2G Paging problem need help

[kadir]

Hi all;

i have a problem about, 2g. one of our customers can make a call but, sometimes the people can not reach him even his phone power on and the signal level and quality is good. what is the possible reason of this situation?

when i check the trace, the paging is sending but the ms doesnt reply it.

please help

[ash_or]

Try to check paging load in each LAC...
mayble your network is high paging load.

[kamy]

which radio access technology your network is using, CDMA or GSM?

[kadir]

which radio access technology your network is using, CDMA or GSM?


we are using gsm tech. and our equipments are nokia.

[RF engineer]

did you check imsi attach and detach timer on switch part and t3212 on bss side it seems the switch timer is less than bss

[fshoaib]

Please check whether subscriber lies on LAC boundary and is constantly doing cell reselection

[leelio]

check if there is any sd/tch congestion on cells serving the customer,otherwise re-check paging plan on both MSC and BSS

[danikd]

Hi all;

i have a problem about, 2g. one of our customers can make a call but, sometimes the people can not reach him even his phone power on and the signal level and quality is good. what is the possible reason of this situation?

when i check the trace, the paging is sending but the ms doesnt reply it.

please help

Dear,

Paging is a complicate problem, let give you some ideas for what you need to check prior to solving this.

1. At radio interface the most critical part for paging is a paging channel resources i.e. how many paging blocks available. Here the configuration of BCCH timeslot is very important. Since paging channel is a resource of entire Location Area (and not a cell resource), you can not mix Combined and Non-Combined BCCH timeslot configurations within the same paging area.
2. Paging channel load - the paging channel in maximal configuration can have 9 paging blocks and at minimal configuration (Combined BCCH) 3 paging blocks. Also AGCH channel may reduce Paging channel blocks available.
3. Now the paging strategy - you can define paging by TMSI or paging by IMSI - paging by TMSI is most efficient, since 1 paging block may contain 4 pages by TMSI and only 2 pages by IMSI.
4. Maximal configuration of 9 paging blocks may provide a paging capacity of 144 pages per second (9 paging blocks *4 pages by TMSI * 4 CCCH multiframes per second). The minimal configuration may support only 24 pages per second (3 paging blocks * 2 pages by IMSI * 4 CCCH multiframes per second)

As you may see here the variation of paging channel size per sector is not applicable. PAGING CHANNEL configuration should be EQUAL for all cells with in the same location area.

Typically vendor do not suggest to cross a load of 50% of paging channel capacity in order to be able to handle traffic peaks that may suddenly occur.
You can monitor the paging load in Nokia GSM network by looking at PAGING_MSG_SENT counter. Just divide the hourly value by 3600 to get it in average pages per second (be sure that received value thru all hours never crossing 50% load for available configuration of paging channels for all cells in location area).

Now more. For paging important not only air interface configuration, but also A-bis configuration. In order to support high load on paging channel you have to validate that A-bis interface has 64kbps signalling link for BCCH TRX otherwise you may lost pages due to A-bis congestion.

One more tip, you can check additional parameter on MSC side - Implicit Detach this parameter should be greater than T3212 (Periodic_Update_MS)

Need more clarifications, you can ask))))

[Ben0723]

Dear,

Paging is a complicate problem, let give you some ideas for what you need to check prior to solving this.

1. At radio interface the most critical part for paging is a paging channel resources i.e. how many paging blocks available. Here the configuration of BCCH timeslot is very important. Since paging channel is a resource of entire Location Area (and not a cell resource), you can not mix Combined and Non-Combined BCCH timeslot configurations within the same paging area.
2. Paging channel load - the paging channel in maximal configuration can have 9 paging blocks and at minimal configuration (Combined BCCH) 3 paging blocks. Also AGCH channel may reduce Paging channel blocks available.
3. Now the paging strategy - you can define paging by TMSI or paging by IMSI - paging by TMSI is most efficient, since 1 paging block may contain 4 pages by TMSI and only 2 pages by IMSI.
4. Maximal configuration of 9 paging blocks may provide a paging capacity of 144 pages per second (9 paging blocks *4 pages by TMSI * 4 CCCH multiframes per second). The minimal configuration may support only 24 pages per second (3 paging blocks * 2 pages by IMSI * 4 CCCH multiframes per second)

As you may see here the variation of paging channel size per sector is not applicable. PAGING CHANNEL configuration should be EQUAL for all cells with in the same location area.

Typically vendor do not suggest to cross a load of 50% of paging channel capacity in order to be able to handle traffic peaks that may suddenly occur.
You can monitor the paging load in Nokia GSM network by looking at PAGING_MSG_SENT counter. Just divide the hourly value by 3600 to get it in average pages per second (be sure that received value thru all hours never crossing 50% load for available configuration of paging channels for all cells in location area).

Now more. For paging important not only air interface configuration, but also A-bis configuration. In order to support high load on paging channel you have to validate that A-bis interface has 64kbps signalling link for BCCH TRX otherwise you may lost pages due to A-bis congestion.

One more tip, you can check additional parameter on MSC side - Implicit Detach this parameter should be greater than T3212 (Periodic_Update_MS)

Need more clarifications, you can ask))))


I have a problem.a lac with 140000 pages per hour and 294 cells. at 11:00 AM everyday there is 40 cells over paging load .This lac's config is 7PCH*2pages*4TMSI*.why over load ? why only 40 cells over load ?

[mohyedeen_alkousy]

you have paging overload in a group of cells because these cells have different setting of parameters (multiframes between paging groups and AGCH reserved blocks) than the others

play with these parameters to try to relief paging congestion

[usama0795]

Yeah maybe u have issue with paging due to abnormally high cell reslection but I had a similar issue doing Drive Test some couple of months ago both Mobile Stations are with me and camped on the same cell I am making short calls and continuously over a preiod of time I got Not Responding when dialing MS2......reason is shown below can anyone highlight the what does it mean..........as i wanted to due the same thing again with trace enabled on both source and destination numbers maybe some issue at NSS end but couldnt due to some other projtecs......as every time I got this PROGRESS message on MS1 after Call Setup then the fat lady singed Destination MS is Not Reponding.....Destination MS is Not Reponding.....

[Ben0723]

you have paging overload in a group of cells because these cells have different setting of parameters (multiframes between paging groups and AGCH reserved blocks) than the others

play with these parameters to try to relief paging congestion

i check it . and these cells have the same setting of parameters (multiframes = 2 between paging groups and AGCH reserved blocks = 2) :(

[chiheb]

Hi

I recommend you to check the counters PAGTOOLD and PAGTOCONG on cell level. they should be zero, if not please to check your parameters:
1-combined BCCH or not (prrefred non-combined BCCH).
2-recommended resreved AGCH is 1 (not 2 like your set)
3- check your stratigy of paging ( recomended to be local with TMSI)
4- otherwise you need to review your LA size.

Regards

[Ben0723]

Hi

I recommend you to check the counters PAGTOOLD and PAGTOCONG on cell level. they should be zero, if not please to check your parameters:
1-combined BCCH or not (prrefred non-combined BCCH).
2-recommended resreved AGCH is 1 (not 2 like your set)
3- check your stratigy of paging ( recomended to be local with TMSI)
4- otherwise you need to review your LA size.

Regards

if resreved AGCH set to 1,the AGCH will congest also?:)

[darshanmalde]

also one can reduce t3212

[Alaa]

Hi all;

i have a problem about, 2g. one of our customers can make a call but, sometimes the people can not reach him even his phone power on and the signal level and quality is good. what is the possible reason of this situation?

when i check the trace, the paging is sending but the ms doesnt reply it.

please help

The paging progress and investigation is not something simple where a lot of nodes are involved, it is not clear if the problem you have is general over all the cells belong to same BSC and/or MSC, or in particular cells, and the vendors of the BSS and NSS are not mentioned , as you said you have good quality and SS, and I believe that you already checked that you don’t have SDCCH congestion, u don’t have congestion in the Abis (related to the vendor, signaling protocol is used). Anyhow you could have congestion in the BTS queue where MFRMS=2 this sitting will improve the discarded pages due to too old but could increase the discarded due to congestion so you need to choose the best value according to your situation which make the total discarded is minimum
There is set of parameters and timers need to be check in the MSC side and the most important which could be the one affecting your paging is BTDM in MSC which should be greater than or equal to T3212

Hope this will help you, if not im happy to discuss it more
Regards
Alaa

[Ben0723]

also one can reduce t3212

reduce t3212 will increase paging discard too.

[Ben0723]

The paging progress and investigation is not something simple where a lot of nodes are involved, it is not clear if the problem you have is general over all the cells belong to same BSC and/or MSC, or in particular cells, and the vendors of the BSS and NSS are not mentioned , as you said you have good quality and SS, and I believe that you already checked that you don’t have SDCCH congestion, u don’t have congestion in the Abis (related to the vendor, signaling protocol is used). Anyhow you could have congestion in the BTS queue where MFRMS=2 this sitting will improve the discarded pages due to too old but could increase the discarded due to congestion so you need to choose the best value according to your situation which make the total discarded is minimum
There is set of parameters and timers need to be check in the MSC side and the most important which could be the one affecting your paging is BTDM in MSC which should be greater than or equal to T3212

Hope this will help you, if not im happy to discuss it more
Regards
Alaa

Hi,I don't understand.can u explan what this mean :Anyhow you could have congestion in the BTS queue where MFRMS=2 this sitting will improve the discarded pages due to too old but could increase the discarded due to congestion so you need to choose the best value according to your situation which make the total discarded is minimum. Thanks a lot~!

[Alaa]

Hi,I don't understand.can u explan what this mean :Anyhow you could have congestion in the BTS queue where MFRMS=2 this sitting will improve the discarded pages due to too old but could increase the discarded due to congestion so you need to choose the best value according to your situation which make the total discarded is minimum. Thanks a lot~!

Hi;
Incoming Paging Commands are buffered in a queue (one for each paging group). The queue for each paging group in the BTS can fit between 6 and 14 pages, depending on the number of paging groups, now by reducing MFRMS, the discarded pages due to too old will be reduced dramatically where the number of paging groups will be less and the paging messages transmission per paging group will become faster (shorter period), the discarded pages due to congestion in the queue could be increase sometimes while as you see that reducing the number of paging groups is associated with increase in the length of the BTS paging queue but not more than 14 pages. usually the weight of discarded pages due to too old are much bigger than the discarded due to queue congestion, unless there is huge paging load, so by readings the values of the discarded paging counters you can decide the best value giving you the lowest discarded possible, then and if the paging load is high, you need to have LAC splitting (I believe all the related parameters are tuned will, like for example ATT to be yes).
Hope that I clarified this point

[k4conk]

Hi;
Incoming Paging Commands are buffered in a queue (one for each paging group). The queue for each paging group in the BTS can fit between 6 and 14 pages, depending on the number of paging groups, now by reducing MFRMS, the discarded pages due to too old will be reduced dramatically where the number of paging groups will be less and the paging messages transmission per paging group will become faster (shorter period), the discarded pages due to congestion in the queue could be increase sometimes while as you see that reducing the number of paging groups is associated with increase in the length of the BTS paging queue but not more than 14 pages. usually the weight of discarded pages due to too old are much bigger than the discarded due to queue congestion, unless there is huge paging load, so by readings the values of the discarded paging counters you can decide the best value giving you the lowest discarded possible, then and if the paging load is high, you need to have LAC splitting (I believe all the related parameters are tuned will, like for example ATT to be yes).
Hope that I clarified this point


Hi Brother.. how about with SIEMEN/HUAWEI/E******* related with parameter MFRMS.. may be you can give explanation about that parameter..??

And do you mean also "discard page due too old & discard due to congestion" different parameter/counter..?? so how to know if due to old or due to congetsion..?? sory if my question still basic cos i'm new at optimization.. thanks a lot

[khalids]

Hello guys, This might be insignificant but might have been overlooked. If the cell in question is on a LAC border and you are using paging strategy of LAC--> NBR LAC--->NBR LAC.

Ensure that neighboring LACs are defined as neighbors to each other.

Br

[gageloz]

Hi all;

i have a problem about, 2g. one of our customers can make a call but, sometimes the people can not reach him even his phone power on and the signal level and quality is good. what is the possible reason of this situation?

when i check the trace, the paging is sending but the ms doesnt reply it.

please help

check the paging kpi's. I think you need to divide your LAC area.Customers miss the paging messages beacuse of the more paging trafic.:handshake