Call Drops on TCHF Due to BSC Loopback Start Failure (Others)

Measurement Counter

M3121:CELL_CALL_DROPS_BSCLOOP_FAIL_OTHER_TCHF

Description

After the call is put through or the incoming BSC handover for the speech service is complete, the BSC selects the BSS local switch policy, determines the local switch start conditions, and performs local switch call detection in the local loopback procedure. If all the local switch conditions are met, the BSC local loopback procedure is started. Within the BSC, the call processing module initiating loopback start at one end sends a loopback request message to the call processing module at the peer end. If the loopback fails because of other reasons (rather than territorial resource request failure), the BSC physical layer responds to the call processing module initiating the loopback with a loopback acknowledgement message. The BSC regards it as a call drop and releases the call directly.

This measurement provides the number of call drops on TCHF due to BSC loopback start failure (others).

Unit

Integer number or integer.

Measurement Point

After the BSC receives the CONNECT ACK message from the MSC in the MS terminated call procedure, as shown in Figure 1(A1), or after the BSC receives the HANDOVER CMP message from the MS in the incoming BSC handover procedure for the speech service, as shown in Figure 2 (B1), the BSC selects the BSS local switch policy, determines the local switch start conditions, and performs local switch call detection in the local loopback procedure. If all the local switch conditions are met, the BSC local loopback procedure is started. Within the BSC, the call processing module initiating loopback start at one end sends a loopback request message to the call processing module at the peer end. If the loopback fails because of other reasons (rather than territorial resource request failure), the BSC physical layer responds to the call processing module initiating the loopback with a loopback acknowledgement message. The BSC regards it as a call drop and releases the call directly. If the channel that carries the call during the call drop is a TCHF, this counter is measured.

Figure 1 Local switch in MS terminated call procedure

Figure 2 Local switch in the incoming-BSC handover procedure for the speech service

Formula

This is an original counter without involving any formula.