What is the principle to choose network for international roaming??

The phone scans all networks
if the strongest is 1800, it will take the 1800 and vice versa
"Alistair Gale" <AlistairMUNGED@caribsurf.com> schreef in bericht
news:b8hh81phn350leoq203mvle037ic1jt7v5@4ax.com...
> On Mon, 16 May 2005 06:54:36 -0700, Joseph <JoeOfSeattle@yahoo.com>
> wrote:
>
> >On Mon, 16 May 2005 08:43:24 GMT, "KoRn via CellPhoneKB.com"
> ><forum@nospam.CellPhoneKB.com> wrote:
> >
> >>When my mobile(triband) switch on in another country and my home network
> >>(1800) has an agreement with more than one service
provider(900/1800/1900)
> >>in that country. What is the principle that my mobile choose a network
> >>(900/1800/1900). In case that my mobile set to automatic select network.
> >
> >What's your question? If you have your phone set to automatic it will
> >choose the first strong network that your home carrier has an
> >agreement with.
>
> Assuming my carrier has roaming agreements with several carriers in
> the destination -- How does the phone/SIM select the network?
>
> Say some carriers are 900 only, some are 1800 only.
>
> If I last used my phone on a 900 network before arriving will it
> search 900 first? And hence select a carrier on 900?
>
> Or Does the phone scan all bands and pick the strongest signal?
>
> Is there something corresponding to the "preferred roaming list" in
> TDMA where my home network can "guide" the phones choice of network
> even if the signal strength is not the best? Would this be on the SIM
> or loaded into the phone?
>
> --
> alistair
>
>
>
>
>

"Alistair Gale" <AlistairMUNGED@caribsurf.com> schreef in bericht
news:b8hh81phn350leoq203mvle037ic1jt7v5@4ax.com...
> On Mon, 16 May 2005 06:54:36 -0700, Joseph <JoeOfSeattle@yahoo.com>
> wrote:
>
> >On Mon, 16 May 2005 08:43:24 GMT, "KoRn via CellPhoneKB.com"
> ><forum@nospam.CellPhoneKB.com> wrote:
> >
> >>When my mobile(triband) switch on in another country and my home network
> >>(1800) has an agreement with more than one service provider(900/1800/1900)
> >>in that country. What is the principle that my mobile choose a network
> >>(900/1800/1900). In case that my mobile set to automatic select network.
> >
> >What's your question? If you have your phone set to automatic it will
> >choose the first strong network that your home carrier has an
> >agreement with.
>
> Assuming my carrier has roaming agreements with several carriers in
> the destination -- How does the phone/SIM select the network?
>
> Say some carriers are 900 only, some are 1800 only.
>
> If I last used my phone on a 900 network before arriving will it
> search 900 first? And hence select a carrier on 900?
>
> Or Does the phone scan all bands and pick the strongest signal?
>
> Is there something corresponding to the "preferred roaming list" in
> TDMA where my home network can "guide" the phones choice of network
> even if the signal strength is not the best? Would this be on the SIM
> or loaded into the phone?


Typically roaming preferences are specied on recent SIM's.

I'm a Belgian "BASE" network subscriber (www.base.be, Belgium, wholely owned by
KPN Holland www.kpn.com)

Whenever I cross the border into Holland my GSM phone
immediately switches to
KPN cellular. If for some reason I loose the KPN GSM coverage
my phone switches to another GSM network (Holland has a total of 5,
all covering 99% of the country, quite simple in a small and flat country) -
but as soon I'm back in reach of a KPN cell I'm back on KPN.

This "preferred GSM" network selection when roaming is
completely managed by my SIM - there is just one simple rule:
the SIM dictates what the preferred network is, and will try to
to roam on that network.

I once used a Vodafone SIM: when roaming it switched to the foreign
Vodafone network and kept trying to keep that connection alive
(same phone, full retail without an operator lock)