[MM - plugin] Network mode change support on Netgear AirCard 340u.

[Aleksander Morgado]

On Mon, Apr 4, 2016 at 8:56 AM, Jarosław Bielski <bielski.j at gmail.com> wrote:
>
> thanks for your quick answer. As you have written the modem has set
> capabilities gsm-umts and lte by default. I have changed current
> capabilities to gsm-umts only and after that there is available a set of 6
> mode combination to set. Unfortunately some combination is not allowed to
> set (setting 2g only causes Core.Unsupported error) and if modem is
> configured to use 2g|3g only the device still reports that it is using 4g
> connection (modem has small LCD showing current modem/connection status). I
> am now confused about setting current network mode on the interface.
>

Could you gather debug ModemManager logs while the capabilities are
set to "gsm-umts" only? Get the modem registered in the network and
connected, while getting the logs, please. We should see what the
modem replied in each of the commands we send.

> A person from AT&T support gives me a feedback that the network mode might
> be changed using AT!BAND command, I have found that another command
> AT!SELRAT might be used to manage that (from MM Sierra legacy plugin).
> Unfortunately the 340u modem is not supported by Sierra legacy plugin, so I
> had asked you how to patch the plugin (allow to send AT command from
> application or overwrite set_allowed_modes method) to make setting mode
> working with Netgear modem.
>

You could do that, yes, I mean it's totally possible to override some
of the steps implemented in QMI mode and use AT commands for those,
just look at how the Cinterion plugin provides AT-based GPS location
gathering in the QMI modem. But, I'd advise against doing that, if
there's any issue in the QMI implementation we should try to fix and
handle it, not provide vendor-specific overrides.

-- 
Aleksander
https://aleksander.es