Re: Telit LE910V1 - LTE only modem

[Lukasz Nowak <lnowak.tyco@gmail.com>]

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Hi Denis,

I investigated this further today. The Telit modem exposes two interfaces AT commands and QMI.
What you are describing matches what the AT interface reports:
- modem powers on already registered to the network with 5 contexts, and one of them is active

However, the QMI interface is quite different. None of the "profiles" as QMI calls them is active.
The user needs to explicitly activate one of them with a "start network" command. Without that,
the modem's data service (WDS) appears off-line.

For now, I left it the way the original qmimodem code works - the user provides an APN.
This works fine - the QMI "start network" command uses the user's entry from a context, and
the modem is happy with that.

As an enhancement the wds-get-default-settings command could be used to pre-fill the context
with APN, IP type and auth. But the ofono gprs context still needs to be activated in order
to send the QMI "start network" command.

Lukasz



On 21/03/17 18:57, Denis Kenzior wrote:
> Hi Lukasz,
> 
>> I am still a little bit confused about ofono_gprs_cid_activated(). As far as I can see only atmodem calls it. No other driver does that.
> 
> That's because only the ublox devices have been properly enabled for LTE :)
> 
>> I am not sure if a context is automatically created. I can see that the sim card has a few profiles, and the user can select which APN to use, start/stop ip network, etc.
> 
> Yes, that's how LTE works.  An initial context (default bearer) is always activated on LTE.  The device can provide an initial attach APN (see doc/lte-api.txt) which is used to tell the modem which APN to attach to by default.  From what I recall, the device can provide an empty APN (in which case the network assigns one).
> 
> The default bearer varies by the carrier.  Some use it for IMS, some use it for the internet context.  So the modem/firmware behavior is often tweaked for a particular carrier.  Some modems might not report the default context at all in which case the device acts more like a 3G modem than an lte one.
> 
> Regards,
> -Denis