- This topic has 3 replies, 1 voice, and was last updated 11 years, 1 month ago by Pan.
31st July 2009 at 09:17 #58244slimoskaranosGuest
Some measurements done with SwissQual show the existence in the network of several fails in call set up due to location update
My question is :
Is Cell reselection allowed in Call set up or it’s due do the fact that there’s probably a repetitive fail in according
a SDCCH and thus the mobile is still in idle mode so that he can change the cell???
Normally, we can say that the mobile in engaged to establish its call in the desired and fixed cell from the begininig even with the unreachable success in call set up.No?
What’s your opignon??31st July 2009 at 16:30 #58245PixGuest
what an impressive name !
when the MS performs a Location Update, it first makes a “call setup”, in order to get a SDCCH. I wouldn’t actually call it a call setup, but in SwissQual I assume they are making this assumption ?
Anyway, the MS required a SDCCH channel, in order to perform the location update.
The failure means that either:
SDCCH has failed (radio fail ?)
SDCCH was congested (MS couldn’t get a SDCCH because BSC detects a SDCCH congestion)
Location Update was failed (hte MS gets the SDCCH, but the Loc Upd was rejected by the NSS.
I would say that the last option is probably the one which is indicated by SwissQual.
Could you look at layer 3 traces ? Check the Location Update Request (in the Connection Request, isn’t it ?)
And check the content of the Location Reject message.
Pix3rd August 2009 at 07:09 #58246slimos this timeGuest
Oh Pix , yes it’s an impressive name 🙂
No, it’s a real call set up done with SwissQual (an automatic scenario ) but in certain cases, in indicates a fail in call set up with cause C3.50 .In code description SwissQual indicates this message:Failed, No Setup -> Location Updating3rd August 2009 at 08:13 #58247PanGuest
Let call setup fail. But Location update? Fail or no? Any additional info about cause C3.50? For the best if you will indicate the standard cause value for Call setup and Location rejection (if any).
It is possible the following:
1)Call setup (CM_Service_Request) and rejection this message with cause Imsi unknown in VLR.
2)In general case the majority of mobiles makes subsequent Location Update message with ‘follow on proceed’ indicator and without subscriber notice.
3) After succesful Location Updating procedure the Call Setup attempt follows in a general way.