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Hi
I noticed at several times that in some cases the handsets with a combined attach are unreachable even with a good network coverage;I noticed also that some BVCI disappears from both BSC and SGSN database but after lock/unlock it’s ok and the Paging problem disappear.
the questions are :
1.is this statement wrong ?2.could a Gb congestion in a BSC causes a paging issue?
you need detailed traces investigation about this issue… Perhaps an NSS engineer could help?
What vendor are you working with
i´ve seen the same problem in Ericsson RAN + Ericsson Core and
Ericsson RAN + Huawei Core and still can´t find the reason for this issue
I think that its a RAN + MS problem in my case
what did you ment whith lock and unlock ?I ment Lock an unlock the NSVCI form SGSN or BSC in order to synchronise the BVCIs.
concerning the vendors the CorePS is from Siemense and RAN is from E///i found something but i’m not sure:
if a cell (or a site)goes down and once the issue fixed become up in our case there no synchro between the BSC and the SGSN at the BVCI level.I have enabled EDGE with A-Bis over satellite. With 2 DATA TS on the airinterface it works fine but when I give 3 or more TS in a carrier as PDTCH then data transfer stops. Any idea?
It’s strange that it stops. Your Abis satellite is certainly not 2Mb/s, you’re just buying a certain share, equal to 640kb/s or so.
And 2TS in Edge on the radio interface are using up to 9 Abis ts (9 * 64kb/s). If you add a 3rd one, it’s probable the Abis link becomes congested, therefore reducing throughput on PDCH.
But why does it stop, i don’t know. Probably vendor-dependent.
Hi we have enabled Gs interface in our network. we are using Nokia RAN, Nokia MSS,HLR and Huawei SGSN. After the implementation it is observed that the SDCCH attempts have become very high (40-50) higher and the attempts are high on MOC. Furtrher analysis shows the MOC attemts are high due to Loaction update resulting in high SDCCH blocking
My question: How Gs interface can cause can increase in location update attempts?? Please let me know if anyone has noticed such a thing or resolved an issue
sanyam,
the activation of the Gs interface also means that there are combined LA/RA updates.
3GPP 23.060
“Co-ordination of LA update and RA update, including periodic updates, thus saving radio resources. A combined RA / LA update is sent from the MS to the SGSN. The SGSN forwards the LA update to the VLR.”“When the MS enters a new RA in network operation mode I, the MS sends a Routeing Area Update Request message to the SGSN, as described in clause “Combined RA / LA Update Procedure”. The LA update is included in the RA update.”
“A routeing area update takes place when a GPRS-attached MS detects that it has entered a new RA, when the periodic RA update timer has expired, or when the MS has to indicate new access capabilities to the network”
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Therefore,
check your RA Code and RA Colour design (I recommend 1 RA code and 1 RA colour per LAC)
(example of such settings : all cells in your network are set with RA code = 1 and RA colour = 1. It is strange, but actually each routing area is different from LAC to LAC, because the RA id is defined by the association LAC + RAC, which is here unique.)cheers
pixThanks Pix, Really appreciate your prompt response and help.
I shall get the same checked. However just to add to the description of the problem, These high SD attempts are observed randomly in any cell, in any bts, in any bsc at any random time.There are 20 Bscs integrated to Nokia MSS,HLR and Huwaie SGSN.The attempts at random increase 40-50 times above normal for just a few hour/s and then subside again. (For e.g in normal case if the SD attempts were around 4000 they all of a sudden shoot up to 200000 for any hour. We have disable NMO in one of the BSCs and have observed the blocking and this random behaviour has subsided significantly.Prior to implementation ogf Gs interface this scenario was not observed.
thanks and regards
SanyamSanyam,
that is an important information you just wrote… it would tend to prove that the problem comes from a “bug” ? Anything randomly happening is probably due to sw bug…
So far I have little feedback about Gs-interface troubleshooting, the only thing I can do is point what you should be looking at… If you have any result, please let me know 🙂
regards
pixCan anybody explain the following parameters are same
1. Packet data call drop is same as DL_TBF_Failure_Rate
2. Packet Data CSSR is same as DL_TBF_Success_Rate
Hi,
in cases with no Gs Interface, is it good to have one RA code per LAC? In our network there is a situation: 1 LAC in 2 BSC and one RA code per BSC. Could that be the reason of “subscriber unreachable” sometimes when MS is involved in GPRS and in transfer mode?
Regards,
Rex.hello,
Without Gs interface, a subscriber in transfer mode is never reachable, because it doesn’t hear the paging request that is broadcasted on the BCCH.
Some phones are able to hear it, but they are rare.So you see, that’s the whole point of the Gs interface 🙂
For Gs implementation , i have heard that some phones are not able tu support it, here more explanation: when MS is GPRS attached and SGSN perform detach (after detach timer expiry), when mobile goes from one lac/rac and another he still make it on GPRS channel but no connection so he will move to another location and the network still have the old location. Anyone has more details about this phones (not 3gpp standardized) and procedure.
Hi pix,peter
ya i think its right there are class A and class B mobile in market and i think class b will not support this feature.
and pix in two of my msc gprs traffic is high compare to other msc and paging sucess is very poor in that msc then by gs interface wiii it help to improve psr?
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