SDCCH/4 and SDCCH/8

Hi,
Thanks for the reply. But control related signalling during TCH is
done via FACCH and SACCH right? So, if I am getting you right, SDCCH/8
will use the whole of TCH transmission slot on its behalf. Is it?
Making it similar to a BCCH+TCH combination where TS0 is used for BCCH
always in a TCH frame!

Please do help!!

Thanks in advance.

--
Jagadeesh

jagz wrote:
> Hi,
> Thanks for the reply. But control related signalling during TCH is
> done via FACCH and SACCH right? So, if I am getting you right, SDCCH/8
> will use the whole of TCH transmission slot on its behalf. Is it?
> Making it similar to a BCCH+TCH combination where TS0 is used for BCCH
> always in a TCH frame!
>
> Please do help!!
>
> Thanks in advance.
>
> --
> Jagadeesh
>

Hi, on SDCCH channel uses 1/8th of a single timeslot. The terms SDCCH/8
and SDCCH/4 just describe different configurations (as explained already
earlier, SDCCH/4 means the case where SDCCH is combined with BCCH/CCCH
in timeslot 0 ; in this case, half of the timeslot is reserved for
BCCH/CCCH and on the other half timeslot, 4 SDCCH channels are allocated
; SDCCH/8 means a full timeslot is allocated for SDCCH, and in this case
it can accomodate 8 SDCCH channels).

There is no FACCH when SDCCH is used (SACCH does exist, though). When a
connection in TCH is used (such as speech call or CS data), FACCH is
just a logical channel, using the allocated TCH for sending signalling
messages).

In case this didn't make it clear enough, please take a look at 3GPP TS
05.02 (http://www.3gpp.org/ftp/Specs/latest.../0502-8b0.zip).

I hope this clarifies the issue.

Regards,
Antti