Spectrum sharing between an aircraft-based air-to-ground communication system and existing geostationary satellite services
View Patent ↗The present Spectrum Sharing System implements spectrum reuse between aircraft-based Air-To-Ground (ATG) communication systems and Geostationary Satellite Service systems. This is accomplished by managing the radio frequency transmissions in the volume of space in which the aircraft operates, with interference between the Spectrum Sharing System and the Geostationary Satellite Service system being reduced by implementing reversed uplink and downlink radio frequency paths in the common spectrum. The Spectrum Sharing System also avoids interfering with Geostationary Satellite Services' earth stations which are pointed towards the satellites' orbital arc by relying upon a combination of the earth stations' highly directive antenna patterns and the Spectrum Sharing System ground station antenna pattern, and to avoid interfering with satellites in their orbital arc by assuring that power levels radiated in that direction by the Spectrum Sharing System ground stations are below the level that would create interference.
1. A system for providing wireless communication services to communication devices that are located in an aircraft that is operational in a selected coverage area, wherein at least one geostationary satellite communication system is operational in the selected coverage area and uses a plurality of earth stations, each of which transmit radio frequency signals in a narrow-shaped beam that is directed skyward, in a direction toward the equator of the earth, to a satellite at a first radio frequency and receive radio frequency signals from the satellite, at a second radio frequency, using the narrow-shaped beam that is directed skyward at the satellite, comprising:
at least one ground station for creating a radio frequency coverage area that provides radio frequency links to aircraft that are operational in the radio frequency coverage area, comprising:
a transmitter that generates a radio frequency signal at the second radio frequency for transmission to the aircraft; and
an antenna that produces a broad-shaped beam of the radio frequency signal generated at the second radio frequency, which broad-shaped beam is directed skyward in a direction toward the equator of the earth and which substantially fails to radiate into any narrow-shaped beam of the earth stations of the geostationary satellite communication system.
2. The system for providing wireless communication services of claim 1 further comprising:
wherein the aircraft uses the first radio frequency to transmit radio frequency signals to the ground station.
3. The system for providing wireless communication services of claim 2 wherein the at least one ground station comprises:
a receiver which operates at the first radio frequency to receive radio frequency signals transmitted from an aircraft to the ground station.
4. The system for providing wireless communication services of claim 1 further comprising:
wherein the antenna of the at least one ground station produces a broad-shaped beam that is directed skyward to avoid near-ground portions of the narrow-shaped beam of nearby earth stations.
5. The system for providing wireless communication services of claim 1 further comprising:
wherein each ground station is located at sites which are outside of a path of the narrow-shaped beam.
6. A method for providing wireless communication services to wireless communication devices that are located in an aircraft that is operational in a selected coverage area, wherein at least one geostationary satellite communication system is operational in the selected coverage area and uses a plurality of earth stations, each of which transmit radio frequency signals in a narrow-shaped beam that is directed skyward, in a direction toward the equator of the earth, to a satellite at a first radio frequency and receive radio frequency signals from the satellite, at a second radio frequency, using the narrow-shaped beam that is directed skyward at the satellite, comprising:
operating at least one ground station for creating a radio frequency coverage area that provides radio frequency links to aircraft that are operational in the radio frequency coverage area, comprising:
generating a radio frequency signal at the second radio frequency for transmission to the aircraft; and
operating an antenna to produce a broad-shaped beam of the radio frequency signal generated at the second radio frequency, which broad-shaped beam is directed skyward in a direction toward the equator of the earth and which substantially fails to radiate into any narrow-shaped beam of the earth stations of the geostationary satellite communication system.
7. The method for providing wireless communication services of claim 6 further comprising:
wherein the aircraft uses the first radio frequency to transmit radio frequency signals to the ground station.
8. The method for providing wireless communication services of claim 6 further comprising:
wherein the antenna of the at least one ground station produces a broad-shaped beam that is directed skyward to avoid near-ground portions of the narrow-shaped beam of nearby earth stations.
9. The method for providing wireless communication services of claim 6 wherein operating the at least one ground station comprises:
operating a receiver at the first radio frequency to receive radio frequency signals transmitted from an aircraft to the ground station.
10. The method for providing wireless communication services of claim 6 further comprising:
wherein each ground station is located at sites which are outside of a path of the narrow-shaped beam.