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

Measurement Counter

A9304: DOWN_EGPRS_TBF_ESTB_FAIL_MS_NO_RESP

Description

This measurement provides the number of failed downlink EGPRS 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. This measurement indicates the downlink assignment success rate.

Unit

Integer number or integer.

Measurement Point

The downlink EGPRS TBF establishment failures due to no response from the MS involve the following aspects:

Failed downlink EGPRS TBF establishment initiated on the CCCH due to MS no response

During the downlink EGPRS TBF establishment procedure, the BSC sends the POLLING message to the MS to obtain the TA value. The BSC also 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 in the reserved blocks, then the BSC sends downlink immediate assignment messages repeatedly until the maximum retry times are exceeded. Figure 1 shows the procedure of downlink EGPRS TBF establishment failure due to no response from the MS. Each time the number of BSC retry times exceeds the maximum retry time (see measurement point A), the counter is incremented by one.

Figure 1 Failed downlink EGPRS TBF establishment initiated on the CCCH due to no response from the MS
Failed downlink EGPRS TBF establishment initiated on the PACCH due to MS no response

The BSC establishes the downlink EGPRS TBF in two ways. The BSC initiates a new downlink EGPRS TBF establishment request during the transmission of the current uplink EGPRS TBF or the release of the current downlink EGPRS TBF. Alternatively, the BSC reassigns downlink resources for the EGPRS TBF during the transmission of the current downlink EGPRS 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 EGPRS TBF establishment initiated on the PACCH due to no response from the MS

Formula

This is an original counter without involving any formula.