W3C home > Mailing lists > Public > public-poiwg@w3.org > December 2010

Re: Realtime use-case's

From: Christine Perey <cperey@perey.com>
Date: Mon, 13 Dec 2010 20:14:06 +0100
Message-ID: <4D06707E.6020902@perey.com>
To: "Seiler, Karl" <karl.seiler@navteq.com>
CC: Thomas Wrobel <darkflame@gmail.com>, "public-poiwg@w3.org" <public-poiwg@w3.org>
Hi Karl,

I think your statements are basically in support of not making a 
distinction at least at the data format/definitions level between real 
time and non-real time use cases.

Did I understand correctly?


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On 12/13/10 7:30 PM, Seiler, Karl wrote:
> Historical experience (no pun intended) has shown that any attempts to separate real-time from non-real-time definitions suffer from the attrition of the world speeding-up-all-things.
> What was considered static is now updated more frequently.
> Change happens when it happens and not on fixed cycles.
> Everything is real-time just some more so than others.
> _______________________________
> Karl Seiler
> Director Location Technology&  Services
> NAVTEQ - Chicago
> (T)  +312-894-7231
> (M) +312-375-5932
> www.navteq.com
> -----Original Message-----
> From: public-poiwg-request@w3.org [mailto:public-poiwg-request@w3.org] On Behalf Of Thomas Wrobel
> Sent: Saturday, December 11, 2010 1:23 PM
> To: cperey@perey.com
> Cc: public-poiwg@w3.org
> Subject: Re: Realtime use-case's
> Those all seem reasonable statements to me.
> I can't see of any flaws and it seems to cover the more specific examples.
> I think the key is, as much as possible, for the data being submitted
> (in both the play and create) examples to be the same sort of data
> being read in the guide example. So the data creation, data update,
> and data viewing can all be done with the minimum of transformations
> or conversions by both clients and servers.
> As far as the data itself goes, yes, I really don't see any special
> requirements realtime introduces to the formatting. Although a few
> minor things would be beneficial - for example, timestamps of the last
> time the data was updated. (if its a remotely linked mesh, the client
> shouldn't have to re-download unless its strictly needed). So maybe in
> a few case's realtime would add some weight to the need for specific
> fields in the POI.
> I can also see realtime later  influencing some of the design of the
> spec though by way of protocol.
> I think it was mentioned earlier, for example, that if the data is to
> be transmitted in a non-html format, you cant relay on a xml style
> hierarchy being present. This could influence how you would position
> one (virtual) object with respect to another. In xml it might make
> sense to have one as a child of the other, and hence when one moves,
> the client knows to move the children.
> However, this becomes impossible if the two bits of data are from
> different sources not within the same file or stream. So in that case,
> an ID system of some sort would have to be used. (So maybe one POI
> could be positioned relative to a URI of another??)
> This example, of course, moves beyond merely defining a single POI
> structure and more into the realms of using many different POI to
> create a composite scene of independent elements relating to
> each-other - which might be outside the scope for now.
> So while there is no distinction between a real time use case and a
> non-real time in terms of the description of the data itself, when it
> comes to relating data together we might run into more issues.
> -Thomas
> On 11 December 2010 09:29, Christine Perey<cperey@perey.com>  wrote:
>> Hi Thomas,
>> I share your general position (stated in the last paragraph of your message
>> below).
>> I believe it can be paraphrased as follows: there is (in principle) be no
>> distinction in the data format used in a "real time" use case and one which
>> is not real time.
>> In fact, real time and non real time can (should) use precisely the same
>> data format and should (must) be totally independent of the architecture of
>> the application (e.g., data format identical when data is all local, partly
>> local data, all remote).
>> This means the same experience for the user if the bandwidth is unlimited
>> and the protocol is lightweight as the user experience if the data is all
>> local.
>> Does anyone believe this is a false assumption to make? What issues does it
>> raise?
>> If the above is generally considered a "fair assumption", the logical
>> extension of this is that there is no need to distinguish between a real
>> time use case and a non-real time use case.
>> Further on the topic of use cases.
>> I am unclear if the use cases need to be as specific as you describe or if
>> they can be more general.
>> In Seoul the participants of the International AR Standards meeting
>> described three AR use case (they are actually categories of use cases).
>> They have been described several times in conf calls, are depicted visually
>> in an output of the International AR Standards meeting and can be summarized
>> for completeness and quick reference as follows:
>> A. Guide: a system which leads the user through a process involving the real
>> world
>> B. Create: a system with which the user attaches/contributes a digital
>> "object" to or in the real world
>> C. Play: a system which supports bi-directional interaction between two or
>> more users in and with the real world
>> I will now connect the dots (as I see them) between the above use cases and
>> those you suggest below.
>> 1. tracking of friends or exploration (tourism applications)
>> for me, these are all specific conditions of the Guide use case.
>> 2. using AR to obtain information about a moving object which the user can
>> then use to make a decision
>> for me this is also a Guide use case which includes all the "what's around
>> me?" use cases
>> 3. tracking celestial bodies
>> another example of "what's around me?"
>> 4. game in/with the real world
>> possibly a subcase of Play use case
>> I think in order to move discussion forward on the topic of use cases, we
>> must understand what (precisely) needs to be "known" or included about the
>> complete use case to inform the definition of a suitably flexible and broad
>> data format.
>> Christine
>> Spime Wrangler
>> cperey@perey.com
>> mobile +41 79 436 6869
>> VoIP +1 (617) 848-8159
>> Skype Christine_Perey
>> On 12/10/10 2:57 AM, Thomas Wrobel wrote:
>> Seeing as the topic of real-time use case's came up recently, I
>> thought Id suggest a few rough ones for discussion or refinement;
>> 1. Tracking your friends locations when going to an outdoor event, or
>> exploring a city while on Holiday. I picture a simple "arrows from the
>> sky" depiction in the view, with each arrow being updated
>> independently above your friends every few seconds. The arrows should
>> only be visible to the friends/family members that have permission to
>> see the stream.
>> Additionally, fully public, possibly not-realtime elements should be
>> scene at the same time, such as a city map overlaid in the sky.
>> 2. Public transport tracking system. Holding your viewing client to
>> bus/train stops gives you eta's of things arriving and notices of
>> delays etc. Updated as new information comes in.
>> 3. Astronomy overlay, which shows the paths and position of heavenly
>> bodies as they pass though the sky. This angular position of these
>> objects in the sky would naturally have to change based on the time of
>> day. Nasa or Esa might also supply a update stream of their satellite
>> positions or other less predictable craft.
>> 4. A Pokemon-esq game played in a local park. Players see their
>> creatures battling around them, the creatures responding to commands
>> given.
>>   While the game rules are dealt with by a dedicated server, the data
>> is published out in a standard format, so bystanders can watch easily
>> with generic AR browser software.
>> My own view;
>> I personally feel the realtime, as well as social, is a massive area
>> for AR and should be carefully considered to ensure as flexible
>> a system as possible. However, I think for most circumstances,
>> realtime use affects more the protocol of data transmission then the
>> content itself. That is, the same format of key/value pairs
>> positioning stuff statically on a http based webserver, could also be
>> used to reposition stuff dynamically every few seconds over, say, a
>> xmpp based stream.(which also allows for  selective viewing, such as
>> in usecase1 above)
>> As long as the format stays neutral to the transmission method (ie,
>> not one strictly relaying on a webpage structure), and the required
>> POI format is lightweight enough, I -think- realtime use should be a
>> "free" possibility without extra effort.
>> -Thomas wrobel
>> ~~~~~~
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>> www.rateoholic.co.uk
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Received on Monday, 13 December 2010 19:14:41 UTC

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