Spectrum Management: RF-Spectrum Surveillance and Data Collection
Airborne Spectrum Monitoring System
Effective management of frequency spectrum by spectrum managers (e.g. ICASA) is a major priority for all countries. As spectrum is a limited resource, spectrum monitoring serves as the eyes and ears of the spectrum managers, being used to monitor breaches of regulations, incorrect calibration of transmission equipment, and to monitor the addition of illegal transmitters/jammers. These breaches of regulations can cause interference and interruptions of communication services, which can cause social and economic impairments in countries. In addition, efficient and flexible spectrum monitoring is imperative in national security operations.
To date, spectrum managers have been utilising labours and hazardous techniques such as sending technicians with a handheld spectrum analyser up a cell tower to monitor RF spectra on each antenna on the cell tower. This technique places the technicians at risk of falling off the cell tower and the company sending the technician/ tower climber at risk of a lawsuit/ settlement. In 2018 news article released by Standford Law School, Multinational Tower Company AT&T Inc. was part of a $30M settlement in tower fall suit by a tower climber.
Vodacom Group Limited; a South African mobile communication company with customers in over 32 African countries, in collaboration with RBI-tech and Omnipresent Global (Pty) Ltd conducted a case study to ascertain the feasibility of an airborne spectrum monitoring system. The system utilized drone technology, a spectrum monitoring device and software. Our role was to retrofit the drone with a handheld spectrum monitoring tool, operate the drone and produce reports of the readings to RBI-tech for further interpretation
We observed the optimal range to operate the drone from the tower structure for the detection of RF activity, known and unknown. In addition to this we observed the drone limitations such as battery life and RF interference on the drone itself (i.e. drones connected to a ground transmitter using 2.4 GHz frequency). Our conclusion was that this application was feasible from a technology perspective and would only be commercially viable once regulations and insurance policies are optimised in South Africa.