Interference Measurement Experiment of Mobile Base Station Downlinks Using an Aircraft in Satellite-Terrestrial Integrated Mobile Communication Systems

The National Institute of Information and Communications Technology (NICT) has been studying a new mobile communication system, named Satellite-Terrestrial Integrated Mobile Communication Systems (STICS)[1]. The STICS is a mobile phone system in which terrestrial mobile and satellite communication systems coexist, and is seamlessly integrated in the same frequency band. We aim for the realization of a system which maximizes the total communication throughput by controlling the system resources such as the frequencies, output power and antenna beams of the satellite system while avoiding the interference between the terrestrial and the satellite terminals depending on their traffic distribution and changes. The amount of the interference from the terrestrial base stations to the satellite is one of the important parameters for the STICS and must be evaluated. There are no studies that evaluate the amount of radiation of cellular base stations toward the sky to our knowledge. We therefore conducted an experiment to measure the radiation power of the existing mobile base stations toward satellites using an airship with array antenna as part of the interference evaluation. This paper gives the overview of the experiment and some of the results.