Number of Discarded PDUs in Buffer After FLUSH LL PDUs Received by BSSGP Sublayer

Measurement Counter

L9905:CELL_BSSGP_TRAN_RX_FLUSH_LL_PDU_DISCARD

Description

This measurement provides the number of times that the PDUs in the buffer are discarded after the BSC receives the FLUSH LL PDUs in a granularity period. This measurement is used to distinguish the intra-BSC or inter-BSC cell reselection from the route update. In the process of cell reselection, if the FLUSH LL PDUs sent from the SGSN to the BSC do not contain the information about the target cell, all the LLC PDUs in the buffer of the originating cell will be deleted. In this situation, PS services may be disrupted until the LLC or IP layer transfers the data again.

Unit

Integer number or integer.

Measurement Point

The following figure shows the process where the SGSN sends a FLUSH LL PDU to the BSC. In a granularity period, every time PDUs in the buffer are discarded after the BSC receives a FLUSH LL PDU message (see measurement point A in Figure 1), the counter is incremented by one.

Figure 1 FLUSH LL PDU received by the BSSGP sublayer

Formula

This is an original counter without involving any formula.