Call Drops on Radio Interface in Stable State (TCH Qua Signaling Channel)

Measurement Counter

CM3606:CELL_SIG_CHAN_STATIC_STATE_CALL_TCH_DROP_TIMES

Description

This measurement provides the number of calls released because of the ERR IND, CONN FAIL IND, and REL IND messages received by the BSC.

The MS seizes a signaling channel in any of the following conditions:

1. In the immediate assignment procedure, the BTS sends an EST IND message to the BSC.
2. The MS sends an HO CMP message to the BSC, and the MS seizures a signaling channel.

Unit

Integer number or integer.

Measurement Point

If the signaling is processed for the call and if a TCH is seized, this counter is measured in any of 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 BSC. For details, refer to GSM Rec. 08.58.

This counter is calculated at A1, A2, and A3, as shown in Figure 1.

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)

Formula

Call Drops on Radio Interface in Stable State (TCH Qua Signaling Channel) =

[Call Drops on Signaling Channel in Stable State (Error Indication) (TCH)] +

[Call Drops on Signaling Channel in Stable State (Connection Failure) (TCH)] +

[Call Drops on Signaling Channel in Stable State (Release Indication) (TCH)]