Re: RFC: API for Neighbouring Cell Info

[Denis Kenzior <denkenz@gmail.com>]

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Hi Aki,

> > Your feedback is highly appreciated, especially from those who plan to
> > use this information for location purposes.
> 
> I think the pattern you use here is wrong. This needs to be a method
> call; a signal won't work. The measurement data is constantly changing,
> and you don't want a constant stream of PropertyChanged() signals.
> 
> So I think something like this instead:
> 
> GetNeighborCells() -> a{sv}, aa{sv}

How is this information obtained from the modem? Is the modem polled? Does it 
signal this data as it changes?  Honestly I don't like either approach, the 
Agent pattern would be a much better fit here.  This would allow us to specify 
the polling/update interval and stop neighbor cell updates when no one is 
interested in them.

> > Once there is agreement on the API we can discuss whether it makes
> > sense to add some skeleton support in the oFono core or leave it to
> > each individual modem plugin to implement the DBUS service in its
> > entire.
> 
> I think it's reasonable to assume that most modems support this. There
> is a standard to follow, and at least isimodem will have a driver for
> it. So I would make it a proper atom from the beginning.

I'd like to see the low level driver API proposal first.  The Nokia isimodem 
interface is actually quite sane, AT command modems are usually not so...  If 
we make this into a proper atom we have to make this work for all hardware 
from the beginning.

> Other comments on the interface:
> > Properties boolean Enabled [readwrite]
> >
> > 			Boolean representing whether the interface provides
> > 			neighbouring cell information.
> 
> This is useless. If a modem driver doesn't support neighbor cell info,
> it won't registered a driver and the interface just doesn't show up.

Being able to turn this capability off is useful.  If there are no consumers, 
then these types of notifications should be turned off to save power / wakeups.

Regards,
-Denis