Subject: RE: [Simple] Comment to data model and RPID regarding <device> element

From: "Ringel, Rick" <[email-masked]>
Date: Sun, 13 Mar 2005 13:48:51 -0700

All,

For what it is worth, SIP devices may have softkeys.  I understand this
may have no impact to your discussion (I only have time for bits and
pieces), but when one tries to categorize the 'most distinctive
elements' of a device, the soft-key capability is worthy of your
consideration.

SIP phones with display/softkey features are somewhere between numeric
keypads and QWERTY keyboards.

-Rick Ringel 

-----Original Message-----
From: [email-masked] [mailto:[email-masked]] On Behalf
Of Henning Schulzrinne
Sent: Sunday, March 13, 2005 1:04 PM
To: [email-masked]
Cc: [email-masked]; [email-masked]; [email-masked]
Subject: Re: [Simple] Comment to data model and RPID regarding <device>
element

[email-masked] wrote:
> Hi,
> 
> I agree with Henning that mobile vs. fixed, screen size and keyboard 
> are the most distinctive elements of a device. I suppose it might be 
> possible to distinguish between the device types based on these.
> 
> LAPTOP - MOBILE - "LARGE" SCREEN - "QWERTY" KEYBOARD
> 
> CELLPHONE/PDA - MOBILE - "SMALL" SCREEN - "NUMERIC" KEYBOARD
> 
> BLACKPHONE - FIXED - NO SCREEN - "NUMERIC" KEYPAD
> 
> DESKTOP - FIXED - "LARGE" SCREEN - "QWERTY" KEYBOARD
> 
> I'm not sure if you can express the differences between all the other 
> devices proposed by Aki (and Dave :-), but I suppose this would cover 
> most of the devices where e.g. SIP UAs wil be found. Also, I'm not 
> sure how useful the difference of knowing between for instance cell 
> phone and PDA or desktop PC and Playstation 2 would be for the 
> watcher.

That's pretty much what I had in mind. I'd much rather label the
properties, so that we don't have to worry about various permutations in
the future. Just as an example, some of the SIP phones are

    FIXED
    SMALL B/W SCREEN
    NUMERIC KEYPAD

and may, in the future, be

    FIXED
    MID-SIZED COLOR SCREEN
    SMALL QWERTY KEYPAD

Labeling both as 'black phone' is not very helpful, but they are not
really PDAs or laptops, either.

I'd suggest the following rough division:

    Screen: small (< 400,000 pixels), mid-sized (< 700,000), large
      or just convey the pixel count in Kpixels, as well as whether the
screen is monochrome (< 256 shades of gray); grayscale or color.

    Keyboard: numeric, hunt-and-peck (Treo/Blackberry-like), regular

    Mobility: mobile, portable (e.g., iMac or Xbox), fixed

Obviously, there are better names for these things. If the watcher
recognizes standard combinations of these to show a laptop icon or a PDA
icon, that's a UI decision.

Henning

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---

From: "Zisimopoulos, Haris, Group R & D" <[email-masked]>
Date: Thu, 10 Mar 2005 22:58:23 -0000

I agree with Aki. We have gone through the same discussion in OMA, when we were defining the <device> really is and how it is determined what its "limits" are.
IMHO it is not very important to give an accurate definition as there are so many combinations that it may be impossible to derive what the type of the device from the capabilities (eg is a laptop with a UMTS/GPRS datacard really a laptop or mobile phone?,also my current phone may potentially have more processing power than my old computer at home). 
Therefore we can have a <type> token list element with maybe freetext as well (to allow future extensibility) and let the "device" PUBLISH what it "feels" it is. 
It seems simpler to me...

Best regards,
Haris

Haris Zisimopoulos
Group Research & Development - UK
Vodafone Group Services Ltd

Telephone: +44 (0)7919994709
Facsimile: +44 (0)1635 676147

E-mail: [email-masked]

-----Original Message-----
From: [email-masked] [mailto:[email-masked]]On Behalf
Of Aki Niemi
Sent: 10 March 2005 22:27
To: [email-masked]
Cc: Henning Schulzrinne
Subject: [Simple] Comment to data model and RPID regarding <device>
element

All,

The definition of <device> in the presence data model states that rather 
than have a token identifier that defines what type of device the 
<device> element is describing, this information *could* be reduced from 
device characteristics, such as CPU speed, memory size and screen size.

I believe this design has been motivated by the fear of a combinatorial 
explosion. I.e., there could potentially be a very large number of 
device types, ranging from the mobile phone duct-taped to a laptop to a 
cray supercomputer.

However, I also believe this design is broken. Especially for a device, 
it is extremely difficult to reduce a meaningful representation that is 
reasonably accurate out of these limited characteristics. For example, a 
2,4GHz CPU today could mean a desktop computer, but in not-so-distant 
future, most mobile phones will have CPUs in that class.

I also tried to imagine how many device types there could be and I 
arrived at a list that was not that excessive at all:

laptop
desktop
mobile phone
PDA
HTPC or media PC
blackphone

So my proposal is to add a new element under <device> in RPID called 
<type> with at least the set of registered types above. In addition, 
there would be an "other" type, and a <note> element that either gives 
further information about the device type, or in the case of the "other" 
type, could indicate that indeed this is a PDA duct-taped to a laptop.

Opinions?

Cheers,
Aki

P.S. Apologies for contributing to feature creep at this point in the 
game...

---

From: "Boyer, David G \(Dave\)" <[email-masked]>
Date: Mon, 14 Mar 2005 13:21:59 -0500

Henning,

One propertity that it might make sense to add is voice/audio -
in the same way that the size of a video screen might infulence
the type of video interaction you have, the voice/audio property
of a device may cause the requestor to establish a communications
with a different device.  Wideband or stereo might be required
in some cases.

Dave

> From: [email-masked] 
> [mailto:[email-masked]]On Behalf
> Of Henning Schulzrinne