Mode GSM R

GSM-R: the public broadcast information of railway GSM cells.

Group	Cellular & rail
Default frequency	922.8 MHz
Default sample rate	5 Msps
In the mode list	Railway, 921 - 925 MHz

Step-by-step: Tutorial-GSM-R

What GSM-R is

GSM-R is the railway version of GSM, around 921 to 925 MHz in Europe, used for train control and communication.

Frequencies and settings

Railway GSM broadcast (BCCH, 921 - 925 MHz).

Setting	Value
Start frequency	922.8 MHz
Tuning range of the mode table	860 to 960 MHz
Sample rate asked	5 Msps
Lowest working rate	1 Msps
Channel width	4.8 MHz

OnAir takes any frequency you type; the numbers above are the mode's starting point and the range its table describes. In the app the shortcut label is Railway, 921 - 925 MHz.

What OnAir shows

Base stations: ARFCN, BSIC, cell identity, location area, operator code, channel lists; band scan; receive only.

The mode's own tab has these screens: Cells, Channel lists, Carriers, Log. The other tabs (Overview, Receiver, Scan, History) are described on the Main window page.

Tips and caveats

• Checked with generated signals and impairments; recordings of real signals welcome.
• Which radio: Usually yes for narrowband signals: an RTL-SDR tunes roughly 24 MHz to 1.7 GHz at up to about 2.4 Msps. Wide signals such as TV channels need a faster radio, and OnAir says next to the source what the selected radio can do.
• Try it without a radio: most modes include a built-in synthetic test signal, so you can open the screen and try the controls first.
• Receiving and the law: OnAir only reads the public broadcast information of cells and base stations, and does not decrypt or follow any user traffic. Check the rules where you live. See Legal.

Related pages

• All modes, Cellular & rail
• Supported radios, Troubleshooting, FAQ
• More in Cellular & rail: Cell towers, 5G NR cells, NB-IoT cells, LBJ