- This topic has 26 replies, 1 voice, and was last updated 13 years, 8 months ago by pix.
15th January 2007 at 14:45 #46430IVKGuest
In our network we have very low Immidiate Assigment Success Rate. All hardware is good. So, where I can find the problem?18th January 2007 at 11:11 #46431yogesh_rfGuest
you please check for:
1.Your CCCH Configuration,whether it is Combined or non combined
2.Check for your A-bis link and Um interface if any problem in these.
bcoz as per my knowledge Immediate Assignment command relates to SDCCH Assignment, also check for T3101.
would appreciate your feedback.
Yogesh_rf19th January 2007 at 06:35 #46432ivkGuest
Thank you, Yogesh_rf.
I will try to make this change. And I have one more quetion.
Relation between Immediate Assignment and interference?19th January 2007 at 07:19 #46433yogesh_rfGuest
actually Interference relates with your Um Interface, which relates to Assignment, so it can also be the cause, you also check for Phantom RACH,if the site is having very low traffic, give me your mail id, i will send you a doc. regarding call flow procedures step by step, you can understand the things in a better way
Yogesh_rf19th January 2007 at 08:46 #46434ivkGuest
Thank you again yogesh_rf.
Best regards,20th January 2007 at 12:38 #46435TufailGuest
Dear I am a bit confused as the difference b/w TCH blocknig and TCH conjestion.
I wanna know abt T200 and N200 Timer. do u have any relevant Doc available. kindly send it to me at firstname.lastname@example.org.
Tufail24th January 2007 at 14:06 #46436treejarGuest
we can say that it is the same , but there is a light difference. a blocking can be or is with a congestion but a TCH congestion doesn’t generate TCH blocking .3rd June 2007 at 18:36 #46437Shady76Guest
Can anyone suggest a possible value for T3101 for a network with Low immediate assignment sucess rate. My current value if 3 sec.
Shady4th June 2007 at 06:18 #46438Rajiv GujralGuest
Timer t3101 is the time the network waits after sending the IMMEDIATE ASSIGNMENT or IMMEDIATE ASSIGNMENT EXTENDED message until the main signalling link is established before releasing the newly allocated channels. The value for this Timer can be between 50ms – 1sec. It is vendor dependent. The current value of this in ur network is 3sec, that is quite high but it will not effect ur networks Low Immediate Assignment Success Rate but it may increase the call set up time in the network.
To increase the Immediate Assignment Seccess Rate firstly find the bad cells and check whether whole site or single single cell in the sites have problem. If the problem is in whole site then it regards to hardware failure or points to Media. Else for other thngs check ur Frequency Plan Co BCCH Co BSIC conflicts, the Max TA from which ur cell is taking the call, Uplink and Downlick Interference and Link Budget.
Hopefully this will help u out.
Rajiv Gujral4th June 2007 at 07:51 #46439PixGuest
3 seconds is the default value for alc’tel network, you should also check that the T_IA is lower than T3101 (T_IA = 2.5s default)
So if your parameters are correct, you have to find the cause for the failure : SDCCH congestion ? assignment failure due to radio ? assignment failure due to BSS ?
In alc systems, the normal sdcch assignment failure rate is about 10% to 20% in rural areas, and about 5% to 10% in urban areas.
Regards,4th June 2007 at 08:57 #46440NarChaiGuest
The SDCCH timer will effect to number of immediate assignment sucess rate. but
If T3101 expire you will see the percentage MSs access SDCH low also.5th June 2007 at 09:26 #46441raghuGuest
where is this timer T_IA? i.e on which network object?5th June 2007 at 12:34 #46442narchaiGuest
would you please specify the SDCCH times
thanks5th June 2007 at 12:35 #46443asoGuest
would you please specify the SDCCH timers6th June 2007 at 17:45 #46444NarChaiGuest
T3101 = the timer that supervision of the Immediate Assingment procedure