c- Paging problem

[sad_RNP]

Dear Expert i have problem in one cell , is Number you have called is out of coverage after check KPI for the problematic cell , i found the A351:Number of Discarded Re-paging Messages for CS Services is high as show below so , pls your support to solve it , i have check the following 1- transmission is ok 2- SDCCH congestion , nothing , is ok 3- this is high traffic cell (content 4 Trx GSM900 +2 TRX DCS1800)

[sabila]

try add BCH for this cell
and monitor

[trongcongbk]

Please check parameter: BS_PA_MFRMS

"Frame Number Coding Between Identical Paging

Frame number coding between identical paging is BS_PA_MFRMS (MFR for short).
I. Definition

According to GSM regulations, each MS (corresponding to an IMSI) belongs to a paging group (for calculation of paging groups, see GSM regulation 05.02). Each paging group in a cell corresponds to a paging subchannel. According to its IMSI, the MS calculates the paging group that it belongs to, and then calculates the location of paging subchannel that belongs to the paging group. The MS only receives the signals of the paging subchannel that it belongs to, and neglects that of other paging subchannels. In addition, the MS even powers off some hardware of itself during other paging subchannel to lower power cost of itself.
The number of paging channel multiframe (MFR) is the number of multiframes used in a period of paging subchannel. The MFR determines the number of paging subchannels that the cell PCH is divided into.
II. Format

The MFR ranges from 2 to 9, which respectively means that the same paging group cycles in a period of 2 to 9 multiframes.
III. Configuration and Influence

According to the definition of CCCH, AG, and MFT, you can calculate the number of paging channel in each cell.

• When the CCCH and SDCCH share a physical channel, there is (3 - AG) MFRs.
• When the CCCH and SDCCH share a physical channel, there is (9 - AG) MFRs.

According to the previous analysis, the greater the MFR is, the more the paging channels of the cell are (see the calculation of paging groups in GSM regulation 05.02). Theoretically, the capacity of paging channels does not increase with the increase of MFR. The number of buffers for buffering paging messages on each base transceiver station (BTS) increases. The paging messages are sent more evenly both in time and space, so it seldom occurs that the paging messages overflow in the buffers so call lost occurs (related to functions by equipment providers).
However, to enjoy the previous advantages, you will have a longer delay of paging messages on the radio channels. The greater the MFR is, the greater the delay of paging messages in the space is, and the lower the average service performance of the system is. Therefore, the MFR is an important parameter in network optimization.
The following principle caters for configuring MFR:
The configured strategy for buffers of each equipment provider is different, so you must select the MFR properly so that the paging messages do not overflow on PCH. Based on this, configure the parameter as small as possible. In addition, you must measurement the overflow situations of PCH periodically while the network is running, and adjust MFR accordingly.
IV. Precautions

Any paging message of the same location area must be sent to all cells in the location areas at the same time, so the PCH capacity of each cell in the location area must be equivalent or close to each other. Otherwise, you must consider smaller PCH capacity as the evidence for designing location area."