Measurement Counter
A9118:DOWN_GPRS_TRANS_INTERRUPT_TIMES
Description
This measurement provides the number of intermitted downlink GPRS TBF transfers in a granularity period. A high measurement value is yielded because the downlink PDU buffer is emptied upon abnormal downlink GPRS TBF releases due to SUSPEND, FLUSH, or failed downlink re-establishments due to other causes.
Unit
Integer number or integer.
Measurement Point
The downlink PDU buffer is emptied upon downlink GPRS TBF abnormal release due to SUSPEND. When a class B MS initiates a CS service request, the BSC suspends all the PS services of the MS irrespective of the MS status. When the MS is in transmission state and the downlink GPRS TBF exists, the MS initiates the suspending procedure by sending a SUSPEND message and suspends the PS services. Accordingly, the BSC releases the downlink GPRS TBF. If the suspension lasts for a long time, the PDU buffer is emptied. Figure 1 shows the procedure of intermitted downlink GPRS TBF transfer when the MS sends a SUSPEND message to the BSC. When the BSC receives the SUSPEND message, and the suspension lasts for a long time (see measurement point A), the counter is incremented by one.
Figure 1 Intermitted downlink GRPS transfer due to SUSPEND
The downlink PDU buffer is emptied upon downlink GPRS TBF abnormal release due to FLUSH. When the MS reselects a new cell, the SGSN initiates the cell updating procedure and sends a FLUSH LL PDU to the BSC. Accordingly, the BSC suspends all the PS services of the MS in the original cell irrespective of the MS status. When the MS is in transmission state and the downlink GPRS TBF exists, the BSC releases the downlink GPRS TBF and deletes the downlink PDU buffers which are soon expired when receiving the FLUSH LL PDU from the SGSN. Figure 2 shows the procedure of intermitted downlink GPRS TBF transfer when the BSC receives the FLUSH LL PDU. When the BSC receives the FLUSH LL PDU message (see measurement point A), the counter is incremented by one.
- Figure 2 Intermitted downlink GRPS transfer due to FLUSH
The downlink PDU buffer is emptied upon downlink GPRS TBF abnormal release due to other causes. The downlink PDU buffer is emptied when the re-establishment of downlink GPRS TBF fails after it is released abnormally due to other causes (such as N3105 overflow, no channel, preempted channel). Figure 3 shows the procedure of intermitted downlink GPRS TBF transfer due to other causes. When the downlink GPRS TBF is released (see measurement point A), the counter is incremented by one.
Figure 3 Intermitted downlink GPRS transfer due to other causes
Formula
This is an original counter without involving any formula.