Energy-efficient massive cellular IoT shared spectrum access via mobile data aggregators

Due to the ubiquitous presence of cellular networks and their exemplary success, they have been pushed forward to provide connectivity for Internet-of-things (IoT) applications with mass deployments of sensors and machines. Nevertheless, existing transmission protocols, e.g., orthogonal allocation or spectrum sharing, can be detrimental for both existing cellular users and IoT devices due to increased congestion, interference, or resource splitting. To this end, we propose to complement cellular networks with authorized mobile data aggregators, e.g., drones, that collect data from IoT devices and aggregate them to the cellular network. The proposed cellular architecture is supported by a novel transmission protocol and load-aware power control. The former enables IoT devices to operate over the same channel with existing cellular users, increasing the available spectral resources, whereas the latter constrains the interference on these users. Simulation results are presented to illustrate the performance of the proposed architecture compared to orthogonal allocation and spectrum sharing. It is shown that the proposed architecture significantly improves the energy efficiency of IoT devices, with minimal degradation on the spectral efficiency of existing cellular users.