Originally Posted by
Dubai Stu
In theory you are correct, but if you flip the radio on and off it is not instantaneous. Many cellular companies hold your registration information cached in their system to keep you locked to their network. In 2008, I was at Gitex in Dubai and there were companies exhibiting this equipment. I got burned in Africa when I tried turning my cell phone on for only ten minutes in the morning in ten minutes in the evening to see if messages arrived.
Spend a few minutes googling on the phrase "roamer OR roaming AND capture AND revenue"
When I go down this path, historically people have argued the point with me. I'm only relating my experience.
I find that what you are saying is the norm worldwide base on my experience.
My procedure is to reroute my communications based on my new location before departure and device not turned on in a new location until the local SIM is installed