Harald Welte laforge at gnumonks.org
Thu Jan 27 16:35:20 UTC 2011

On Thu, Jan 27, 2011 at 02:25:31AM -0800, Farhad Abdolian wrote:
> Hi Sylvain,
> Thanks for posting it to the list, I just hit reply, I thought the list is the 
> main "to" part of the reply, but now I know, I have to put reply-all instead.
> What I am using GR is use the AIR interface of the TETRA in a simple way, I 
> would like to create a system similar to OpenBTS to handle TETRA. The main 
> problem I have is I am a pure HW design engineer and my knowledge of Linux, 
> Python and high level SW is not very strong, but I am learning.

Please understand that it is quite a big task to do this.  A receive-only
implementation like what we have now is relatively simple, but in order
to run a full TETRA system, you need to implement all the protocols like LLC,
LME, MM, CC and their associated logic, which is a huge task.

Getting something like a small transmitter goign that continuously transmits
a BSCH/BNCH should be a simple task that you can start with.  Basically use
the same code that we use in conv_enc_test.c to generate the type-5 bits,
feed them into the DQPSK modulator and try to see if TETRA handsets can
recognize the signal.

- Harald Welte <laforge at gnumonks.org>           http://laforge.gnumonks.org/
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