Abstract
In this paper, we present a LoRa based city-scale testbed that employs several sensing devices scattered across the urban area to characterize air quality and weather conditions in real-time. The installation is augmented through a custom link quality evaluation framework that continuously monitors the Packet Delivery Ratio versus RSSI relation to characterize the performance of LoRa standard under realistic conditions. Experimental results, collected over a period of 2 months, efficiently analyze LoRa's performance across a wide range of protocol configurations. Finally, we also present in-lab experiments that characterize the efficiency of LoRa modules in terms of power and energy efficiency per bit, along with valuable insights aimed at the development of energy efficient protocol improvements.