Failed TCH Seizures in TCH Handovers due to Busy TCH (Traffic Channel)

Measurement Counter

K3011B:CELL_KPI_TCH_HO_CONGEST_TRAF

Description

This measurement provides the number of failed TCH (traffic channel) seizures due to no TCH available in TCH handovers.

Unit

Integer number or integer.

Measurement Point

Incoming internal inter-cell handover According to the measurement report received from the MS, the BSC decides to initiate the incoming internal inter-cell handover. If the channel request fails because of no channel available, the BSC measures the counter. The measurement object is the target cell. See measurement point C in Figure 1and Figure 2

Figure 1 Internal inter-cell handover procedure (excluding directed retry)

Figure 2 Internal inter-cell handover procedure (directed retry)

Incoming external inter-cell handover BSC2 receives the HO REQ message from the MSC and decodes it. If the decoding is successful, BSC2 requests a channel from the target cell. The measurement is triggered when the request fails because of no channel available. The measurement is based on the channel type. See measurement point C in Figure 3and Figure 4.

Figure 3 External handover procedure (excluding directed retry)

Figure 4 External handover procedure (directed retry)

Formula

Failed TCH Seizures in TCH Handovers due to Busy TCH (Traffic Channel) =

[Failed Internal Intra-Cell Handovers (Channel Unavailable) (TCH)] +

[Failed Incoming Internal Inter-Cell Handovers (Channel Unavailable) (TCH)] +

[Failed Incoming External Inter-Cell Handovers (Channel Unavailable) (TCH)]