Structure of traffic data in burst_ind messages

Bhaskar11 niceguy108 at gmail.com
Fri Feb 1 20:10:05 UTC 2013


Looks like the problem is because of DTX because the FACCH bursts vanish
during speech and return during pause.

Anyone has experience with DTX?

B.



On Fri, Feb 1, 2013 at 10:42 AM, Bhaskar11 <niceguy108 at gmail.com> wrote:

> Yes, I send the command
> l1ctl_tx_fbsb_req(ms, ms->test_arfcn,
> L1CTL_FBSB_F_FB0 | L1CTL_FBSB_F_SB, 100, 0,
>  app_state.ccch_mode, dbm2rxlev(-85));
> before switching channels.
>
> Now most of the channels stick on for much longer, but a few drop within
> seconds.
>
> But I cannot know for sure if this has "worked" until I can decode and
> recognise some FACCH commands.
>
> On AMR HR I get data like:
>
>   TCH/H (hl=0, hu=0) in FN=1864368 DL SACCH
>   Detected FACCH (hl=1, hu=0) in FN=1864369 DL
>   Detected FACCH (hl=1, hu=0) in FN=1864371 DL
>   Detected FACCH (hl=1, hu=1) in FN=1864373 DL
>   Detected FACCH (hl=1, hu=1) in FN=1864375 DL
>   Detected FACCH (hl=1, hu=1) in FN=1864386 DL
>   Detected FACCH (hl=1, hu=1) in FN=1864388 DL
>   Detected FACCH (hl=1, hu=1) in FN=1864390 DL
>   Detected FACCH (hl=1, hu=1) in FN=1864392 DL
>   TCH/H (hl=0, hu=0) in FN=1864394 DL SACCH
>   Detected FACCH (hl=1, hu=1) in FN=1864395 DL
>   Detected FACCH (hl=1, hu=1) in FN=1864397 DL
>   Detected FACCH (hl=1, hu=1) in FN=1864399 DL
>   Detected FACCH (hl=1, hu=0) in FN=1864401 DL
>   Detected FACCH (hl=1, hu=1) in FN=1864403 DL
>   Detected FACCH (hl=1, hu=0) in FN=1864405 DL
>   Detected FACCH (hl=1, hu=1) in FN=1864408 DL
>   Detected FACCH (hl=1, hu=0) in FN=1864410 DL
>   TCH/H (hl=0, hu=0) in FN=1864420 DL SACCH
>
> which does not look correct because I think the FACCH should be in groups
> of 4.
>
> Any explanations? Suggestions?
>
> B.
>
>
> On Thu, Jan 31, 2013 at 8:38 PM, Pe <oxccoxcc at yandex.ru> wrote:
>
>> Hi, Bhaskar11
>> Did you resolve problem with low snr?
>> Do you make synchronization on SCH before going to TCH, after Assignment
>> Command?
>>
>>
>>
>> --
>> View this message in context:
>> http://baseband-devel.722152.n3.nabble.com/Structure-of-traffic-data-in-burst-ind-messages-tp4025762p4025787.html
>> Sent from the baseband-devel mailing list archive at Nabble.com.
>>
>>
>
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