OsmocomGMR

h1. GEO Mobile Radio

This is the homepage of the Osmocom sub-project _GEO Mobile Radio_.

It is collecting information and software related to the ETSI GEO Mobile Radio specification and its practical implementations like the [[Thuraya]] satellite phone network

GEO Mobile Radio is a set of specifications describing a satellite based mobile phone network.

h2. Radio aspects

It uses the L-band frequencies  1634 to 1656 MHz (earth to space) and 1532.5 to 1554.5 MHz (space to earth) for communication

between mobile phones and the respective satellites.  The polarization is circular (left) and the modulation is pi/4 QPSK, using

a channel spacing of 31.25 kHz

h2. Index

* [[GMR_Specifications]] -- An Introduction and Overview into the GMR specifications

** [[SpeechCodec]] -- The voice codec

** [[A5-GMR-1]] -- The cipher

* Devices:

** [[Thuraya_SO2510]] -- A popular handset for use in the [[Thuraya]] system.

** [[Thuraya_SG2520]] -- A dual-mode GSM/ [[Thuraya]] handset running WindowsCE.

* [[Thuraya_Beams]] -- Information about the Thuraya beams

** http://bit.ly//nInTOi -- Google Maps view of the Thuraya beams that we have found so far

** https://goo.gl/Zc3uax -- Google Maps view of the Echostar 21 beams that we have found so far

* [[OsmoGMR_Software]] -- Software that we wrote for GMR analysis

** [[GettingStarted]] -- A small guide to get you going

** "Browse code":https://gitea.osmocom.org/satellite/osmo-gmr/ -- Browse the [[gmr:]] source code

* [[Receiver_Setup]] -- How to receive GMR signals coming down from a satellite

h2. Presentations

* 28C3 talk by Sylvain

** Description: https://events.ccc.de/congress/2011/Fahrplan/events/4688.en.html

** Video: http://media.ccc.de/browse/congress/2011/28c3-4688-en-introducing_osmo_gmr.html

** Slides: http://events.ccc.de/congress/2011/Fahrplan/attachments/2027_28c3_introducing_osmocom_gmr.pdf

* Recording of a "Wireless Hacking: GMR-1 / Thuraya" talk by Sylvain Munaut in the Moscow hackerspace Neuron.

** Video: http://www.youtube.com/watch?v=IpZPamI2vTk

* 31C3 talk by Sylvain

** Description: https://events.ccc.de/congress/2014/Fahrplan/events/6267.html

** Video: http://media.ccc.de/browse/congress/2014/31c3_-_6267_-_en_-_saal_g_-_201412271600_-_osmo-gmr_what_s_up_with_sat-phones_-_sylvain_munaut.html

** Slides: https://events.ccc.de/congress/2014/Fahrplan/system/attachments/2496/original/31c3_gmr.pdf

h2. Community

* IRC: #osmocom on libera.chat

* Mailing list : http://lists.osmocom.org/mailman/listinfo/gmr (Please make sure you read the [[cellular-infrastructure:MailingListRules]] before you start posting)