gr-ale

gr-ale is a MIL-STD-188-141a (ALE 2G) decoding block for GNU Radio.

Usage

The block accepts float input from a USB demod sampled at 8000Hz and outputs decoded data to stdout. It is also capable of recording voice traffic after a 3-step ALE handshake is detected for a preconfigured period of time.

Known Problems

Incomplete support of ALE protocol features, currently only sounding and call establishment are decoded.

Getting Help and Reporting Bugs

Please contact [email protected] or via GitHub issues.

Installation from Source

$ git clone https://github.com/HeroesLament/gr-ale.git gr-ale.git
$ cd gr-ale.git
$ mkdir build
$ cd build
$ cmake ..
$ make
$ sudo make install

There is a nice Python multi-channel ALE decoder under the examples/ directory. On my machine (six-core AMD bulldozer), it can decode ~22 channels before librtlsdr starts complaining about overruns.

Credits and License

gr-ale is written by Milen Rangelov ([email protected]) and licensed under the GNU General Public License.

Significant portions of the source code were based on the LinuxALE project (under GNU License):

• Copyright (C) 2000 - 2001
  • Charles Brain ([email protected])
  • Ilkka Toivanen ([email protected])

This project includes a snapshot of xmlrpc-c, a lightweight RPC library based on XML and HTTP. xmlrpc-c is used under its respective license:

• For more information about xmlrpc-c, visit their GitHub mirror.