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wael
2011-01-12, 05:08 PM
Dears
Could you pls send me the |TDMA multi frame when the CCCH configuration =2

wael
2011-01-12, 11:14 PM
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
2011-01-13, 02:27 AM
See below diagram:

wael
2011-01-13, 04:11 PM
many thanks zanglw ,but i couldnt download the attached image:( , could you pls send it to my personal mail wa2003elq@hotmail.com

zhanglw268
2011-01-13, 07:58 PM
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