A Multi-Technology Opportunistic Platform for Environmental Data Gathering on Smart Cities

Having connectivity as a pivotal element, Internet of Things (IoT) systems rely on wireless technologies to provide communication to end devices. A growing set of technologies, designated as Low-Power Wide Area Networks (LPWANs), are becoming prominent technologies for smart cities applications due to their long range, effective cost and energy efficiency. The purposed multi-technology opportunistic platform for environmental data gathering addresses the heterogeneity of IoT devices, through the employment of multi-technology communications, LoRa and WiFi, and serves as infrastructure for a network with opportunistic communication capabilities. Furthermore, to increase the operability of the proposed platform, we present and evaluate a novel Medium Access Control (MAC) scheme capable of supporting a reliable communication through LoRa technology over a multi-sink environment without direct contact. The results show that, by increasing the number of LoRa sinks, with the purpose of covering a wider area, the proposed MAC protocol is able to manage efficiently the medium access of each data gathering unit, therefore increasing the channel occupancy and reducing the delay of each transmission.