Originally Posted by
Dubai Stu
It is not Cingular it is the roaming carrier. They don't release the phone from the system when it is switched off. As a matter of fact, at this year's Gitex (the Middle East's largest tech show), they were actively demonstrating technology aimed at enhancing roaming revenue by increasing the time your phone remains registered on the roaming network and using a software trick that would slow your phone down on registering on a competing carrier.
Under this approach, if you landed at Frankfurt, powered your phone back up for one call to tell your wife that you made your connection, and then shut it down and boarded at plane to the US, you'd be paying these roaming rates until you powered your phone back up in the US.
As annoying as it is, you need to either disable your voicemail or hardforward (e.g. not conditional) all calls to voicemail. If you let the system send it to voicemail if you don't answer, you will hugely increase your roaming bill.
This is another reason why I use a roaming SIM when traveling. They have written a special algorithm to send calls to voicemail that is not dependent on a conditional call forward.
I see. That makes sense. If the VLR keeps reporting you as active even though you aren't, you will indeed stay registered until you show up elsewhere and calls will come through. An unconditional divert seems as the best way to go considering you can set those while roaming at no charge. One just has to remember to do it!
Something different but with the same goal (roaming revenue) happened to me quite some time ago. I've always wondered how it was possible.
Back in ancient history, I was in Prague using an Omnipoint SIM in a Motorola L7089 (should give you an idea of how long ago this was!) For some reason, if the phone registered on Radiomobil, I no longer could see Eurotel in network scans! The reverse was not true. The same thing happened with a Nokia 6150 I was carrying as well. The only way to get Eurotel back was to carry the phone into the metro, set manual network select, and manually select Eurotel upon exiting.
To this day, I have no idea how they did it nor have I ever seen anything like it anywhere else. I suppose it could've been a bug but I always believed it was a way to keep roamers locked in.
What SIM do you use for roaming? I have a post-paid HKCSL SIM that I keep for visits to places where T-Mo charges $4.99/minute but would rather use something better. I've had it for forever so simply haven't gotten rid of it out of inertia.