Global System for Mobile Communications (GSM)

From Signal Identification Wiki
(Redirected from GSM)
Jump to: navigation, search

2G (GSM) Global System for Mobile Communications
Frequencies 450 MHz,850 MHz,900 MHz,1800 MHz,1900 MHz
Frequency Range 450 MHz - 1900 MHz
Mode RAW, AM, FM
Modulation GMSK
Emission Designator
Bandwidth 200 kHz
Location Worldwide
Short Description GSM is a 2G digital cellular network standard developed by ETSI. As of 2014 it has become the default global standard for mobile communications.
I/Q Raw Recording
Audio Sample

GSM (Global System for Mobile Communications, originally Groupe Spécial Mobile), is a standard developed by ETSIEuropean Telecommunications Standards Institute. An independent, not-for-profit, standardization organization in the telecommunications industry in Europe, developing global telecommunications standards. to describe the protocols for second-generation (2G) digital cellular networks used by mobile phones, first deployed in Finland in July 1991. As of 2014 it has become the default global standard for mobile communications - with over 90% market share, operating in over 219 countries and territories. As the need for more low-band 5G and 4G networks grow, operators around the world began phasing out GSM to re-farm spectrum. In the U.S, AT&T shut down GSM in 2017 while T-Mobile GSM continues to operate until 2024. In Australia, Optus GSM was decommissioned in 2017.


GSM Traffic Channels (TCHs)

GSM Non-Hopping Downlink, received with NFMNarrowband Frequency Modulation:

GSM Non-Hopping Uplink:

GSM Hopping and Non-Hopping Downlink, received with AMAmplitude Modulation:


Info from Wikipedia page GSM Frequency Bands

System Band Uplink (MHzMegaHertz (MHz) 10^6 Hz) Downlink (MHzMegaHertz (MHz) 10^6 Hz) Channel number
GSM-850 850 824.2 – 849.2 869.2 – 893.8 128 – 251
PCS-1900 1900 1850.2 – 1909.8 1930.2 – 1989.8 512 – 810
E-GSM-900 900 880.0 – 915.0 925.0 – 960.0 975 – 1023, 0 - 124
DCS-1800 1800 1710.2 – 1784.8 1805.2 – 1879.8 512 – 885

GSM-850 and PCS-1900 (shaded in blue) have been deployed in NAR and CALA (North American Region [Canada and the US], Caribbean and Latin America)

E-GSM-900 and DCS-1800 (shaded in yellow) have been deployed in EMEA and APAC (Europe, the Middle East and Africa, Asia-Pacific)

Decoding Software[edit]

Hobby Level Software

Professional Software

Decoding Tutorials[edit]

Video Examples[edit]

Additional Links[edit]

Additional Images[edit]