Re: WIFI Direct

[Dan Williams <dcbw redhat com>]

On Wed, 2009-11-18 at 10:04 +0000, Jue Yang wrote:
> Hi,
>  
> I am going to develop WIFI Direct on NM 0.7.0, but still a fresh to
> NM.
> I wonder if someone can give me some suggestions or whether NM group
> may put WIFI Direct on schedule?

We talked about it (well, me and many of the other people involved in
Linux wireless) at the Wireless Summit in September.  We'll first need
support for it in wpa_supplicant before NetworkManager can use it.
Next, we'll need to be able to identify WiFi Direct APs (which we can do
based on beacon IEs or IIRC the standard-format SSID of the peer) and
show them to the user in the menu or otherwise.

Basically, NM should be able (with wpa_supplicant) to set up the
connection to the WiFi Direct peer, and then outside NM, the service
discovery protocols can take over and the user can do whatever they want
(download pictures from the camera, upload them to the photo frame,
etc).

But the majority of the work will be in wpa_supplicant and the kernel
drivers I expect.  Note that for most of the current drivers, connecting
to a WiFi Direct peer will probably terminate your current connection,
because the WiFi Direct peer will likely be on a different channel than
your access point.  This is the same situation with Bluetooth 3 and so
we should probably handle it the same way.

Now if we want NM to be the wifi peer that say a camera can connect to,
we'll still need support for this in the kernel drivers and
wpa_supplicant before we can do this.  Then I'd think it would be a
variation on the "create new wifi network" that NM already supports, but
with some additional capabilities.

I think to start with, you should write a few paragraphs about some
target use-cases and how the user would conenct.  Something like:

"Mary wants to send pictures to her picture frame.  Both her laptop
(running NetworkManager) and her picture frame support WiFi Direct.
Mary opens the applet menu and sees here picture frame in the list of
wifi networks.  She clicks on the picture frame, waits a few seconds for
the connection to be set up, and then her photo manager alerts her that
a  new photo frame is available, and would she like to send her newest
pictures to it?"

We want to get some detailed ideas of how the user interaction will
proceed before we start doing most of the NetworkManager work.  That way
we can try to anticipate some of the problems that users might encounter
when using it.

Are there other use-cases you can think of?  We should pick 3 or 4
use-cases, write them up, and then make sure that the solution we pick
for NetworkManager enables all of them.

Dan