Number of Failed Downlink GPRS TBF Establishments due to MS No Response

Measurement Counter

A9104:DOWN_GPRS_TBF_ESTB_FAIL_MS_NO_RESP

Description

This measurement provides the number of failed downlink GPRS TBF establishments due to no response from the MS in a granularity period. A high measurement value is yielded because the radio quality of the cell is bad. The downlink GPRS TBF establishments failures indicate the downlink assignment success rate.

Unit

Integer number or integer.

Measurement Point

The failed downlink GPRS TBF establishment due to no response from the MS involve the following aspects:

Failed downlink GPRS TBF establishment on the CCCH due to no response from the MS

In the downlink GPRS TBF establishment procedure, the BSC sends the POLLING message to the MS to obtain the TA value. The BSC also reserves the block resource for the MS to respond with the assignment acknowledgement message. If the BSC does not receive the PACKET CONTROL ACKNOWLEDGEMENT message from the MS on the reserved block resources, then the BSC sends downlink immediate assignment messages repeatedly until the maximum retry times are exceeded. Figure 1 shows the procedure of failed downlink GPRS TBF establishment due to no response from the MS. Each time the maximum retry times of the BSC are exceeded (see measurement point A), the counter is incremented by one.

Figure 1 Failed downlink GPRS TBF establishment on the CCCH due to no response from the MS
Failed downlink GPRS TBF establishment on the PACCH due to no response from the MS
The BSC establishes the downlink GPRS TBF in two ways:
- Initiate a new downlink GPRS TBF establishment request during the transmission process of the current uplink GPRS TBF.
- Initiate a new downlink GPRS TBF establishment request during the release process of the current downlink TBF.
Reassigns downlink resources for the GPRS TBF during the transmission process of the current downlink GPRS TBF. The BSC sends the PACKET DOWNLINK ASSIGNMENT message and reserves the blocks for the MS to respond with the assignment acknowledgement message. If the BSC does not receive the PACKET CONTROL ACKNOWLEDGEMENT message from the MS on the reserved block resources, then the BSC sends downlink packet assignment messages repeatedly until the maximum retry times are exceeded. Figure 2 shows the procedure of failed downlink GPRS TBF establishment due to no response from the MS. Each time the resend times exceed the maximum retry times (see measurement point A), the counter is incremented by one.
Figure 2 Failed downlink GPRS TBF establishment on the PACCH due to no response from the MS

Formula

This is an original counter without involving any formula.