High SDCCH Traffic in LA Borders

Pix, thanks for the quick answer. My question was related to an increase of SDCCH congestion due to an increae on the PCH blocking, but from you answer, I think the situation is the other way round, the SDCCH congestion limits the resources of the cell, demanding a paging retransmission due to lack of TCH resources to answer that call. As the PCH is answered by the RACH, there wouldn’t be a direct relation, but your answer gave me a new perspective. Thanks.

dear
can ay body help me to solve problem for location update rejection on two country border when trace is been done found there are alot of location update rejection due to message (PLMN is not allowed) or ( network failure),as checked there is raomimg agreement between operator but subscriber is not activate for roaming what is the solution
BR

what are the main perameters to be defined for the handovers of a call originated in a sector of any site which is operating on both 900 as well as 1800 bands(dual band network).At what time and which situation the handovers should happen.

hello,

This is definitely not my area of expertise, but I would say that the PLMN is defined as “Not allowed” in the SIM, yes if the SIM eventually tries to access that PLMN, the HLR accepts it.

Strong chances are that I’m wrong though… IMO, the best option is to read the 3GPP, and check what it means when a PLMN is “not allowed” in a SIM. Can a SIM still attempts an IMSI ATTACH towards this particular PLMN ?

Regards,
Pix

Dear Pix

1. I have read 3GPP & ETSI documentations 🙂 around 300MB standards in this subject. and everything is OK on standards. But in real, the standards rules are not obeyed by the equipments !!! and this is much strange for me.

2. Yes, it(they) can do IMSI attach. no problem. in deed after a minute everything becomes OK !

3. If any guy works in a Mobile Network in country that there are more than 1 operator in same cities and these Operators don’t have Raming agreement with each other, please inform me. I may ask a question from him/her that will help me very much.

4.the story is as below: (Excuse for long declaration in the stroy):
there is 3 networks in the country(Op1,Op2,Op3). The problem is that: The MS of Op1 tries to Location update on other ones hugely !!! even they have coverage in the area.
I check all details, detailed information, standards,…… I found many things and two of them are as below:

1. When a MS comes into coverage or in turning on;(in automatic network selection); first checks for RPLMN (and then HPLMN asap); then HPLMN, then EHPLMN, then allowed prioritized, then sorting Quality and power (all stages: omitting Forbidden PLMNs)

2. When a network respond “LU reject due to PLMN not allowed” in response to Location update request; then that PLMN will be registered in the “Forbidden PLMN list ” of MS (except HPLMN).
this PLMN can be cleared just when the MS goes off/on or after long period of time or fulling the buffer (that I think it has capacity for 4 PLMNs).
in this case the MS won’t request that PLMN again for location update.

I said standard notes, but what happens in here is:
related to No.1 : The MS (SIM of op1) requests other networks (Op2, Op3) in presence of good power level of op1 ARFCNs and those sites are Ok too. there is no try on them!!!
related to No.2: the SIM of op1 tries on op2 and op3 and recieves “LU rejected due to PLMN not allowed”, but after some seconds it requests these networks again for LU !!!!! (maybe op2 or op3 are not written in forbidden list OR forbidden list can be cleared soon !!!!)

This subject has brought huge amount of signalling traffic to BSC signallings of op2 and op3.
Really I’m amazed, as I have check everything in stadards and everything must be OK; but the GSM rules and standards are not obeyed and performed by MSs and SIMs.

Why ??????
and declaration or explain or answer can be benefit for me. Really I have tested and checked everything I knew and was possible to be checked.

Dear Pix

Yes, This is very much amazing and a challenge for mobile networks and standards.
This subject is directly related to NSS, Core and SIM-Card mans. but the effect of it impact the Radio/BSS parts that makes the issue complicated.
—
We perfom checking with using following lines: (and combine, compare, evaluate all them toghetehr)
1. Using Protocol Analyzer and checking signalling over BSC/MSC in MAP,BSAP,… layer AND checking the cause, response, … of LU request, Roaming request,…
2. Performing Driver Test with some SIMs and having Quality, Scanning, Signalling (Layer2,3,events,…) in attention
3. Checking SIM Cards status with simple readers.
—
So you see that everything is checked and all of them are compared with recommendations and standards (I was forced to read around 300MB docuemnts and standards)
—
* again I say that, SIM-cards of Op1 must be rejected by Op2 or Op3 as they don’t have any roaming with eachother in neither same place or other places.
The problem is that:
(1)Why they are rejected in the registration of their own HPLMN!!!! sometimes ???
(2) why in presence of Op1 good power and service, they send request to Op2 and Op3 ???
(3) Why they try again and request again from Op2 and Op3 after some minutes that they had recieved rejection answer from them once !! ???
These three issues deny any standard rule !!!
—

* May be this subject is a big but hidden problem of some operators in the world. The guys who work in countries which 2 or 3 operators cover same areas without having roaming agreement, may suffer from it or have solution.
—

Really my knowledge in this issue has come under question 🙂

riverstreamer [gmail]

Oooh, i forgot about this.

Riverstream, any news ?

Bireswar: there should be paging retransmission… The MSC didn’t got any reply to its first paging, so it will send a second one.

Riverstream,

That’s too bad about you not working in telecoms anymore. But at least, you’re in europe. I hope you’re fine there.

I’ll keep thinking about the roaming problem, I’m sure one day I’ll get to it… eventually 🙂