Re: NetworkManager-MobileBroadband and network choossing

[Dan Williams <dcbw redhat com>]

On Wed, 2007-12-12 at 15:09 +0100, Tomasz Torcz wrote:
> Hi,
> 
> from
> http://fedoraproject.org/wiki/Features/NetworkManager-MobileBroadband :
> 
> # scanning for available cellular networks (GSM only)
> # selection of a cellular network (GSM only)
> # show signal strength of currently connected cellular network
> 
>  Which strikes me as odd. GSM networks aren't like Wi-Fi, user very very
> seldom has to choose one. In fact, choosing GSM network is very corner
> case, only close to country borders. In this situation foreign GSM

Not really; in the US for example T-Mobile has coverage on the coasts,
but not much in the middle.  There are plenty of times that when roaming
even in the US I've needed to pick which carrier I wanted to use on my
phone.  You can certainly automatically pick one that will probably be a
good choice, but when dealing with a system that has the potential to
bill you shedloads of $$$ if you make the wrong choice, we have to err
on the side of caution.  You'll definitely have to pick the
carrier-of-choice when setting up the GSM connection, but you probably
won't need to change that much later on.

That said, NM won't be scanning for GSM networks like it scans for wifi
networks.  I don't think anyone is 100% sure how it's going to work
UI-wise, but GSM scanning certainly takes a really long amount of time
and isn't something that can be done in-band.

> network can be stronger (signal strenth wise) than local one, and user 
> has to manually switch to one of national networks to avoid roaming
> charges. It at least was true some 10 years ago, I don't know how it's 
> handled now and how data connections are billed.

That's the problem; there's no way to know the billing, so we have to
ensure that the GSM part is 100% under the user's control.  We may be
able to offer the user roaming guards or something like that to have NM
kill the connection if the home network is no longer available.

>   In short, indicator for current strongest available GSM signal would be nice.
> Displaying all available networks won't. And would unnecessaty clutter
> interface.

Definitely agreed.  There won't be a GSM network list like there is a
list of WiFi APs.  You'll have to pick a network when setting up the
connection for now if that can't be determined from your SIM directly.

Dan