gr-gsm Tools

SDR & RF HardwareReady to RunLocation: Conda env (telcosec-sdr)

Command Line Execution

Run this command in the TelcoChisel terminal to launch or execute the tool:

gr-gsm Tools Command
grgsm_livemon

Detailed Technical Overview

gr-gsm is a set of blocks and tools for receiving, decoding, and analyzing the GSM air interface (2G). Built on GNU Radio, it decodes Downlink packets and forwards GSMTAP frames to Wireshark for analysis.

Configuration & Usage Guide

To initialize and configure gr-gsm Tools for telecom security audits, follow these steps:

  1. 1Activate the SDR workspace: conda activate telcosec-sdr
  2. 2Start the graphical live monitor: grgsm_livemon -f 945.2M -g 40
  3. 3Open Wireshark and filter by 'gsmtap' to view decoded GSM frames in real time.

Troubleshooting & Security Audits

gr-gsm Tools Audit Warning
Ensure you have calibrated your RTL-SDR or HackRF oscillator frequency offset, otherwise gr-gsm will fail to lock onto the BCCH carrier frequency.
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Frequently Asked Questions

Which bands can gr-gsm monitor?

It can monitor any GSM band (GSM850, GSM900, DCS1800, PCS1900) supported by your RF front-end.

Does gr-gsm decode encrypted traffic?

No, gr-gsm decodes unencrypted control frames and broadcasts. Decrypting voice or SMS requires session key access.

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