On the Performance Improvement of IoT Networks Using Relay-Based Communications

Internet of Things (IoT) is a network of disparate objects enabled to exchange data with other objects to implement smart applications. In near future, billions of devices are expected to be connected to IoT through wireless connections. Due to the limited capacity of the wireless medium, the effective resource allocation is a highly important factor to improve the network performance, especially in the presence of a large number of devices. In this work, we investigate the problem of allocating resources in an OFDMA-based wireless IoT network, including channel assignment and power control, to satisfy the SINR requirements of all the devices in a scalable manner. The Primary Resource Allocation Problem (PRAP) is formulated as a Mixed-Integer Linear Programming (MILP) problem which is efficiently solvable by mathematical methods. We next develop a new relay-based communication model that results in a significantly improved network performance. The resource allocation in this model is formulated as the Relay-based Resource Allocation Problem (RRAP). Due to their computational complexity, the Relay-based Resource Allocation Scheme (RRAS) is devised to provide a suboptimal solution for RRAP and PRAP. The numerical results show that the relay-based communication model results in highly improved SINR for devices, network outage ratio, and transmission power.