Measurement Counter
CM30C:CELL_SD_CALL_DROPS_CALL
Description
After the MS seizes a channel, this measurement provides the number of call drops of the calls with the types of MOC, MTC, emergency call, and call re-establishment on the SDCCH. The causes for the call drops are as follows: the BSC initiates the release procedure after receiving the error indication, connection failure message, or release indication due to due to Um interface failure; the BSC initiates the release procedure after the timer waiting for handover completion expires; the BSC initiates the release procedure due to Abis terrestrial link failure, no MRs from MS for a long time, equipment failure, or forced handover failure.
Unit
Integer number or integer.
Measurement Point
When an SDCCH is seized during a call, and the call type is MOC, MTC, emergency call, or call re-establishment, this counter is measured in the following situations:
1. The BSC receives an ERROR INDICATION message from the BTS because of the abnormal connection on the radio link layer. For details, refer to GSM Rec. 08.58.
2. The BSC receives a CONNECTION FAILURE INDICATION message from the BTS because of link fault or hardware fault on the radio link layer. For details, refer to GSM Rec. 08.58.
3. When receiving a DISC frame on a link layer connection in multi-frame mode, the BTS sends a REL IND message to the BSC. For details, refer to GSM Rec. 08.58.
4. The timer set to wait for an HO CMP message expires during internal intra-cell handover.
5. The timer set to wait for an HO CMP message expires during outgoing internal inter-cell handover.
6. The timer set to wait for an HO CMP message expires during outgoing external inter-cell handover.
7. The timer set to wait for an HO CMP message expires during incoming external inter-cell handover.
8. The BSC does not receive any measurement report within a certain period (by default, five minutes) and sends a CLEAR COMMAND message to the MSC to release the call.
9. The BSC detects a broken RSL and releases all the calls on the RSL.
10. A call drop occurs in any of the following situations: TRX mutual aid; dynamic modification of cell attributes, TRX frequencies, or TRX FH data; dynamic deletion of cells or TRXs; blocking of cells, TRXs, or channels.
11. The timer set to wait for the outgoing BSC handover command expires, or the clear request message is received from the MSC before the timer expires.
12. A call drop occurs because of call assignment failure during the handover.
13. The MSC cannot send a short message because the data configuration prohibits the downlink short messages or because of flow control, and the call is released.
14. A call drop occurs because of software error.
15. A call drop occurs during the emergency handover because of PDCH assignment, or during the handover caused by TRX mutual aid, preemption, or blocking of cells, TRXs, and channels.
This counter is calculated at A1, A2, A3, A4, and A6, as shown in Figure 1, Figure 2, Figure 3, Figure 4, and Figure 5.
A1: Call Drops Due to ERR IND Received in Stable State, Call Drops Due to the ERR IND Received on the TRX in the Underlaid Subcell in Stable State, Call Drops Due to the ERR IND Received on the TRX in the Overlaid Subcell in Stable State |
A2: Call Drops Due to the CONN FAIL IND Received in Stable State, Call Drops Due to the CONN FAIL IND Received on the TRX in the Underlaid Subcell in Stable State, Call Drops Due to the CONN FAIL IND Received on the TRX in the Overlaid Subcell in Stable State |
A3: Call Drops Due to REL IND Received in Stable State, Call Drops Due to the REL IND Received on the TRX in the Underlaid Subcell in Stable State, Call Drops Due to the REL IND Received on the TRX in the Overlaid Subcell in Stable State |
A4: Call Drops Due to No MRs from MS for a Long Time, Call Drops Due to No MR from the MS on the TRX in the Underlaid Subcell, Call Drops Due to No MR from the MS on the TRX in the Overlaid Subcell, Call Drops due to Abis Terrestrial Link Failure, Call Drops Due to Abis Terrestrial Link Failure on the TRX in the Underlaid Subcell, Call Drops Due to Abis Terrestrial Link Failure on the TRX in the Overlaid Subcell, Call Drops Due to Equipment Failure, Call Drops Due to TRX Failure in the Underlaid Subcell, Call Drops Due to TRX Failure in the Overlaid Subcell, Call Drops due to Resource Check, Call Drops Due to Resource Check on the TRX in the Underlaid Subcell, Call Drops Due to Resource Check on the TRX in the Overlaid Subcell |
A5: Clear Requests Sent on the A Interface |
A6: Call Drops Due to Forced Handover, Call Drops Due to Forced Handover on the TRX in the Underlaid Subcell, Call Drops Due to Forced Handover on the TRX in the Overlaid Subcell |
A10: Successful SDCCH Seizures (Call Type) |
A1: Call Drops Due to ERR IND Received in Stable State, Call Drops Due to the ERR IND Received on the TRX in the Underlaid Subcell in Stable State, Call Drops Due to the ERR IND Received on the TRX in the Overlaid Subcell in Stable State |
A2: Call Drops Due to the CONN FAIL IND Received in Stable State, Call Drops Due to the CONN FAIL IND Received on the TRX in the Underlaid Subcell in Stable State, Call Drops Due to the CONN FAIL IND Received on the TRX in the Overlaid Subcell in Stable State |
A3: Call Drops Due to REL IND Received in Stable State, Call Drops Due to the REL IND Received on the TRX in the Underlaid Subcell in Stable State, Call Drops Due to the REL IND Received on the TRX in the Overlaid Subcell in Stable State |
A4: Call Drops Due to No MRs from MS for a Long Time, Call Drops Due to No MR from the MS on the TRX in the Underlaid Subcell, Call Drops Due to No MR from the MS on the TRX in the Overlaid Subcell, Call Drops due to Abis Terrestrial Link Failure, Call Drops Due to Abis Terrestrial Link Failure on the TRX in the Underlaid Subcell, Call Drops Due to Abis Terrestrial Link Failure on the TRX in the Overlaid Subcell, Call Drops Due to Abis Link Failures in Stable Loopback State, Call Drops Due to Equipment Failure, Call Drops Due to TRX Failure in the Underlaid Subcell, Call Drops Due to TRX Failure in the Overlaid Subcell, Call Drops Due to Resource Check, Call Drops Due to Resource Check on the TRX in the Underlaid Subcell, Call Drops Due to Resource Check on the TRX in the Overlaid Subcell, Call Drops Due to Handover Failure During the Loopback, Call Drops Due to Other Causes in Stable State |
A5: Clear Requests Sent on the A Interface, Call Drops after Answer, Call Drops After Answer on the TRX in the Underlaid Subcell, Call Drops After Answer on the TRX in the Overlaid Subcell |
A6: Call Drops Due to Forced Handover, Call Drops Due to Forced Handover on the TRX in the Underlaid Subcell, Call Drops Due to Forced Handover on the TRX in the Overlaid Subcell, Failed Internal Intra-Cell Handovers (Timer Expired) |
A7: Call Drops Due to Loopback Start Failure |
A8: Successful TCH Seizures on the TRX in the Underlaid Subcell, Successful TCH Seizures on the TRX in the Overlaid Subcell, Call Drops Due to Failures to Return to Normal Call from Loopback |
A9: Successful Connections |
A1: Call Drops Due to ERR IND Received in Stable State, Call Drops Due to the ERR IND Received on the TRX in the Underlaid Subcell in Stable State, Call Drops Due to the ERR IND Received on the TRX in the Overlaid Subcell in Stable State |
A2: Call Drops Due to the CONN FAIL IND Received in Stable State, Call Drops Due to the CONN FAIL IND Received on the TRX in the Underlaid Subcell in Stable State, Call Drops Due to the CONN FAIL IND Received on the TRX in the Overlaid Subcell in Stable State |
A3: Call Drops Due to REL IND Received in Stable State, Call Drops Due to the REL IND Received on the TRX in the Underlaid Subcell in Stable State, Call Drops Due to the REL IND Received on the TRX in the Overlaid Subcell in Stable State |
A4: Call Drops Due to No MRs from MS for a Long Time, Call Drops Due to No MR from the MS on the TRX in the Underlaid Subcell, Call Drops Due to No MR from the MS on the TRX in the Overlaid Subcell, Call Drops due to Abis Terrestrial Link Failure, Call Drops Due to Abis Terrestrial Link Failure on the TRX in the Underlaid Subcell, Call Drops Due to Abis Terrestrial Link Failure on the TRX in the Overlaid Subcell, Call Drops Due to Abis Link Failures in Stable Loopback State, Call Drops Due to Equipment Failure, Call Drops Due to TRX Failure in the Underlaid Subcell, Call Drops Due to TRX Failure in the Overlaid Subcell, Call Drops Due to Resource Check, Call Drops Due to Resource Check on the TRX in the Underlaid Subcell, Call Drops Due to Resource Check on the TRX in the Overlaid Subcell, Call Drops Due to Other Causes in Stable State |
A5: Clear Requests Sent on the A Interface, Call Drops after Answer, Call Drops After Answer on the TRX in the Underlaid Subcell, Call Drops After Answer on the TRX in the Overlaid Subcell |
A6: Call Drops Due to Forced Handover, Call Drops Due to Forced Handover on the TRX in the Underlaid Subcell, Call Drops Due to Forced Handover on the TRX in the Overlaid Subcell, Failed Internal Intra-Cell Handovers (Timer Expired), Failed Outgoing Internal Inter-Cell Handovers (Timer Expired), Call Drops Due to Handover Failure During the Loopback |
A7: Call Drops due to Failures to Return to Normal Call from Loopback |
A8: Successful TCH Seizures on the TRX in the Underlaid Subcell, Successful TCH Seizures on the TRX in the OverLaid Subcell |
A9: Successful Connections |
A10: Successful SDCCH Seizures (Call Type) |
A1: Call Drops Due to ERR IND Received in Stable State, Call Drops Due to the ERR IND Received on the TRX in the Underlaid Subcell in Stable State, Call Drops Due to the ERR IND Received on the TRX in the Overlaid Subcell in Stable State |
A2: Call Drops Due to the CONN FAIL IND Received in Stable State, Call Drops Due to the CONN FAIL IND Received on the TRX in the Underlaid Subcell in Stable State, Call Drops Due to the CONN FAIL IND Received on the TRX in the Overlaid Subcell in Stable State |
A3: Call Drops Due to REL IND Received in Stable State, Call Drops Due to the REL IND Received on the TRX in the Underlaid Subcell in Stable State, Call Drops Due to the REL IND Received on the TRX in the Overlaid Subcell in Stable State |
A4: Call Drops Due to No MRs from MS for a Long Time, Call Drops Due to No MR from the MS on the TRX in the Underlaid Subcell, Call Drops Due to No MR from the MS on the TRX in the Overlaid Subcell, Call Drops due to Abis Terrestrial Link Failure, Call Drops Due to Abis Terrestrial Link Failure on the TRX in the Underlaid Subcell, Call Drops Due to Abis Terrestrial Link Failure on the TRX in the Overlaid Subcell, Call Drops Due to Abis Link Failures in Stable Loopback State, Call Drops Due to Equipment Failure, Call Drops Due to TRX Failure in the Underlaid Subcell, Call Drops Due to TRX Failure in the Overlaid Subcell, Call Drops Due to Resource Check, Call Drops Due to Resource Check on the TRX in the Underlaid Subcell, Call Drops Due to Resource Check on the TRX in the Overlaid Subcell, Call Drops Due to Other Causes in Stable State |
A5: Clear Requests Sent on the A Interface |
A6: Call Drops Due to Forced Handover, Call Drops Due to Forced Handover on the TRX in the Underlaid Subcell, Call Drops Due to Forced Handover on the TRX in the Overlaid Subcell, Failed Outgoing External Inter-Cell Handovers (T8 Expired), Call Drops Due to Handover Failure During the Loopback |
A9: Successful Connections |
A1: Call Drops Due to ERR IND Received in Stable State, Call Drops Due to the ERR IND Received on the TRX in the Underlaid Subcell in Stable State, Call Drops Due to the ERR IND Received on the TRX in the Overlaid Subcell in Stable State |
A2: Call Drops Due to the CONN FAIL IND Received in Stable State, Call Drops Due to the CONN FAIL IND Received on the TRX in the Underlaid Subcell in Stable State, Call Drops Due to the CONN FAIL IND Received on the TRX in the Overlaid Subcell in Stable State |
A3: Call Drops Due to REL IND Received in Stable State, Call Drops Due to the REL IND Received on the TRX in the Underlaid Subcell in Stable State, Call Drops Due to the REL IND Received on the TRX in the Overlaid Subcell in Stable State |
A4: Call Drops Due to No MRs from MS for a Long Time, Call Drops Due to No MR from the MS on the TRX in the Underlaid Subcell, Call Drops Due to No MR from the MS on the TRX in the Overlaid Subcell, Call Drops due to Abis Terrestrial Link Failure, Call Drops Due to Abis Terrestrial Link Failure on the TRX in the Underlaid Subcell, Call Drops Due to Abis Terrestrial Link Failure on the TRX in the Overlaid Subcell, Call Drops Due to Abis Link Failures in Stable Loopback State, Call Drops Due to Equipment Failure, Call Drops Due to TRX Failure in the Underlaid Subcell, Call Drops Due to TRX Failure in the Overlaid Subcell, Call Drops Due to Resource Check, Call Drops Due to Resource Check on the TRX in the Underlaid Subcell, Call Drops Due to Resource Check on the TRX in the Overlaid Subcell, Call Drops Due to Other Causes in Stable State |
A5: Clear Requests Sent on the A Interface |
A6: Call Drops Due to Forced Handover, Call Drops Due to Forced Handover on the TRX in the Underlaid Subcell, Call Drops Due to Forced Handover on the TRX in the Overlaid Subcell, Failed Incoming External Inter-Cell Handovers (Timer Expired), Call Drops Due to Handover Failure During the Loopback |
A7: Call Drops due to Failures to Return to Normal Call from Loopback |
A8: Successful TCH Seizures on the TRX in the Underlaid Subcell, Successful TCH Seizures on the TRX in the OverLaid Subcell |
A9: Successful Connections |
A10: Successful SDCCH Seizures (Call Type) |
Formula
Call Drops on SDCCH (Call Type) =
[Call Drops on Radio Interface (SDCCH )(Call Type)] +
[Call Drops due to Other Causes Received on SDCCH in Stable State (Call Initiation)(SDCCH)] +
[Call Drops due to Other Causes Received on SDCCH in Stable State (Paging Response)(SDCCH)] +
[Call Drops due to Other Causes Received on SDCCH in Stable State (Call Re-establishment)(SDCCH)] +
[Call Drops due to Other Causes Received on SDCCH in Stable State (Emergency Call)(SDCCH)]