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

[John Wu <jw...@gm...>]

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.
>