Hi Harald, I am aware of the complexity of the TETRA system, I just want to implement the physical layer (Layer 1) and if I can also the Layer 2 of the protocol and be able to show that it can be done with GR. I want to create both the RX and TX path using GnuRadio.
I am working on implement the blocks similar to those on Figure 4.1 and 4.2 of EN 300 392-2: V3.4.1 (2010-08).
That shouldn't be such a difficult task.
Best regards, Farhad
________________________________ From: Harald Welte laforge@gnumonks.org To: Farhad Abdolian f.abdolian@yahoo.com Cc: Sylvain Munaut 246tnt@gmail.com; tetra@lists.osmocom.org Sent: Thu, January 27, 2011 5:35:20 PM Subject: Re: TETRA and GRC?
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.