Telit LE910 failing to find network

[Aleksander Morgado]

Hey Kelvin,

>
> I'm working with a Telit LE910 modem for which ModemManager is constantly
> looping unable to find a network:
> Jul 17 08:05:45 linaro-gnome ModemManager[10429]: <debug> Running
> registration checks (CS: 'yes', PS: 'yes', EPS: 'no')
> Jul 17 08:05:45 linaro-gnome ModemManager[10429]: <debug> (ttyUSB8) device
> open count is 2 (open)
> Jul 17 08:05:45 linaro-gnome ModemManager[10429]: <debug> (ttyUSB8): -->
> 'AT+CREG?<CR>'
> Jul 17 08:05:45 linaro-gnome ModemManager[10429]: <debug> (ttyUSB8): <--
> '<CR><LF>+CREG: 2,2<CR><LF><CR><LF>OK<CR><LF>'
> Jul 17 08:05:45 linaro-gnome ModemManager[10429]: <debug> (ttyUSB8) device
> open count is 3 (open)
> Jul 17 08:05:45 linaro-gnome ModemManager[10429]: <debug> (ttyUSB8) device
> open count is 2 (close)
> Jul 17 08:05:45 linaro-gnome ModemManager[10429]: <debug> (ttyUSB8): -->
> 'AT+CGREG?<CR>'
> Jul 17 08:05:45 linaro-gnome ModemManager[10429]: <debug> (ttyUSB8): <--
> '<CR><LF>+CGREG: 2,2<CR><LF><CR><LF>OK<CR><LF>'
> Jul 17 08:05:45 linaro-gnome ModemManager[10429]: <debug> (ttyUSB8) device
> open count is 1 (close)
> Jul 17 08:05:45 linaro-gnome ModemManager[10429]: <debug> Modem not yet
> registered in a 3GPP network... will recheck soon
>
>
> Scanning for networks there are plenty available, and I have tried SIM cards
> for both EE and O2:
>
> sudo mmcli -m 1 --3gpp-scan --timeout=300
>
> Found 11 networks:
> 23410 - O2 - UK (gsm, available)
> 23415 - vodafone UK (umts, available)
> 23415 - vodafone UK (lte, available)
> 23410 - O2 - UK (lte, available)
> 23415 - vodafone UK (gsm, available)
> 23430 - EE (gsm, available)
> 23410 - O2 - UK (umts, available)
> 23420 - 3 UK (umts, available)
> 23430 - EE (umts, available)
> 23420 - 3 UK (lte, available)
> 23430 - EE (lte, available)
>


The 3GPP module should by default auto-register in the best network it
finds. When using a SIM card for a provider for which there is a real
network available, that should happen instantly, not sure why it's not
happening here.

Can you try to to explicitly request the home connection with mmcli
--3gpp-register-home?

Also, can you try to register in a specific network with
--3gpp-register-in-operator=[MCCMNC] ?

> Is the "EPS supported: No" relevant? The LE910 supports 2G, 3G, 4G.
>

Since ModemManager 1.6.x we enable by default registration checks in
the EPS (LTE) network, it was disabled by default in previous
releases.

> This is running on an embedded ARM device with a fairly old Ubuntu -
> ModemManager was on 1.2.0. I've tried upgrading to 1.4.0 and the behaviour
> is the same.
>

Oh, please update to MM 1.6.x and retry, please. MM 1.4.x is quite
old, and MM 1.2.x is veeeeeery old. The MM 1.6.x release also comes
with a Telit plugin, not available in earlier releases.

> A bit more mmcli info below. Any hints would be much appreciated.
>
> Many thanks,
> Kelvin.
>
>
> /org/freedesktop/ModemManager1/Modem/1 (device id
> '09c17ce0710e6316d160278ddd03f542021ac6ad')
>   -------------------------
>   Hardware | manufacturer: 'Telit'
>   | model: 'LE910-EUG'
>   | revision: '17.00.523'
>   | supported: 'gsm-umts, lte'
>   | current: 'gsm-umts, lte'
>   | equipment id: '359852053548609'
>   -------------------------
>   System | device:
> '/sys/devices/f9400000.ssusb/f9400000.dwc3/xhci-hcd.0.auto/usb1/1-2/1-2.1'
>   | drivers: 'option1'
>   | plugin: 'Generic'
>   | primary port: 'ttyUSB8'
>   | ports: 'ttyUSB8 (at)'

Is this supposed to be a single-TTY modem?

>   -------------------------
>   Numbers | own : 'unknown'
>   -------------------------
>   Status | lock: 'none'
>   | unlock retries: 'unknown'
>   | state: 'searching'
>   | power state: 'on'
>   | access tech: 'unknown'
>   | signal quality: '0' (cached)
>   -------------------------
>   Modes | supported: 'allowed: 2g, 3g, 4g; preferred: none'
>   | current: 'allowed: 2g, 3g, 4g; preferred: none'
>   -------------------------
>   Bands | supported: 'unknown'
>   | current: 'unknown'
>   -------------------------
>   IP | supported: 'ipv4, ipv6, ipv4v6'
>   -------------------------
>   3GPP | imei: '359852053548609'
>   | enabled locks: 'none'
>   | operator id: 'unknown'
>   | operator name: 'unknown'
>   | subscription: 'unknown'
>   | registration: 'searching'
>   -------------------------
>   SIM | path: '/org/freedesktop/ModemManager1/SIM/0'
>
>   -------------------------
>   Bearers | paths: 'none'
>
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>



-- 
Aleksander
https://aleksander.es