International Committee on Global Navigation Satellite Systems (ICG): Providers' Forum
A Providers' Forum was established at the second meeting of the International Committee on Global Navigation Satellite Systems (ICG) in 2007, in Bangalore, India, with the aim to promote greater compatibility and interoperability among current and future providers of the Global Navigation Satellite Systems (GNSS). The current members of the Providers Forum, including China, India, Japan, the European Community, the Russian Federation and the United States, addressed key issues such as ensuring protection of GNSS spectrum and matters related to orbital debris/orbit de-confliction.Providers' Forum Principles of Compatibility and Interoperability and their further definition
Global and regional system providers at the third meeting of the Providers' Forum in 2008, in Pasadena, United States of America, agreed that at a minimum, all global navigation satellite systems (GNSS) signals and services must be compatible. To the maximum extent possible, open signals and services should also be interoperable, in order to maximize benefit to all GNSS users. For many applications, common carrier frequencies are essential to interoperability and commonality of other signal characteristics is desirable. In some cases, carrier frequency diversity may be preferable to improve performance. The Providers' Forum will continue to investigate the benefits of carrier frequency commonality and diversity, as well as of compatibility and interoperability, as these latter terms are defined below:Interoperability
Interoperability refers to the ability of global and regional navigation satellite systems and augmentations and the services they provide to be used together to provide better capabilities at the user level than would be achieved by relying solely on the open signals of one system:
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Interoperability allows navigation with signals from different systems with minimal additional receiver cost or complexity;
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Multiple constellations broadcasting interoperable open signals will result in improved observed geometry, increasing end-user accuracy everywhere and improving service availability in environments where satellite visibility is often obscured;
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Geodetic reference frames realization and system time steerage standards should adhere to existing international standards to the maximum extent practical;
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Any additional solutions to improve interoperability should be encouraged.
Compatibility
Compatibility refers to the ability of global and regional navigation satellite systems and augmentations to be used separately or together without causing unacceptable interference and/or other harm to an individual system and/or service:
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The International Telecommunication Union provides a framework for discussions on radiofrequency compatibility. Radiofrequency compatibility should involve thorough consideration of detailed technical factors, including effects on receiver noise floor and cross-correlation between interfering and desired signals;
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Compatibility should also respect spectral separation between each system's authorized service signals and other systems' signals. Recognizing that some signal overlap may be unavoidable, discussions among providers concerned will establish the framework for determining a mutually acceptable solution;
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Any additional solutions to improve compatibility should be encouraged.