A Customer Success Story: A PoC of Real Time Communication System between Drone and Ground Base Stations using HFSS and STK

One of the biggest telecom service providers in Japan - Softbank is developing a system that can support emergencies such as earthquake or tsunami, where drones could be used to deliver necessary daily items and help with evacuations. To ensure safety and effectiveness of this system, pre-assessment on flight route must be done. Multiple communication links are established between drone’s transceiver and pre-existing base stations owned by Softbank. And by analyzing the signal quality, i.e., link budget of those links, we can select the best route for each drone. Furthermore, by considering the effects of environment (climate, surrounding buildings, interferers), it is possible re-route the drone dynamically in real-time with support of the UAS Traffic Management System (UTM). This PoC is done in STK and HFSS. We use HFSS to model antennas for base stations and mobile receiver attached on drone. Effects of platform on antenna characteristics are considered with high accuracy, given the gold standard of HFSS FEM solver. Scenarios are built in STK, given the actual route of several trial test flights. Also, terrestrial, buildings, and base stations are configured as close as possible to the real test flight environment. LTE link budget analysis and data post processing are done in MATLAB to output well-known signal indicators such as RSRP, RSRP and RSSI. Simulation and measurement results show good correlations, which meet the customer’s expectation. This PoC was press released last year in Japan and received many attentions that could turn out to be a milestone for future HAPS (High Altitude Platform Station) mobile business.