Tri-band phones seeing different networks

In <1117658920.837279.92170@g14g2000cwa.googlegroups. com> "grum" <graeme@templelocks.net> writes:

>One is a US T-Mobile (locked) Motorolla V180 supplied by my employer.
>It reports available networks as T-Mobile and AT&T.

>The second is a UK Orange (unlocked) SPV C500. It reports available
>networks as Cingular and AT&T.

I think the following should explain it. But if
I'm wrong, I'm sure plenty of people will correct me.

About five years ago Cingular had a physical network presence
in California, and t_mobile had theirs in NY. The two companies
made a handshake to allow each others customers to invisibly
cross-roam when in teh other's area.

In other words, if you were a cingular customer in NYC you'd
be on t-mobile (and vice versa).

The base station in NYC, though, would be putting out
a numerical ID that's associated with t-mobile.

So... if you had a multi band international phone you'd
either see the numerical ID or you'd see "t--mobile", depending
on whether the SIM "knew" the translation.

But... if you purchased a Cingular phone in the NYC
area, it would show "cingular", even though it was
using the t-mobile towers.

Same thing, in reverse, for California. A multi band
international phone over there would either give the
numerical ID or the Cingular name.

This would even be the case, *sometimes*, if you had
a t-mobile phone in Calif.

If the phone was specifically marketed by t-mobile in
California, they'd have programmed the SIM to translate
that Cingular ID number into the name "t-mobile".

But.... other phones wouldn't have that, so they'd
still show Cingular.

Now you've got a t-mobile branded and California
marketed phone, so it's seeing the (cingular) base
ID and is displaying it as t-mobile. The other phones
show the, for want of a better term, cleaner interpretation.

NOTE that this handshake arrangement is being phased
as each company builds out its own network, but
O don't know thje schedule.
--
__________________________________________________ ___
Knowledge may be power, but communications is the key
dannyb@panix.com
[to foil spammers, my address has been double rot-13 encoded]