to evaluate and validate the proposed algorithms. To solve this problem, an NB-IoT downlink platform based on OpenAirInterface (OAI) is developed in this paper. To help understand this platform, the architecture and workflow are presented in brief. Then, we propose the design scheme and introduce the implementation. At the same time, the repetition mechanism is highlighted. Finally, the system scenario is constructed and the experiments are implemented to validate the performance of the NB-IoT downlink system. The results demonstrate that the NB-IoT downlink platform is correctly deployed and the implement of the repetition mechanism increases stability in exchange for sacrificing resources. This platform can be used to evaluate the NB-IoT system and demonstrates its potential for machine-type communication (MTC) technology.