Measurement Counter
M3220:CELL_CALL_DROPS_BSCLOOP_FAIL_APPLY_TRSL_FAIL_TCHH
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. At the call processing module at the loopback start end, the BSC reconnects the transmission channel between the Ater interface and the Abis interface, and requests TC resources. If the reconnection or request fails, the BSC physical layer responds to the call processing module with a loopback acknowledgement message with the cause value of Territorial Resource Request Failure. The BSC regards it as a call drop and releases the call directly. The BSC loopback start fails.
This measurement provides the number of call drops on TCHH due to BSC loopback start failure (territorial resource request failure).
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. At the call processing module at the loopback start end, the BSC reconnects the transmission channel between the Ater interface and the Abis interface, and requests TC resources. If the reconnection or request fails, the BSC physical layer responds to the call processing module with a loopback acknowledgement message with the cause value of Territorial Resource Request Failure. 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 TCHH, this counter is measured.
Formula
This is an original counter without involving any formula.