NW Release

Pix, that´s what I was trying to say.

The handshaking in that cases is this:

sdcch:authentication request/response
sdcch:ciphering mode cmd/cmp
sdcch:setup (ul)
sdcch:call proceeding (dl)
sdcch:assignment cmd (dl)
tch:sabm (ul)
tch:UA (dl)
tch:assignment complete (ul)
tch:disconnect (dl) -this is the Network Release I mentioned –

It’s almost the same you mentioned, but there’s no Alerting msg.

In that cases, there’s only 20seg between the Ch. Request and Disconnect.

BR.

Pix,

The drive test was performed using a 90sec. call, and after that, a redial (almost 100 Call Setups sequences).

This problem was found on 26% of the Call Setups, in different cells, but the same LA.

In that cases, the handshiking was as follows:

UL Channel Request
DL Immediate Assignment
UL SABM-CMD
DL Ciphering Mode Command
UL Ciphering Mode Complete
UL Setup
DL Identity Request
UL Identity Response
DL Call Proceeding
DL Assignment Command
UL Assignment Complete
UL SABM-CMD
DL Disconnect (20 sec. after Ch. Req.)
UL Release (Call End – NW Initiated Release)
DL Release Complete
DL Channel Release
UL DISC-CMD
DL UA-RSP

So, there is an Assignment Complete msg, but there’s no Alerting msg.

We ask MSC administrators in order to ask for a signaling trace.

Dear Ms! Perhaps you must to search your Alert on destination side? What kind of call is it? MOC or MMC? Is destination number within PLMN or PSTN? In latter case: Is your PSTN completely digital network or there are many analog exchanges in PSTN? Tell your NSS engineer to analyse the trace record on E-interface between your MSC and PSTN if destination number is located within PSTN.

Pan & Pix,

The destination number is within PSTN.

Pix, the Assignment Complete msg is as follows:
————————
MS2
Assignment Complete
Time: 12:21:16.54
Frame number: 2194570
Skip indicator : 0
Protocol discriminator : (6) Radio resources management messages
Message type : 41
RR cause
Value : (0) Normal event
————————

There’s no Alerting msg in this cases, and this is the main problem (after the Assignment, we receive a Relesease from the Network).

The Disconnect msg from the Networks is as follows:

———————–
Transaction identifier : 8
Protocol discriminator : (3) Call control; call related SS messages
Message type : 37
Cause
Coding standard : (3) Standard defined for the GSM PLMNS
Location : (2) public network serving the local user
cause value : (31) Normal, unspecified
———————–

Tomorrow we’re going to perform a Drive Test, but in this case it’ll be complemented with a MSS trace, so I’ll keep you posted.

BR.

Hi all,

Finally, the problem was fixed.

We talked with core administrators, and the problem was a malfunction in a SS7 signaling E1.

When the mobile sent the Setup msg, there was no response from de network, because of lack of signaling frames.

Best Regards,

ms

MS1 call MS2 (same network).
MS1 has:
Channel Request
Immediate Assignment
Setup
Call Proceeding
Assignment Command
Assignment Complete
Alerting (DL)
Call Setup
Disconnect
(Setup time~18.5s)
while MS2 has no Call Attemp (no Channel Request, just Cell Reselection).
In this case, call failed.
Anyone let me know the cause and solution.
Disconnect msg:
Time: 09:27:11.98
Frame number: 372727

MsgCtrlOperation :
Transaction identifier : 8
Protocol discriminator : (3) Call control; call related SS messages
Message type : 37
Cause
Coding standard : (3) Standard defined for the GSM PLMNS
Location : (0) user
cause value : (16) Normal call clearing

Datalink Failure
DL Event: N200_Timeout
SAPI: 0