- This topic has 16 replies, 1 voice, and was last updated 1 year, 8 months ago by sudip.
14th December 2009 at 11:04 #60179LexaGuest
There are a lot of complains from our subscribers regarding the quality of network. For example, the indicator of GSM coverage is full, but nobody can’t call to this subscriber.
It is possible to find paging message in protocol analyzer, but there is no response on it.
The situation looks like subscribe is detached, but MS is on.
Any suggestions?14th December 2009 at 12:24 #60180ZanduGuest
Plese switch off and switch on the MS and then check.
1>replace the SIM14th December 2009 at 14:17 #60181PixGuest
if the paging message is going through, then it means the MS is attached… So it probably isn’t attached, and we must assume you have seen the paging request while dreaming 🙂
Is there a cell parameter to autorize “IMSI attach” in the cells ? In Alcatel, it is called “ATTACH”.
Does it happen to only one MS, or to many MS ?
If this MS (MS 1) calls someone, does it work ? if few minutes later you try to call that MS (MS 1), can you go through ?
-pix15th December 2009 at 13:16 #60182LexaGuest
thanks for your interest in my problem. The situation happens to many MS and I think it take place in whole our network.
“If this MS (MS 1) calls someone, does it work ? if few minutes later you try to call that MS (MS 1), can you go through ?”
If MS1 calls to someone than the call is successful. And if someone calls to MS1 the call is successful.
The vendor of our equipment is Ericsson.15th December 2009 at 13:26 #60183LexaGuest
regarding your question of “IMSI attach”. Here is the description of this parameter for Ericsson equipment “Attach and detach allowed”.
If this parameter is “NO” then “MSs in the cell are not allowed to apply International Mobile Subscriber Identity (IMSI) attach and detach.”
If “YES” – “MSs in the cell must apply IMSI attach and detach.”
In my previous post I’ve made mistake. Instead “And if someone calls to MS1 the call is successful.” you should read “And if someone calls to MS1 several minutes later then the call is successful.”15th December 2009 at 19:58 #60184PixGuest
You perfectly answered my questions 🙂
So let me rephrase :
1/ the MS1 canot be reached, unless it made a call before.
–> this is typical from MS that is not attached.
2/ there is a attach/detach parameter in ericsson
… is it set to YES or to NO ???
If it is yes, then the problem comes from the MSC/VLR : the IMSI detach timer is too early ! it is a specific timer from VLR, I’m not talking about the parameter you described, which is in the BSS.
Check that the VLR parameter is >> than the T3212.
What is the value of T3212 in your cells ?
pix16th December 2009 at 10:19 #60185LexaGuest
I think that we defined the problem. First of all, the T3212 has two meanings in our network: 4 hours for urban area and 6 hours for rural area. Several weeks ago T3212 was equal for both areas – 4 hours.
There are two parameters on MSC which have relation to LU:
“BTDM=btdm Base time duration in minutes. The base time must be as long as the longest periodic location
updating time in the interworking BSC’s.”
“GTDM=gtdm Guard time duration in minutes. The guard time is used to prevent unnecessary marking of MS
implicit detached, for example if the system clocks are not
synchronized in the MS and in the MSC/VLR.”
Previous meaning of BTDM was 4 hours. Now we’ve changed it and hope it will change the situation. We’ll see…
Thanks for your advices. 🙂16th December 2009 at 15:47 #60186PixGuest
If I’m right, then I’m like the Dark Knight of GSM
(except I don’t have much hair on my chest, and my car barely reaches 110km/h)
(it does have a weird smell, though, that scares dogs away)25th December 2009 at 14:54 #60187KamalGuest
By d way,lexa GS was on..? Paging is done via sgsn or msc only..?25th December 2009 at 16:15 #60188C300GGuest
If it’s mass-probles, check PAGING channels statistics on problem LAC. Is thre enough paging channels? No SDCCH overloads?7th May 2010 at 08:51 #60189SantanuGuest
There is a Paging response problem in one MSC with MOTOROLA BSC’s. The paging response fail is about 35%. Suddenly it happaned. What can be the cause??
Please help me…1st February 2011 at 07:30 #60190AyatGuest
in our network , in some LAC we have paging sucesss rate(%) without repaing 83% and with repaing (paging for 2 nd time ) 84% paging timer is 6 sec.
so i have no idea about this fail except the MS ia battery less or out of coavarge .
Could you help me
and give me hint how i can start5th February 2011 at 10:43 #60191SantanuGuest
the paging if degraded then just check the paging req first from MSC if that increased??? if not then check the MSC BSC signalling links if those are congested then paging will be discarded…26th January 2014 at 17:05 #60192AlyGuest
We are facing the same problem as Lexa in our network, would appreciate any help or guidelines. Our System is Huawei MSOFTX3000.27th January 2014 at 11:22 #60193ayatGuest
i will do