Measurement Counter
CM337:CELL_CALL_DROPS_AFTER_CONN
Description
In the assignment procedure, a call is set up when the BSC receives the CONNECT and the CONNECT ACKNOWLEDGE messages from the CC layer. In the incoming-BSC handover procedure, a call is set up when the target cell sends a Handover Complete message to the MSC. In the internal BSC handover process, a call is set up when a HANDOVER PERFORMED message is sent to the MSC after the MS is handed over to the target cell. The BSC measures this counter after the assignment procedure or the handover procedure.
Unit
Integer number or integer.
Measurement Point
1. When the MS is in normal conversation on the radio channel, the BSC detects a CONNECT or CONNECT ACKNOWLEDGE message. If an abnormal case for a radio link layer connection occurs, the BTS sends an ERROR INDICATION message to the BSC. This counter is measured when the BSC receives the ERROR INDICATION message. For details, refer to GSM Rec. 08.58.
2. When the MS is in normal conversation on the radio channel, the BSC detects a CONNECT or CONNECT ACKNOWLEDGE message. If a broken radio link connection or hardware fault occurs, the BTS sends a CONNECTION FAILURE INDICATION message to the BSC. This counter is measured when the BSC receives the CONNECTION FAILURE INDICATION message. For details, refer to GSM Rec. 08.58.
3. This counter is measured if the timer expires before the BSC receives the CLEAR HANDOVER message from the MSC during the outgoing BSC handover procedure.
4. In the intra-BSC handover procedure, if the timer expires before the target cell receives the HANDOVER COMPLETE message, the target cell sends an Inter Clear message to the originating cell to inform it of the handover failure. This counter is measured in the originating cell when the Inter Clear message is received.
5. In the intra-BSC handover procedure, if the timer expires before the target cell receives the HANDOVER COMPLETE message, the target cell sends an Inter Clear message to the originating cell to inform it of the handover failure. This counter is measured in the originating cell when the Inter Clear message is received.
6. During the intra-BSC handover procedure, if the MS returns the original channel because of a handover failure, the originating cell releases the terrestrial connection and restores the network. This counter is measured if a call drop occurs due to a timeout or failure occurs in the network restoration.
7. If the BSC and the MSC supports preemption, the radio resource used by an MS with lower priority may be preempted by an MS with higher priority, leading to the call drop of the MS with lower priority.
8. This counter is measured when a broken RSL is detected on the traffic channel on the TRX used.
This counter is calculated at A1, A2, A3, and A4, as shown in Figure 1, Figure 2, Figure 3, and Figure 4.
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 after Answer =
[Call Drops after Answer (TCHF) (Traffic Channel)] +
[Call Drops after Answer (TCHH) (Traffic Channel)]