22 january 1997 Ottawa Canada
Some carriers and i think Mobilink canada do it, have their
networks report the arrival of roamers to the person's home
switch so your switch will know you were last seen in cell site
so and so.
So when someone calls your cellular number, the network looks for
you in that cell site and then widens the search.
This is called automatic call delivery.  It is the most seamless
way to roam.
Not sure if the networks exchange information as to your status
on your home network or not e.g. stolen, fraud etc.
If they did, it would be one good way to eliminate fraudulent
phone use.
the much touted follow me roaming has the switch you are on
advise your home switch you may be reached at a special
dynamically allocated telephone number so your home switch call
forwards your line to that number but for just one day.
 The forwarding is renewed the first time you do a follow me roam
 star function the next day too.
Oh the joys of cellular eh?
... Answers: $1, Short: $5, Correct: $25, dumb looks are still free.
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