Wireless Channel Characterization and System Analysis of Complex Utility Tunnel Environments

The evolution of wireless communications has led to the adoption of a wide range of applications not only for the general public, but also including utilities and administrative authorities. Consequently, the huge growth of new city services requires in some specific cases the construction of underground tunnels in order to reduce visual impact within the city center, as well as enabling maintenance and operation works of utilities. One of the main challenges is that inherently, underground service tunnels lack of coverage from exterior wireless systems, such as mobile networks or municipal WLAN networks, which can be potentially dangerous for maintenance personnel working within the tunnels. In this work, wireless channel characterization for urban tunnel scenarios will be analyzed based on the assessment of LoRaWAN and ZigBee technologies operating at 868MHz. For that purpose, a real urban utility tunnel has been modeled and simulated by means of an in-house 3D Ray Launching code and compared with experimental measurements, showing good agreement. The singularity and complexity of the limited tunnel dimensions and the inclusion of additional elements such as service trays, user pathways and handrails have been considered. Results provide an adequate radio planning approach for the deployment of wireless systems in urban utility scenarios, with optimal coverage and enhanced quality of service. Besides, in order to have access to the data obtained by the potential WSN deployed within the tunnels, a solution to store such information in a Cloud is included in the study.