Spectrum clearing - Frequency spectrum is typically allocated and policed by a national regulator. Licenses for specific blocks of spectrum are time limited and can change their use as new technologies and applications evolve. When a new license is issued, the new spectrum owner needs to survey the spectrum to confirm legacy users have ceased transmitting.
Shared spectrum monitoring - It is becoming increasingly common for more than one technology to be allocated access to the same block of spectrum. In order for operators to understand how this will affect their long term ability to provide a service, they need to continuously monitor activity in the spectrum to build up a understanding of likely availability over days and months.
Satellite ground station monitoring - Satellite downlink signals typically arrive at the surface of the earth with very low signal level, and the latest generation of satellites are starting to use millimeter wave frequencies for these downlinks, including 8 to 9 GHz X band for space research, 12 GHz Ku band for domestic TV broadcast and 23 to 27 GHz for fixed link broadcasts. The sensitivity of satellite downlink receivers make then very susceptible to interfering signals. Continuous monitoring of the in band and adjacent frequencies is essential to maintain robust communications and understand if and when additional filtering may be required.
Critical site security - Many government defense and commercial sites have experienced aggressive and intentional interference from hostile agents. On site communications are critical for the smooth running of large sites with many interdependent automated systems. Monitoring and early detection of hostile transmissions is essential to effective site operation. Examples of venerable sites include prison services, transport hubs and government offices.
Interference monitoring - Major sporting events, festivals and conferences bring together multiple agencies to a single location for maybe only a few days or weeks. Each contributing agency often has unique communications and telematics requirements that require temporary licensing. Typical examples include international motor racing events, football tournaments and global music festivals. To ensure all the stakeholders’ systems are transmitting on their approved frequencies and not interfering requires stick monitoring of the spectrum.
Regulatory enforcement - National regulators need to police spectrum activity in large urban areas. Large cities will have multiple licensed transmitters and unless the spectrum is policed, there will be interference and degraded p[performance across all systems.
