D2D Communications for Enabling Internet of Things Underlaying LTE Cellular Networks

Internet of Things (IoT) is an emerging paradigm that provides the future network of interconnected devices. On the other hand, Device-to-Device (D2D) communication is considered a promising technology that providing a mechanism for sharing the radio resources of LTE eNodeB for efficient spectrum utilization. A novel method is introduced in this paper to provide the required connectivity between a group of IoT devices (IoTDs) and its associated IoT gateway (IoT-GW) using D2D communication underlaying LTE networks. In this context, a quality of service (QoS) based resource allocation scheme for IoTDs is proposed for enabling IoT services underlaying LTE networks. The proposed scheme is based on two main steps. In the first step, the set of allowed cellular user equipment (CUE) reuse candidates for each IoTD is determined taking into consideration the QoS requirements for both of CUEs and IoTDs. In the second step, the optimal resource allocation for each IoTD is determined. The optimization problem is modeled as a maximum bipartite matching problem that finds the optimal CUE reuse candidate for each IoTD with the objective to maximize the total number of IoTDs that can be admitted. Simulation results showed that the proposed method can be used to provides an efficient D2D-based IoT connectivity underlaying LTE cellular networks with outstanding performance in terms of access rate and achieved network throughput gain.