Disconnect with non LTE capable provider

[Guido Günther]

On Sun, Feb 09, 2014 at 02:13:43PM +0100, Guido Günther wrote:
> Hi Aleksander,
> On Sun, Feb 09, 2014 at 01:52:08PM +0100, Aleksander Morgado wrote:
> [..snip..] 
> > In order to force this device to 2G/3G-only, therefore we cannot use
> > --set-allowed-modes="2g|3g" because that combination is not supported
> > by the current capabilities. Instead, we actually need to switch
> > current capabilities to "gsm-umts".
> > 
> > Can you try to run the following?
> > 
> > $ sudo mmcli -m 0 --set-current-capabilities="gsm-umts"
> 
> That worked:
> 
> Capabilities:
> |      supported: 'gsm-umts
> |                  lte
> |                  gsm-umts, lte'
> |        current: 'gsm-umts'
> 
> 
> Modes:
> |      supported: 'allowed: 2g; preferred: none
> |                  allowed: 3g; preferred: none
> |                  allowed: 2g, 3g; preferred: none
> |                  allowed: 2g, 3g; preferred: 2g
> |                  allowed: 2g, 3g; preferred: 3g
> |                  allowed: 2g, 3g, 4g; preferred: none'
> |        current: 'allowed: 2g, 3g; preferred: 3g'
> 
> 
> I'll pass some LTE areas next week so I can check if the conection stays
> alive then. Thanks a lot! 

I just lossed the connection (without moving[1]) and saw this in the logs:

Modem /org/freedesktop/ModemManager1/Modem/2: 3GPP Registration state changed (home -> searching)
Modem /org/freedesktop/ModemManager1/Modem/2: 3GPP location updated (MCC: '0', MNC: '0', Location area code: '<removed>', Cell ID: '<removed>')
Modem /org/freedesktop/ModemManager1/Modem/2: access technology changed (lte -> unknown)
Modem /org/freedesktop/ModemManager1/Modem/2: 3GPP location updated (MCC: '0', MNC: '0', Location area code: '0', Cell ID: '0')
Modem /org/freedesktop/ModemManager1/Modem/2: signal quality updated (30) 
Modem /org/freedesktop/ModemManager1/Modem/2: access technology changed (unknown -> umts)

so it seems there was a short switch to LTE although I have this
disabled:

  Hardware |   manufacturer: 'QUALCOMM INCORPORATED'
           |          model: 'ME906E'
           |       revision: '11.234.44.08.00  1  [Apr 25 2013 01:00:00]'
           |      supported: 'gsm-umts
           |                  lte
           |                  gsm-umts, lte'
           |        current: 'gsm-umts'
           |   equipment id: '866714010149192'

  Modes    |      supported: 'allowed: 2g; preferred: none
           |                  allowed: 3g; preferred: none
           |                  allowed: 2g, 3g; preferred: none
           |                  allowed: 2g, 3g; preferred: 2g
           |                  allowed: 2g, 3g; preferred: 3g
           |                  allowed: 2g, 3g, 4g; preferred: none'
           |        current: 'allowed: 2g, 3g; preferred: 3g'

Any ideas what triggers this? 
Cheers,
 -- Guido

[1] the usual special relativity theory disclaimer applies: at least not
    relative the the UMTS/LTE base stations