System and method for mobile communications in coexistence with established communications systems

A communications system for providing communications with a mobile user in the frequency bands and in the geographic vicinities of different communications services having fixed positions and that operate in sub-bands that use some but not all of the frequency band as the mobile user, while avoiding mutual interference between the mobile user and the different communications services, the communications system comprising:

• a mobile communication device used by the mobile user, the communication device being responsive to a frequency control signal to select the frequency sub-band in which it operates;
• a plurality of surface nodes adapted to communicate with the mobile communication device;
• a memory in which is stored geographic and frequency descriptions of the different communications services thereby defining an interference zone for each of the different communications services;
• a position locating system adapted to determine the position of the mobile user and provide a position signal;
• a processor adapted to receive the position signal, access the memory to retrieve the descriptions of the interference zones of the communications services, compare the position of the mobile user to the interference zone descriptions and if the user is determined to be within an interference zone, provide a frequency control signal to the mobile communication device to select a frequency sub-band in the frequency band other than the frequency sub-band or sub-bands of the communications service of the interference zone in which the mobile user is located;
• and
• a surface node control center, wherein the surface node control center comprises the position locating system, the processor, and the memory, the surface node control center communicating the frequency control signal from the processor to the mobile communication device through a surface node.

A communications system for providing communications with a mobile user in the frequency bands and in the geographic vicinities of different communications services having fixed positions and that operate in sub-bands that use some but not all of the frequency band as the mobile user, while avoiding mutual interference between the mobile user and the different communications services, the communications system comprising:

• a mobile communication device used by the mobile user, the communication device being responsive to a frequency control signal to select the frequency sub-band in which it operates;
• a plurality of space nodes adapted to communicate with the mobile communication device;
• a memory in which is stored geographic and frequency descriptions of the different communications services thereby defining an interference zone for each of the different communications services;
• a position locating system adapted to determine the position of the mobile user and provide a position signal;
• a processor adapted to receive the position signal, access the memory to retrieve the descriptions of the interference zones of the communications services, compare the position of the mobile user to the interference zone descriptions and if the user is determined to be within an interference zone, provide a frequency control signal to the mobile communication device to select a frequency sub-band in the frequency band other than the frequency sub-band or sub-bands of the communications service of the interference zone in which the mobile user is located;
• and
• a space node control center, wherein the space node control center comprises the position locating system, the processor, and the memory, the space node control center communicating the frequency control signal from the processor to the mobile communication device through a space node.

A method for communicating with a mobile user having a communications device in a frequency band and in the geographic vicinity of a different communications service that operates in at least one sub-band that uses some but not all of the frequency band, while avoiding mutual interference between the mobile user and the different communications service, the method comprising the steps of:

• storing in a memory a geographic and frequency description of the different communications service thereby defining an interference zone for the different communications service;
• determining the position of the mobile user;
• accessing the memory to retrieve the description of the different communications service;
• and
• comparing the position of the mobile user to the interference zone of the different communications service and if the user is determined to be within the interference zone, providing a frequency control signal to the mobile communication device to select a sub-band in the frequency band other than the frequency sub-band or sub-bands of the communications service.