Internet of Reliable Things: Toward D2D-enabled NB-IoT

A growing number of connected IoT devices makes it more and more difficult for the network to provide the desired reliability in any deployment scenario. The advent of NB-IoT technology opens new possibilities for low-power long-range IoT applications. However, the design of the standard introduces high battery drainage in the situations when the radio conditions between the UE and the eNB are poor. Device-to-Device (D2D) communication is considered a promising technology to address this problem, since D2D makes it possible for the end-devices to exchange the data without the assistance of the base stations. In this work, we study how NB-IoT applications in general can benefit from enabling D2D communication. We focus on assuring reliability and QoS parametres for critical Internet of Things (IoT) use cases. We provide an overview of the state-of-the-art approaches, identify the realisation challenges and highlight the future research directions.