S4015A: TRX_TX_SIGNALING_LOST
This measurement provides the number of signaling-plane packets that the TRX sends to the BSC over the HDLC path but get lost due to transmission congestion or abnormal communications.
Integer number or integer.
Once the TRX detects that the link congestion exceeds a predefined time threshold, it discards the signaling-plane packets in the sending queue and performs the measurement. The BTS periodically reports the result, and the BTSM disassembles the packets and processes the measurement results.
This is an original counter without involving any formula.