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coursekec
2010-06-12, 09:13 PM
Under which conditions are SDCCH/4 and SDCCH/8 implemented ? what are the advantages and disadvantages in both the cases ?

RF engineer
2010-06-12, 10:37 PM
Under which conditions are SDCCH/4 and SDCCH/8 implemented ? what are the advantages and disadvantages in both the cases ?

There two type of common control channel configuration which you see it in cell paraMeter in your OMC which call combined-BCCH in this type you have to configure SDCCH/4 or if you configure a cell with non combinedBCCH you will have to use SDCCH/8 advantage of SDCCH/4 is that if you have TRX configuration 1or 2 TRX you can use combined bcch and diadvantage is more than advantage because you will have few resource for location update and paging.

coursekec
2010-06-14, 08:32 PM
thanks for the reply..but i have one more confusion..how many subscribers can get access to SDCCH under SDCCH/4 and under SDCCH/8 configuration..?

RF engineer
2010-06-15, 12:09 AM
thanks for the reply..but i have one more confusion..how many subscribers can get access to SDCCH under SDCCH/4 and under SDCCH/8 configuration..?
just simply use erlang B table and take GOS 0.5 % and check for 8 and 4 it gives you Erlang and take 0.025 mERl/sub it gives you number of sub i leave the calculation for you.
BR
RF

coursekec
2010-06-15, 08:34 PM
thanks RF engineer,

I have calculated the no of subscribers supported by SDCCH/4 in the following fashion

no of circuits (N)= 4
Probability of loss (blocking probability) =0.5% or 0.005, from erlang table total offered traffic (erlangs) = 0.702, erlangs per subscriber = 0.025 Erl/sub,
Total subscriber supported = 0.702/ 0.025 = 28.08
Is this correct..??

RF engineer
2010-06-16, 02:44 AM
thanks RF engineer,

I have calculated the no of subscribers supported by SDCCH/4 in the following fashion

no of circuits (N)= 4
Probability of loss (blocking probability) =0.5% or 0.005, from erlang table total offered traffic (erlangs) = 0.702, erlangs per subscriber = 0.025 Erl/sub,
Total subscriber supported = 0.702/ 0.025 = 28.08
Is this correct..??

it is Correct

s52d
2010-06-18, 04:26 AM
SImple designing rule:
1. In big location area you have to use SDCCH/8 only in order to have paging capacity.
2. in smaller LA you do:
4 SDCCH for one TRX cell
12 SDCCH for two to four TRX cells
20 SDCCH for bigger cells.

Observe statistics: if needed, increase. If smaller number can do, decrease.
If you use features to lower SDCCH congestion like direct assignment to TCH
or dynamic reconfiguration of TCH to SDCCH/8, then some congestion might be allowed.

I've seen 4 TRX cells working fine with 4 SDCCH and 31 TCH.

As ratio of LAU/SMS/calls is different, not to mention impact of national roamning,
calculations are just initial guess.


BR

hakimgsm
2010-08-04, 06:11 AM
Hi
The following doc is very useful to known more the SDCCH .
Best regards.






SImple designing rule:
1. In big location area you have to use SDCCH/8 only in order to have paging capacity.
2. in smaller LA you do:
4 SDCCH for one TRX cell
12 SDCCH for two to four TRX cells
20 SDCCH for bigger cells.

Observe statistics: if needed, increase. If smaller number can do, decrease.
If you use features to lower SDCCH congestion like direct assignment to TCH
or dynamic reconfiguration of TCH to SDCCH/8, then some congestion might be allowed.

I've seen 4 TRX cells working fine with 4 SDCCH and 31 TCH.

As ratio of LAU/SMS/calls is different, not to mention impact of national roamning,
calculations are just initial guess.


BR

jitendra1020
2010-08-04, 10:24 AM
Hi,
share password

hakimgsm
2010-08-04, 04:35 PM
Password : mobilis

Good luck

Alim
2010-08-04, 11:51 PM
erlang_B.exe
plz add rep

Dikas
2010-08-24, 03:04 PM
erlang_B.exe
plz add rep

plz reupload to 4shared

ritgail
2011-05-14, 02:31 PM
erlang_B.exe
plz add rep


Password please...

saintdeji@yahoo.com
2011-05-15, 05:43 AM
Hi guys, i've learnt alot from ur post. i cant seem to download the attached file. Can u kindly guide me through?

haq_enam
2011-05-16, 12:37 PM
In Huawei system SDCCH can be dynamic... If somehow u need to have more SDCCH that will help to get more sdcch taking from TCH...

f_tito
2011-05-19, 04:08 PM
Hi all, is there any technology that enable dynamic SDCCH allocation? so the BTS or cell can adjust SDCCH from SD/4 to SD/8 or maybe add the TSL for SDCCH

Thanks,

karimos
2011-05-20, 01:05 AM
thanks:handshake:

leelio
2011-05-24, 04:24 PM
Hi all, is there any technology that enable dynamic SDCCH allocation? so the BTS or cell can adjust SDCCH from SD/4 to SD/8 or maybe add the TSL for SDCCH

Thanks,
do you mean sdcch reconfiguration? yes, there is..

ghassen
2011-05-26, 09:48 AM
sdcch 4/8 is emplemented according to the Tch/LU/SMS capacity needed for signaling
for example if you have cell in wich there is too much trafic in SMS you have to consider a high need on SDCCH specially in poor country or near the university compounds
if you have a siemens equipement the sdcch can be dimensionned dynamically if you are using the TCH/SD pool
Good luck

shup7
2011-05-31, 03:19 PM
Hi
The following doc is very useful to known more the SDCCH .
Best regards.


thank you for sharing a good DOC.

Shnize
2011-10-13, 07:09 PM
erlang_B.exe
plz add rep

Hi i am a new member please guide me on how to be able to download the documents attached on the forum like the Erlang B.exe file.