On Wednesday, June 19, 2002, at 09:58 , Ken Chang wrote:
> in IS-41 first and GSM later, the HPLMN can reject the call
> but direct the calling switch directly to the VPLMN, so that
> the HPLMN can stay away from the voice trunks. if a guy in
> the visited area (not tech term) calls the roaming subscriber:
>
> calling -> called HPLMN
> calling <- called HPLMN (reject, provides forward number) *
> calling => called VPLMN => roaming mobile
>
> - signal
> = voice trunk
> * REDREQ (IS-41 redirect request) or
> resume_call_handling (GSM)
The nice thing about the vanilla call forwarding is that is bypasses the
mobile phone companies roaming surcharges.
The call is forwarded over competitive territory (long distance provider)
In the visited network, the called party is not being charged for the
incoming call.
Also, the technique works in any "home network" not only mobile home
networks. The home network can be a fixed line service, such as the
company providing services to your office. Provided they deploy the
ZEBRA interface to receive a message from the roaming service centre to
be notified of the assignment of temporary local phone numbers whenever
the subscriber shows up in a visited network, even a non-mobile network
can automatically invoke the forwarding service to forward incoming
calls (ie to your office) to the temporary phone number while roaming in
the visited network.
Thus, if the HPLMN overcharges for inbound roaming calls or forwarded
calls, then you may forward permanently and unconditionally to your
office number and have calls forwarded to you from there, competitively
priced.
Alternatively, you may have a premium rate service based 07000 personal
number. The service provider of that service will get a share of the
revenue a caller pays and that share will be sufficient to pay the
forwarding to many destinations and still make a profit. So, you could
print your 07000 number on your business card and have people call you
there instead of your mobile. Then if you are assigned a temporary local
phone number in a visited network, the roaming service centre could
notify the 07000 provider of the temporary number which would then
automatically invoke the forwarding service. The result is that you
don't pay anything for inbound calls, yet you can be reached on a single
number that never changes.
But even if you have to pay for the forwarded leg, using a vanilla
forwarding service routed through a competitive long distance provider
versus direct HPLMN to VPLMN delivery can make the difference between
10p per minute and 1++ GBP per minute.
regards
benjamin
Received on Wed Jun 19 16:36:56 2002