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poncho
2011-12-14, 01:46 AM
Hi,
I have a problem with defining more than 2 SDCCHs on 1 TRX or channell group0. Anytime I increase to 3 or 4 some timeslots get blocked. It is an E******* system and the BSC level parameter MAXNOSDCCHTRX is set to 4. CONFACT is set to 4 for the cells, NUMREQEGPRSBPC is set 2 for the cells. Any idea why I am not able to define more than 2SDCCHs on 1 TRX?
Thank,

louvre
2011-12-14, 02:15 AM
The maximum number of sdcch that you can define on a trx also deopends on your LAPD capacity check the lapd capacity the blocking may be there from there for your case as more than 2 sd then LAPD should be 64 KB LAPD.

student21
2011-12-14, 02:28 AM
hi there,
IMPORTANT:the "thumb-rule" says that 1 SD is to be defined each 2 TRx.
having 1 TRx per cell, it means 8 TS only. consider that 1 TS is default for paging and 1 you need to set as SD... in this case you have 6 TS for traffic... not considering GPRS/EDGE data...
in your case, by setting the number of SD to 3 or 4, it means you leave 3-4 TS for traffic. as far as know it is not possible to set the way you want, since the LOAD on the signaling link would too high to bear.
i do not know E******* param, but in Nokia there is such a thing as LOAD that has to be set.

cheers.
david

P.S.
if you like it, plz give some rep

jitendracellplan
2011-12-14, 04:32 PM
As per thumb rule
Max number of Time slots in 1 trx=2
Max number of Time slots in 1 Sector=32.

jan74
2011-12-14, 06:26 PM
In the past I have allocated an entire TRX(apart from the BCCH timeslot) to SDCCH. This was on a special event site and it worked very well.

maahsan
2011-12-14, 07:39 PM
Hi Jan74

Were you using flex-abis in this case or normal abis without LAPD concentration?


In the past I have allocated an entire TRX(apart from the BCCH timeslot) to SDCCH. This was on a special event site and it worked very well.

student21
2011-12-14, 08:12 PM
As per thumb rule
Max number of Time slots in 1 trx=2
Max number of Time slots in 1 Sector=32.

1 TRx has always 8 TS!!!!
according to this, the second affirmation, one cell cannot have more than 4TRx!!!!
we have cells in the network with 7-8 TRx!!! i managed one network with 12TRx per cell!!!

check your data please.
thx.
david

student21
2011-12-14, 09:02 PM
In the past I have allocated an entire TRX(apart from the BCCH timeslot) to SDCCH. This was on a special event site and it worked very well.

it is a great waste of resources... you say "entire TRx"... of how many???!?!?!
if just one TRx present, it is not possible mate...

aly280779
2011-12-14, 09:15 PM
Hi
for E******* number of SDCCH on the TRX is defined by the license.
BR

khalidsaif82@gmail.com
2011-12-14, 09:37 PM
search about (increase sdcch capacity ) it AXEPARS or exchange property and change it

jan74
2011-12-14, 09:49 PM
it is a great waste of resources... you say "entire TRx"... of how many???!?!?!
if just one TRx present, it is not possible mate...

I had 8 TRX with 7 SDCCHs on the first TRX and 8 spread out on the other ones. Worked a treat.

tapas_k
2012-01-21, 11:36 PM
Hi,
I have a problem with defining more than 2 SDCCHs on 1 TRX or channell group0. Anytime I increase to 3 or 4 some timeslots get blocked. It is an E******* system and the BSC level parameter MAXNOSDCCHTRX is set to 4. CONFACT is set to 4 for the cells, NUMREQEGPRSBPC is set 2 for the cells. Any idea why I am not able to define more than 2SDCCHs on 1 TRX?
Thank,

In E******* system the maximum number of SDCCH depends upon the CONFACT used apart from the BSC parameter MAXNOSDCCHTRX. Pls refer the below table below. As can be seen, with CONFACT set to 4, you can not go beyond 2 SDCCH per TRX, else there will be high singalling load on the LAPD. So for the solution, you will have to change the CONFACT to 3 or 2 depending upon the SDCCH demand in your cell.




Max number of SDCCH/8s per TRX
Max concentration ratio


1

4



2

4



3

3



4

2

icebreaker05
2012-02-03, 04:16 PM
In E******* system the maximum number of SDCCH depends upon the CONFACT used apart from the BSC parameter MAXNOSDCCHTRX. Pls refer the below table below. As can be seen, with CONFACT set to 4, you can not go beyond 2 SDCCH per TRX, else there will be high singalling load on the LAPD. So for the solution, you will have to change the CONFACT to 3 or 2 depending upon the SDCCH demand in your cell.





1

4



2

4



3

3



4

2






Hi TAPAS,

I believed that you're right. But as per my current network scenario, I have 8 TRX on MBC,
CHGR 0 - 4 SDCCH + 2 EDGE TS
CHGR 1 - HOPPING 900
CHGR 2 - HOPPING 1800
TG for CHGR0 and CHGR1 is same and set to CONFACT 4
Will it be possible for me to define another 2 SDCCH to CHGR2(OL)? If I reduce the CONFACT 2 on the TG of GSM 900, I will not be able to 2 NUMREQEGPRSBPC per sector. Could you give me some comments/suggestions?


BR,

hf81
2012-03-06, 08:33 PM
You can put more than one SDCCH on TRX-0 (i.e. CHGR-0) but you want to specify the TSs to be used for SDCCHs

Youssef
2012-05-17, 07:15 AM
You can use sdcch dynamic allocation it's more suitable if you want to increase your sdcch capacity but set high priority to BCCH carrier with 2 TS Max and 8 TS for other TRXs.. Hope it helps