Re: SAT support in oFono

[Marcel Holtmann <marcel@holtmann.org>]

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Hi Lasse,

> > > I am checking what is the level of SAT/STK support in ofono and have a couple of questions. The current implementation contains support for basic STK commands, like menus, inputs, calls, sms and so on. In TODO, there is only REFRESH command on the list.
> > > 
> > > Is there plans or ideas to extend the support in oFono Core with more complex STK features like (3GPP TS 31.111):
> > > - Call control by USIM
> > > - MO SMS Control by USIM
> > 
> > Let us set aside the the merits of the use cases for these features for
> > the moment ;)  Implementing Call control by USIM is fairly
> > straightforward to do in the core.  However, no modem manufacturer
> > currently allows us to have full control over this feature.  It is
> > implemented in the firmware and every vendor does this differently.  So
> > for now support of this feature is in the realm of the modem driver.
> > 
> okay, so assuming this is how it is going stay. Even modem handles
> these, ofono should deliver possible AlphaId SIM may give in a response
> to call control envelope. I did not see if this is implemented. Or is it
> dropped since it is not tested in GCF..

show us modem hardware where this is needed. At some point we just had
to be realistic here in what can be tested with real hardware. And thus
is really required to be supported and what makes sense in a smartphone
environment.

> > > - BIP (Bearer independent protocol), including commands like OPEN CHANNEL, CLOSE CHANNEL, SEND/RECEIVE DATA
> BIP is on many operators' wish list of supported SAT features. Even it
> is optional in 3GPP, some market areas will probably require BIP. I
> don't have an example to give right now.

I think the important phrase is "wish list". So far nobody could really
showed me the exact use case for BIP. I am actually really interested in
understanding what the operators wanna use it for. I prefer to have hard
facts here and not just "wish list" and "probably". If this is not a
requirement for certification and the operator is not actually using
such a feature at all, then why bother. Feel free to convince me
otherwise here.

While we can certainly look into supporting BIP at some point, but from
where I am standing it is pretty clear; first get all mandatory STK
features sorted out, before trying to work on optional ones.

> > > - Extend support in PROVIDE LOCAL INFO
> > 
> > What support are you looking for?  Most of the information that is asked
> > by provide local info is implemented in the modem firmware.  We have
> > only included support for items which are not covered by the firmware.
> > 
> If aiming GCF approval support should contain: IMEI, location info,
> network measurements&BCCH channel list, timing advance, access
> technology, IMEISV, Inter-frequency UTRAN measurements. As you said
> these are often handled by modem, but isn't possible that modem can be
> configured in a way it leaves the full control of SAT to the host?
> Although certain AT command based modems would require proprietary
> commands to fetch all the needed information. So in that sense it is
> more logical for modem to handle these commands what requires low level
> interfaces.

What we have seen so far is that all of these are handled by the modem.
If the modem has all information available, then why bother waking up
the host CPU for this. It does make a lot of sense to keep the host CPU
asleep if possible. I am pretty pragmatic here; if we have to support a
modem that does not handle these, then we have to do it.

So if you have more information about other modem types, please let us
know. And patches are always welcome.

> > > - EVENT DOWNLOAD / SET UP EVENT LIST
> > > 
> > 
> > Again, which ones are you looking for?  oFono explicitly ignores the
> > following two events as these make no sense in the smartphone context:
> > 
> > - Idle Screen Available
> > - User Activity
> > 
> It looks like  Idle Screen Available and User Activity & User Activity
> are mandatory features in 3GPP TS 31.124, chapter 3.4 Applicability
> table. Rest of the sub-features are listed there. 

Don't they depend on the STK profile that you are using?

Regards

Marcel