- This topic has 32 replies, 1 voice, and was last updated 13 years, 2 months ago by Promod.
15th May 2007 at 13:48 #46278nachiGuest
Iam having low CSSR due to message failure at assignment level,what could be causing that.On other instances i have High immediate assighnment withiot MS_Seizure.I would appreciate if i can get an explaination on the same.
Possible solutions to counter low CSSR will be appreciated.
Nachi15th May 2007 at 14:35 #46279PixGuest
Low CSSR due to poor assignment success…
First, which assignment ? The SDCCH or the TCH ?
Possible low CSSR (depending on your CSSR formula !!)
poor radio conditions on BCCH
poor radio conditions on SDCCH
poor radio conditions on TCH (unable to access the ts TCH)
and hardware failure : abis, combiner, tre, crossed tre, crossed sectors, etc…
regarding IMMEDIATE ASSIGNMENT, the possible failure cause is mostly SDCCH congestion. Check the SDCCH traffic and resources usage, you might notice you’re exceeding the offered traffic.
Regards,16th May 2007 at 06:18 #46280Rajiv GujralGuest
In my pointof view Immediate Assignment will never be due to SDCCH Congestion. SDCCH congestion may cause SDCCH Allocation failure. Poor SDCCH assignment success rate can be due to CO BCCH CO BSIC conflicts, poor quality, VSWR and other h/w failure.16th May 2007 at 06:22 #46281Rajiv GujralGuest
The CSSR in my network is ~90 in most of the cells even when there is no SDCCH assignment failure, no TCH assignment failure, no allocation failures, no blocking on SD adn TCH. Can u suggest me at which end(MSC, BSC, BTS) i will look to improve my CSSR.
Regards16th May 2007 at 19:08 #46282adeelGuest
1.in Tems Investigation report, whats is the definition of call attempt, call setup, call established, and call ended?
2.i have seen that sometimes number of call established in not equal to no. of calls ended, why?
Kindly help me25th July 2007 at 22:27 #46283akefaGuest
I think your 90% CSSRs are due to the different between the sdcch attemps and sdcch assignment. If you type the formula of the CSSR used in your network, things will be more clear.11th December 2007 at 12:35 #46284lycanGuest
need help on how to solve Sdcch Assign Failures… thanks for all the help.14th December 2007 at 14:30 #46285EUGE2007Guest
Hi guys, how can one effectively push traffic to 1800Mhz band if the 900Mhz is congested in HCS systems.15th December 2007 at 09:05 #46286pixGuest
i don’t know the E/// system, yet I believe they are using a kind of “capture” handover from 900 to 1800. Check their handover types.19th December 2007 at 09:11 #46287FahimGuest
If there is congestion in A channels and call assignment failure occures due to that – then will it be considered as call drop in radio ?19th December 2007 at 09:16 #46288pixGuest
no the call hasn’t been established yet, so this is a call setup failure, and more exactly, it is a TCH assignment failure.
pix20th December 2007 at 11:30 #46289FahimGuest
U have made my conception clearer – thnx. Can you tell me any other KPI in A-channels which might affect cal drop or CSSR in radio ?20th December 2007 at 12:22 #46290pixGuest
every kind of failures on the a interface would lead to a call drop or a call setup failure, isn’t it ?
but it’s a bit tedious to list all of them.. i’m not going to do it 🙂21st January 2008 at 06:34 #46291mohit kumar guptaGuest
what is sd drope & cssr ?22nd January 2008 at 04:05 #46292pixGuest
sdcch drop : drop during the sdcch phase (could be for LU, call setup, SMS, …)
CSSR : call setup success rate : failure or drop during any phase between a channel request and the succesful establishment of a TCH. It includes the SDCCH drops, TCH assignment failures, sometimes also, the SDCCH assignment failures . It is vendor dependent.