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.
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.