GEO-Mobile Radio Interface (GEO stands for
Geostationary Earth Orbit), better known as GMR, is an
ETSI standard for
satellite phones. The GMR standard is derived from the
3GPP-family terrestrial digital cellular standards and supports access to GSM/UMTS core networks. It is used by
ACeS,
ICO
is an action-adventure game developed by Japan Studio and Team Ico, and published by Sony Computer Entertainment, released for the PlayStation 2 video game console in 2001 and 2002 in various regions. It was designed and directed by Fumito U ...
,
Inmarsat,
SkyTerra SkyTerra (SKYT), formerly Mobile Satellite Ventures (MSV or MSVLP), was a Reston, Virginia company that developed telecommunications systems that integrate satellite and terrestrial radio communication technologies into one system. In March 2010, t ...
,
TerreStar
TerreStar Corporation (TSTR), formerly Motient Corp. (MNCP - 2000–2007) and ''American Mobile Satellite Corp.'' (AMSC - 1988–2000), was the controlling shareholder of ''TerreStar Networks Inc.'', ''TerreStar National Services, Inc.'' and ''Terr ...
and
Thuraya
Thuraya ( ar, الثريا, Gulf Arabic pron.: ; from the Arabic name for the constellation of the Pleiades, ''Thurayya'') is a United Arab Emirates-based regional mobile-satellite service (MSS) provider. The company operates two geosynchronous ...
.
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There are two widely deployed variants of GMR, both heavily modeled after GSM
The Global System for Mobile Communications (GSM) is a standard developed by the European Telecommunications Standards Institute (ETSI) to describe the protocols for second-generation ( 2G) digital cellular networks used by mobile devices such ...
* GMR-1: The first version of the standard and that has evolved over time into 3 different revisions:
** GMR-1: The basic circuit switched model, more or less corresponding to what GSM
The Global System for Mobile Communications (GSM) is a standard developed by the European Telecommunications Standards Institute (ETSI) to describe the protocols for second-generation ( 2G) digital cellular networks used by mobile devices such ...
Phase 2 is, and using exactly the same core network infrastructure.
** GmPRS: Adding support for packet data. The equivalent of GPRS in the GSM
The Global System for Mobile Communications (GSM) is a standard developed by the European Telecommunications Standards Institute (ETSI) to describe the protocols for second-generation ( 2G) digital cellular networks used by mobile devices such ...
world. Still connected to a 'Gb' style core network.
** GMR-1 3G: Adds support for some new channel types, but the most important changes are in the core network, adding interoperability with UMTS core network components. Contrary to the classic cell network where UMTS
The Universal Mobile Telecommunications System (UMTS) is a third generation mobile cellular system for networks based on the GSM standard. Developed and maintained by the 3GPP (3rd Generation Partnership Project), UMTS is a component of the In ...
and GSM
The Global System for Mobile Communications (GSM) is a standard developed by the European Telecommunications Standards Institute (ETSI) to describe the protocols for second-generation ( 2G) digital cellular networks used by mobile devices such ...
have a radically different air-interface, GMR-1 3G is still very similar to GMR-1 on the Layer 1 side.
* GMR-2: Which is not an evolution of GMR-1 but rather a concurrent standard that has been developed by another group of companies.
GMR-1 is the technology used by Thuraya. GMR-1 3G is the technology used for TerreStar and SkyTerra.
GMR-2 is used by Inmarsat iSatPhonePro.
GMR was developed by TIA and ETSI.
Air Interface Ciphers
Versions of standard and cipher used:["Don’t trust satellite phones"]
* GMR-2 - GEO mobile radio 2 (InmarSat iSatPhonePro). Based on byte operations and 2 S-Boxes from DES.
References
External links
CreonicETSIETSI Publications Download AreaDon’t trust satellite phones – The GMR-1 and GMR-2 ciphers have been broken
Satellite telephony
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