Sorry for the delayed answer. Just a follow up to Rawand's response.
For Roaming to work there needs to be a Roaming Agreement between the HPLMN and the VPLMN.
This will help to ensure that the Service Level Agreement can be fulfilled and will ensure that
Billing information can be extracted / processed and sent to the relevant Mobile / Wireline operator (CSP). Refer to TAP3 / RAP processes.
With GSM (and 3G, 4G, etc..) the HLR / HSS / UDC / etc.. is updated when there is a change of Location.
This is required so that the HPLMN can signal and route calls. At the time of writing (2019) most CSPs are using CAMEL, e.g. Phase 2, as a Feature to help with Telephony PrePaid services. The VPLMN and the HPLMN will
as a minimum be required to support CAP V2 and MAP V3. The MSC/VLR/gsmSSF and the STP layer will need to be
able to process IMSI and MSISDN.
IMSI analysis and MSISDN digit decoding are Features that MSC/VLR/gsmSSF supports.
VBR/ Wallis Dudhnath
CAP - CAMEL application part
CSP - Communication Service Provider
MAP - Mobile Application Part
rawand - 20th May 2012 (09:06 GMT)
dear is didn't get your poing but for making a success location update like if you roamer A and what to perform a success LU under B in B side you IMSI translation with E164 & E214 need to be added in MSCs STPs and SCCP carrier in A side will added B E164 in their HLR for camel their E164 and VMSC GTs need to be added too in IN side
Gerinc - 22nd March 2012 (16:37 GMT)
Hello to all in forum,
May somebody say me what could be the basic verifications needed to do in Operator A when a subscriber of Operator A is in roaming in Operator B (in other country) if Subcriber A is not making Location Update.
For roamers of Operator B to roam in Operator A (I would be A operator) I need to verify the IMSIS analysis and Global title data, but the opposite event how would be?
I think to verify with signaling provider, but in MSC of my side is needed to verify something?