Paging Sucess rate (Huawei network)

[gogotchiya83]

In our network we have some problems in paging (90 % for the whole network) by using this formulas :

Paging success rate = Paging response times/Paging request times x 100%

The first paging request presents 83%.
After the second paging request presents 12%.
After the third paging request presents 5%.

What do you think about this distribution of request?

From BSS part : the paging sucess rate = 77% (Circuit paging (A-interface) success rate (%) = Successful circuit pagings of Abis interface / Received circuit paging messages from MSC Successful circuit pagings of Abis interface)

so if we re-calculate this rate without including the second and the third paging request (17%), we can find the value gived by the NSS part : 0,77/(1-0,16) = 90%

The existing value of the paging times is 3, whose paging duration is 5 seconds, 5 seconds and 4 seconds.
The all paging area is current LAC.

IMSI detach timer (msc) is 120 mins.
Subscriber periodic timer of BSS (bss) is 54 mins.

What do you think about these values of parameters?
Hiw can i find the degraded cells impacting the BSCs? (if you have some formulas with counters in order to calculate this rate by cell)

Thanks


Implicit IMSI detach timer must cooperate with Subscriber periodic timer of BSS (must be greater than T3212).

[jayk]

Check below mentioned counters to find paging deletions/expires on cell level. If there are deletions on cell level then change cell level paging related parameters like MFR, BCCH Configuration(Combined or non-combined), slots assigned for AG and PCH channels.

CELL.CIRCUIT.PCH.DEL-Number of Deletions of the Paging for CS Services on the PCH
CELL.CIRCUIT.PCH.EXP-Number of Expiries of the Paging for CS Services on the PCH

Regards, jack.

[gogotchiya83]

Thanks for you answer,
How to find the cell impacting the BSC?
PLZ can you share a document describing the tuning of such parameteres? (MFR...) and the effect on PSR?

[Fado]

you should also check the settings in msc as the total number of paging will be paging times of bssxMSC..also check if PCHs are congested or not...you may need to have smaller LAC if you have congestion or change the number of reserved channels as per your requirements..cheers!

[gogotchiya83]

Thanks for your answer,
I checked the counters : CELL.CIRCUIT.PCH.DEL-Number of Deletions of the Paging for CS Services on the PCH & CELL.CIRCUIT.PCH.EXP-Number of Expiries of the Paging for CS Services on the PCH , and i found a very high value for some LAC, what should i understand from that? is'it a PCH congestion?
how to check the PCH congestion? and what is the reasons for that?
I notice that T3212 = 54 min (9x6) , do you think that this setting can impact the pch congestion?
...

[jayk]

T3212 value does not effect Paging. Paging Deletion and Paging expiry is high means optimization is required. Check out the maximum capability of BSC for paging in a hour, if current paging requests are higher than the Max Paging load then plan more LAC. Regards, jack.

[gogotchiya83]

but if we have small T3212 => many locations update => high signaling => PCH congestion ?

what about the MSC timers ?

i found that For an LA with a large capacity, a paging message should not be resent for too many times and the resending interval should not be too short. Otherwise, this may cause BTS overload, BSC CPU overload, and then discarding of many paging messages. As a result, the paging success rate falls sharply.

Thanks in advance

[Fado]

hi gogotchiya83, too many LU will cause sd congestion not PCH..pch is on ccch..cheers!

[jayk]

Resending interval should not be short and what is threshold to consider the value as short? My suggestion is to follow the default parameters in this scenarios. A paging message is sent for the configured no. of times only and buffer should contain the accumulation of paging messages. The bottleneck can be at cell or the Paging(Mobile Terminated Calls and Terminating SMS) can be very high to cause paging deletion or expiry. As Fado has mentioned, Location Updates uses another channel so T3212 does not effect Paging in Network.


but if we have small T3212 => many locations update => high signaling => PCH congestion ?

what about the MSC timers ?

i found that For an LA with a large capacity, a paging message should not be resent for too many times and the resending interval should not be too short. Otherwise, this may cause BTS overload, BSC CPU overload, and then discarding of many paging messages. As a result, the paging success rate falls sharply.

Thanks in advance

[gogotchiya83]

Thanks for your answer;
I'm still looking for how to find the cell impacting the PSR for one LAC?
I user the counter CELL.CIRCUIT.PCH.DEL-Number of Deletions of the Paging for CS Services on the PCH & CELL.CIRCUIT.PCH.EXP-Number of Expiries of the Paging for CS Services on the PCH ; and they gived me an explanation on the degradation of one LAC; but the other LAC which suffering from this problem they don't have the PCH Load? so what can be the problem?
if it is a problem of coverage of some cells, what is the weight of these cells? if i remove these cells from my LAC what will be the result? (Weight)

[jayk]

High traffic carrying cells contribute more weight to PSR Degradation. The customer complaints can help to locate cells with Paging loss. It is not just the coverage but interference on BCCH that can effect Paging Success Rate.