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apo7
2009-02-08, 04:40 PM
Hi,

Does anyone know what's the reason for the TEMS to give error message "Data Link Failure"? After this message there's a call drop or handover failure. :L

Thanks.

mrieza
2009-02-08, 11:50 PM
Hi,

Does anyone know what's the reason for the TEMS to give error message "Data Link Failure"? After this message there's a call drop or handover failure. :L

Thanks.


Hi,

Please refer below answer that I got it from 2nd level support E\\\....

In the logfile, the main event is Dropped Call but with "Datalink failure" event will give you more info when you want to analyse the actual problem. The actual error is Datalink failure :SAPI 0:DL event and N200 timeout.

If you refer to the diagram as per attachmnet, it show datalink is equivalent to Layer 2 in Um interface, meaning between MS and RBS.

For communication between entities in adjacent layers of the same node, it used Service Access Point (SAP). The SAP is identified by its Service Access Point Identifier (SAPI) value. SAPI = 0 for CC, SS, MM and RR signaling. In GSM, one of RR signaling is establishment and release of channels. The procedure is handle by the data link layer.

While the MS requesting for the channel due to handover the T200 timer use to indicates the maximum waiting time for an acknowledgment of an earlier transmitted command frame fom the network. The value of timer T200 for data links is chosen so that re-transmission of a frame can take place at the earliest opportunity. Then N200 timer user to indicate maximum number of re-transmissions depends on the state and channel used. If the MS did not receive an acknowledgment from the network then N200 timer timeout in the phone will generate a datalink failure.

Then later there is a drop call with No service mode as a result a subscriber, who is registered in an MSC/VLR, may be deactivated by the MSC/VLR due to MS does not have any radio contact during a certain period of time.

If you interested to read more about this, please refer to the attached documents.

If you find it useful , please don't forget say thanks and add my reputation :)


Rgds
mrieza

bikplaboi
2009-02-09, 09:25 AM
From my experience, Data Link failure can also be related to a corrup IDB on the RBS/BTS or incorrect configuration of the IDB.

Once that is sorted you should not have any problems.


Thanks:D





Hi,

Does anyone know what's the reason for the TEMS to give error message "Data Link Failure"? After this message there's a call drop or handover failure. :L

Thanks.

kskk
2009-02-18, 09:14 PM
hi

Very good information buddy , can you upload the document on the rapidshare, I need it on urgent bais.

kskk

rnpopt
2009-02-18, 11:25 PM
what should be the value of T200 timer ? I guess its value should be like this:
T200= N200*ny1
where ny1 is a configurable timer on BTS database;as there should be such timer which indicates after what time(duration of the waiting period) re transmission will start.
Am I right?

sonar_bangla
2009-02-18, 11:42 PM
Hi,

Please refer below answer that I got it from 2nd level support E\\\....

In the logfile, the main event is Dropped Call but with "Datalink failure" event will give you more info when you want to analyse the actual problem. The actual error is Datalink failure :SAPI 0:DL event and N200 timeout.

If you refer to the diagram as per attachmnet, it show datalink is equivalent to Layer 2 in Um interface, meaning between MS and RBS.

For communication between entities in adjacent layers of the same node, it used Service Access Point (SAP). The SAP is identified by its Service Access Point Identifier (SAPI) value. SAPI = 0 for CC, SS, MM and RR signaling. In GSM, one of RR signaling is establishment and release of channels. The procedure is handle by the data link layer.

While the MS requesting for the channel due to handover the T200 timer use to indicates the maximum waiting time for an acknowledgment of an earlier transmitted command frame fom the network. The value of timer T200 for data links is chosen so that re-transmission of a frame can take place at the earliest opportunity. Then N200 timer user to indicate maximum number of re-transmissions depends on the state and channel used. If the MS did not receive an acknowledgment from the network then N200 timer timeout in the phone will generate a datalink failure.

Then later there is a drop call with No service mode as a result a subscriber, who is registered in an MSC/VLR, may be deactivated by the MSC/VLR due to MS does not have any radio contact during a certain period of time.

If you interested to read more about this, please refer to the attached documents.

If you find it useful , please don't forget say thanks and add my reputation :)


Rgds
mrieza

hello my frnd u r ryt, when ms or bts/bsc could not communicate in t200 time and resending signals n200 times then it shows datalink failure

justdream
2009-07-15, 07:21 PM
If the MS did not receive an acknowledgment from the network then N200 timer timeout in the phone will generate a datalink failure.

what's the reasons behind that?

Thanks

RF engineer
2009-07-15, 08:26 PM
what's the reasons behind that?

Thanks
Interference and coverage problem
BR
RF

neerajsyal
2009-07-15, 08:36 PM
kindly put it on rapid share thanks in advance

justdream
2009-07-15, 08:52 PM
thanks, so how to solve Radio link failure issue?

RF engineer
2009-07-15, 10:49 PM
Increase T200 or enhance coverage where there are problem of drop.
BR