Re: [Openbts-discuss] how to know a burst is belong to MAC/RLC control block or MAC/RLC data block

[Alexander C. <ale...@gm...>]

John,

PTCCH is a separate from other channels by multi-frame mapping.

If I understand correctly, PACCH is just an other logical channels and
is is separate from other logical channels with a different USF. But I
have to check the standard here, as I'm not sure I recall correctly.

On Thu, Oct 27, 2011 at 12:27, John Wu <jw...@gm...> wrote:
> Alexander,
> BTS can specify the MS using CS-1,2,3,4 in the PTCH, however in PACCH or
> PTCCH the channel
> should always be encoded with CS-1. So if the BTS specify one MS using CS-2
> but the MS still can
> use CS-1 to send a control message. Then BTS should be able to distinguish
> which
> channel conding scheme the received burst used.
>
> On Thu, Oct 27, 2011 at 4:18 PM, Alexander Chemeris
> <ale...@gm...> wrote:
>>
>> John,
>>
>> If you (BTS) haven't said it to be CS-2/3/4, then it's CS-1, so again
>> you always know CS. I think the logic is that simple.
>>
>> On Thu, Oct 27, 2011 at 11:55, John Wu <jw...@gm...> wrote:
>> > Alexander Thanks,
>> > I don't know if I understand gsm 04.60 correctly. I think even on BTS
>> > side
>> > you are not able to
>> > know which cs you received. for in uplink TBF, MS may send some control
>> > message which is
>> > fixed coded with CS1 and you do not know when will the MS send a control
>> > message.
>> >
>> > On Thu, Oct 27, 2011 at 3:43 PM, Alexander Chemeris
>> > <ale...@gm...> wrote:
>> >>
>> >> John,
>> >>
>> >> As Sylvain already mentioned, coding scheme is encoded in stealing
>> >> bits of Normal Bursts, transmitted over PDCH. Each RLC/MAC consist of
>> >> 4 NB's and thus you have 8 stealing bits pattern for each CS. Check
>> >> GSM 05.03 and read gprsdecode sources, it helps.
>> >>
>> >> Also note, that Uplink Coding Scheme is controlled by BTS and thus if
>> >> you're on the BTS side you always know which CS you receive.
>> >>
>> >> Are you implementing GPRS for some commercial stack?
>> >>
>> >> On Thu, Oct 27, 2011 at 11:06, John Wu <jw...@gm...> wrote:
>> >> > Hi all,
>> >> > I want to know how to know GPRS channel coding. GPRS using PDCH, both
>> >> > MAC/RLC data block and MAC/RLC control block is
>> >> > transmitted on PDCH,  although there is PACCH, PTCH, PTCCH and so on
>> >> > it
>> >> > still PDCH. then the MAC/RLC control block is coded
>> >> > with cs-1 channel coding scheme and MAC/RLC data block may be coded
>> >> > with
>> >> > other channel coding scheme. so when received a
>> >> > burst how to know what kind of MAC/RLC block it belong to and which
>> >> > channel
>> >> > coding scheme it used?
>> >> >
>> >> > Thanks!
>> >> >
>> >> >
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>> >> >
>> >>
>> >>
>> >>
>> >> --
>> >> Regards,
>> >> Alexander Chemeris.
>> >
>> >
>>
>>
>>
>> --
>> Regards,
>> Alexander Chemeris.
>
>



-- 
Regards,
Alexander Chemeris.