CCCH configuration =2 TDMA

[wael]

Dears
Could you pls send me the |TDMA multi frame when the CCCH configuration =2

[wael]

According to 3GPP TS45.002 the only permitted channel combination for CCCH are:
1)BCCH + CCCH + SCH +FCCH /SDCCH4
2)BCCH + CCCH + SCH +FCCH
3)BCCH + CCCH
Also we can have more than one CCCH in a cell. The Ist or 2nd combinations are mandatory for (Basic) Ist CCCH and its timeslot should be 0 and this combination cannot be repeated.
If we need to have additional CCCHs due to any reason then they should be configured on timeslot 2,4,6 with channel configuration BCCH + CCCH.

This is because the MS cannot listen to the two timeslots simultaneosly (CCCH = PCH + RACH + AGCH). It is the same if you have PBCCH the GPRS attached MS listens to the PBCCH not to normal BCCH.
Actually it's like this:
"Creation of additional BCCH+CCCH is possible but only on the timeslots 2,4 and 6 of C0. The info about the used control channel configuration is sent in the Parameter ‘CCCH_CONF’, which is part of the IE ‘Control Channel description’ sent in the SYS_INFO3 on the BCCH. If more than one BCCH is created for a cell the MSs observe the BCCH on timeslot 0 first and - having detected that there are more than one (from the CCCH_CONF) - select one BCCH/CCCH timeslot for all their CCCH activities on the basis of their CCCH_GROUP. The CCCH_GROUP is calculated from the last three digits of the IMSI and the CCCH configuration"

And according to CCCH-Group MS will listen to CCCH it can be on time slot 0, 2 , 4 or 6.
Now MS without multislot capabilities can't listen to 2 slots on same TDMA frame, that why we need to provide BCCH on the same slot with CCCH.
TDMA frame for all CCCHs is same but timeslots are different

[zhanglw268]

See below diagram:

[wael]

many thanks zanglw ,but i couldnt download the attached image , could you pls send it to my personal mail wa2003elq@hotmail.com

[zhanglw268]

You can do right click on the picture and save it locally.

Attached is the html file I made that you can save for future use freely.

Regards

Zhanglw268