<html><head><style type="text/css"><!-- DIV {margin:0px;} --></style></head><body><div style="font-family:arial,helvetica,sans-serif;font-size:10pt"><div>Hi Harald,<br>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.<br><br>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). <br></div><div style="font-family: arial,helvetica,sans-serif; font-size: 10pt;"><br>That shouldn't be such a difficult task.<br><br>Best regards,<br>Farhad<br><div style="font-family: arial,helvetica,sans-serif; font-size: 13px;"><font face="Tahoma" size="2"><hr size="1"><b><span style="font-weight: bold;">From:</span></b> Harald Welte <laforge@gnumonks.org><br><b><span style="font-weight:
bold;">To:</span></b> Farhad Abdolian <f.abdolian@yahoo.com><br><b><span style="font-weight: bold;">Cc:</span></b> Sylvain Munaut <246tnt@gmail.com>; tetra@lists.osmocom.org<br><b><span style="font-weight: bold;">Sent:</span></b> Thu, January 27, 2011 5:35:20 PM<br><b><span style="font-weight: bold;">Subject:</span></b> Re: TETRA and GRC?<br></font><br>On Thu, Jan 27, 2011 at 02:25:31AM -0800, Farhad Abdolian wrote:<br>> Hi Sylvain,<br>> Thanks for posting it to the list, I just hit reply, I thought the list is the <br>> main "to" part of the reply, but now I know, I have to put reply-all instead.<br>> <br>> What I am using GR is use the AIR interface of the TETRA in a simple way, I <br>> would like to create a system similar to OpenBTS to handle TETRA. The main <br>> problem I have is I am a pure HW design engineer and my knowledge of Linux, <br>> Python and high level SW is not very strong, but I am
learning.<br><br>Please understand that it is quite a big task to do this. A receive-only<br>implementation like what we have now is relatively simple, but in order<br>to run a full TETRA system, you need to implement all the protocols like LLC,<br>LME, MM, CC and their associated logic, which is a huge task.<br><br>Getting something like a small transmitter goign that continuously transmits<br>a BSCH/BNCH should be a simple task that you can start with. Basically use<br>the same code that we use in conv_enc_test.c to generate the type-5 bits,<br>feed them into the DQPSK modulator and try to see if TETRA handsets can<br>recognize the signal.<br><br>-- <br>- Harald Welte <<a ymailto="mailto:laforge@gnumonks.org" href="mailto:laforge@gnumonks.org">laforge@gnumonks.org</a>> <a href="http://laforge.gnumonks.org/"
target="_blank">http://laforge.gnumonks.org/</a><br>============================================================================<br>"Privacy in residential applications is a desirable marketing option."<br> (ETSI EN 300 175-7 Ch. A6)<br></div></div>
</div><br>
</body></html>