Reusing frequencies of a fixed and/or mobile communications system

A method for reducing interference between a first wireless communications system and a second wireless communications system sharing at least some frequencies of a frequency band, the method comprising:

• establishing an inter-system communications link between the first wireless communications system and the second wireless communications system;
• and
• coordinating the use of the frequency band using the inter-system communications link to thereby reduce interference between the first wireless communications system and the second wireless communications system.

A method for reducing interference between a geostationary satellite communications system and a non-geostationary satellite communications system sharing at least some frequencies of a frequency band, the method comprising:

• establishing an inter-system communications link between the geostationary communications system and the non-geostationary communications system;
• and
• coordinating the use of the frequency band using the inter-system communications link to thereby reduce interference between the geostationary communications system and the non-geostationary communications system.

A wireless communications system configured to provide wireless communications using at least some frequencies that are authorized for use and/or are used by a second wireless communications system, the wireless communications system comprising:

• an inter-system communications link between the wireless communications system and the second wireless communications system configured to coordinate the use of the at least some frequencies;
• and
• an interference reducer configured to reduce interference between the wireless communications system and the second wireless communications system.

An interference reducer configured to reduce interference in a wireless communications system that is configured to use at least some frequencies of a frequency band that is authorized for use and/or is used by a second wireless communications system,

• wherein the interference reducer is configured to use an inter-system communications link between the wireless communications system and the second wireless communications system to reduce interference between the wireless communications system and the second wireless communications system.

A wireless communications system comprising a space-based component and at least one terrestrial component;

• wherein the space-based component is configured to receive a signal from a radioterminal over a plurality of different polarizations and the wireless communications system is configured to provide wireless communications using at least some frequencies that are authorized for use and/or are used by a second wireless communications system;
• wherein the second wireless communications system comprises at least one space-based component and/or at least one terrestrial component.

A method of providing wireless communications in a wireless communications system comprising a space-based component and at least one terrestrial component, wherein the wireless communications system is configured to provide wireless communications using at least some frequencies that are authorized for use and/or are used by a second wireless communications system comprising at least one space-based component and/or at least one terrestrial component, the method comprising receiving a signal at the space-based component of the wireless communications system from a radioterminal over a plurality of different polarizations.