When plugging in a USB modem, i.e. a “surf stick” / internet stick
with a SIM card for mobile broadband, setup should be as simple as
WiFi.  However, a few things are missing in Guix.

First, the manual claims:

 -- Scheme Variable: modem-manager-service-type
     […]
     This service is part of ‘%desktop-services’ (*note Desktop
     Services::).

But it is not part of %desktop-services.  The first attached patch
fixes this oversight.

Now I can type this to get an internet connection:

sudo nmcli connection add type gsm ifname ttyUSB1 apn internet


However, I want to be able to do this setup graphically.  I made a
second patch to propagate iso-codes (for mobile broadband country
selection) and mobile-broadband-provider-selection (for selecting
defaults for providers) in nm-connection-editor
(network-manager-applet) and gnome-control-center.

Propagation is ugly though.  Should I try patching
network-manager-applet instead?  I assume there are other packages
doing such patching that I can imitate.


Now I can configure the modem as Mobile Broadband in a graphical
interface.  I cannot do so in nmtui; I believe this modem setup
feature is not included in nmtui.


However, this is not the whole truth.  Before I can configure
anything, I have to run

sudo ~/usr/sbin/usb_modeswitch -c ~/Downloads/usb-modeswitch-data-20170806/usb_modeswitch.d/12d1:14fe -v 0x12d1 -p 0x14fe

because my modem by default presents itself as a CD containing Windows
drivers and not as a USB modem.  Preferrably, usb-modeswitch and
usb-modeswitch-data would be packaged (as a single package).  I can
try that later this week.

Lastly, there are udev rules in usb-modeswitch, I believe, because on
Debian I do not need to run any command; mode switching happens
automatically when plugging in the USB modem.  I suppose that means
there should also be a usb-modeswitch-service-type extending udev?

Regards,
Florian