Measurement of Call Drops Due to Forced Handover

Measurement Counter

M305:CELL_CALL_DROPS_FORCE_HO_SD

M345:CELL_CALL_DROPS_FORCE_HO_TCHF_SIG

M315:CELL_CALL_DROPS_FORCE_HO_TCHF_TRAF

M355:CELL_CALL_DROPS_FORCE_HO_TCHH_SIG

M325:CELL_CALL_DROPS_FORCE_HO_TCHH_TRAF

M3614A:CELL_CALL_DROPS_FORCE_HO_SIG_ULCELL

M3314B:CELL_CALL_DROPS_FORCE_HO_TRAF_ULCELL

M3624A:CELL_CALL_DROPS_FORCE_HO_SIG_OLCELL

M3324B:CELL_CALL_DROPS_FORCE_HO_TRAF_OLCELL

Description

After an MS seizes a channel, if the system initiates a forced handover and the handover fails, the BSC may initiate a call release procedure. This measurement provides the number of call drops due to forced handovers on the basis of the channel type (SDCCH, TCHF, or TCHH), the service type (signaling or traffic), and the concentric attribute (overlaid subcell or underlaid subcell).

Unit

Integer number or integer.

Measurement Point

This counter is measured in the following situations:

The timer expires before the outgoing BSC handover command is received, or the CLEAR REQUEST message is received from the MSC before the timer expires, and the handover cause is OM intervention, MSC triggering, or preemption.
A call drop occurs during the emergency handover due to PDCH assignment, or ‏the handover due to TRX mutual aid, preemption, or blocking of cells, TRXs, and channels.

The specific counter is measured at A6, as shown in Figure 1, Figure 2, Figure 3, Figure 4, and Figure 5.

Figure 1 Call drops in the immediate assignment (including very early assignment) procedure

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)

Figure 2 Call drops in the assignment and intra-cell handover (TCH handover) procedure

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

Figure 3 Call drops in the intra-BSC handover procedure (including the signaling channel and TCH)

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)

Figure 4 Call drops in the outgoing BSC handover procedure (including the signaling channel and TCH)

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

Figure 5 Call drops in the incoming BSC handover procedure (including the signaling channel and TCH)

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

This is an original counter without involving any formula.