Re: looking for tv-related URI use cases/application scenarios

From: Gomer Thomas (
Date: Wed, Dec 16 1998

Message-ID: <>
Date: Wed, 16 Dec 1998 13:06:20 -0500
From: Gomer Thomas <>
To: Aninda DasGupta <>
CC: "''" <>
Subject: Re: looking for tv-related URI use cases/application scenarios


Actually, I think the kinds of specifics about carriage of URIs in VBI lines
or MPEG tables which Tim is providing are exactly the kinds of specifics
which are needed in a use case. The whole point of a use case is to
understand from a user value perspective what the real requirements are
(where the "user" may be a content producer, a broadcaster, a re-broadcaster,
a receiver manufacturer, and/or a consumer). This requires as much specifics
as possible about context.

I think you have a number of good use cases in mind yourself, but I wonder if
you can provide a little more detail, so that we can truly see what the
business/user/technology context is:

(a) Announcement on a Web site of a future TV show -- Is this the Web site of
a local broadcast affiliate directing viewers to its own broadcast? Is this
the Web site of a national or international network directing viewers to any
local broadcast of its network feed? Is this the Web site of the producer of
the TV show directing viewers to any broadcast of its show by any network or
affiliate? Specific examples would be useful. Is this a WBGH Web site? CNN
Web site? Turner news Web site? MGM Web site?
(b) Announcement within EPG data of a future TV show -- Do you mean the
announcement is in the entry in the EIT or in the ETM (in the ETT) for the
future TV show itself? If not, what assumptions are there about co-location
of the event for which the ETM contains the announcement and the event for
the future TV show? Are they in the same virtual channel? in the same
transport stream? no assumptions? Or does the announcement appear in some way
in the VCT (using some possible future descriptor designed to contain such
(c) Association/binding of "channels" -- Where did the references come from?
What was the business motivation of the source?
(d) References to a broadcast "object" from anywhere -- This sounds to me
like it is clumping together a large number of individual use cases into a
single summary case. I fear a lot of useful insight has been lost in the

This may all sound like it is nit-picking, but the point is that without such
detail one can easily interpret each of the cases in many different ways
leading to many different requirements, some much less stringent than

Aninda DasGupta wrote:

> I'd stay away from specifics of carriage of URLs in VBI lines or
> MPEG tables, etc.  But what Tim seems to suggest is that URLs are used
> to trigger "loading" of a "page" of content to enhance the video
> program.
> The other two possible uses of URLs are:
> - announcement of a future TV show.  Placing such announcements on
>     Web sites and within EPG data carried in broadcast TV content.
> - association/binding of "channels" (NTSC channels/frequencies, or MPEG
>     program within a transport stream) with references to such channels.
> - references to any broadcast "object" (data item, video program, etc.)
>     from anywhere (web pages, broadcast streams, databases...).
>     This use is truly the universal resource identification function of
>     URIs, and in many ways a generalization of all uses of URIs that
>     people have mentioned to me.
> -Aninda
> "Chambers, Tim" wrote:
> >
> > Let's start this off with basics:
> >
> > It would be a trigger encoded into the line21 of the VBI (which is must
> > carry for broadcasters) of a tv show that loads up a "jump page" of
> > enhanced tv content that supplements the television program.
> >
> > Tim
> >
> > > -----Original Message-----
> > > From: Philipp Hoschka []
> > > Sent: Tuesday, December 15, 1998 12:46 PM
> > > To:
> > > Subject: looking for tv-related URI use cases/application scenarios
> > >
> > >
> > >
> > > To better motivate the requirements, and evaluate their priorities,
> > > the URI telecon this morning decided that we're lacking application
> > > scenarios how tv-related URIs would be used
> > >
> > > So, if you have a particular idea of how tv URIs will be used,
> > > please send it to this mailing list
> > >
> > > We have an editor (Craig Finseth) who will summarrize these
> > > scenarios in a coherent document
> > >
> > > -Philipp Hoschka, W3C
> > >
> --
> Aninda DasGupta              
> Philips Electronics                    Phone:    +1 914 945 6071
> Briarcliff Manor NY 10510              Cellular: +1 914 671 7390
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Gomer Thomas
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