Re: TV Namespaces a response to "mike"

From: Michael A. Dolan (miked@tbt.com)
Date: Tue, Aug 31 1999


Message-Id: <3.0.5.32.19990831171440.00974e40@cts.com>
Date: Tue, 31 Aug 1999 17:14:40 -0700
To: www-tv@w3.org (WWW TV List)
From: "Michael A. Dolan" <miked@tbt.com>
Subject: Re: TV Namespaces a response to  "mike"

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Allen-

Thanks for the response.  Comments below.  Just a suggestion - while 
I am not prepared yet personally to discuss requirements, perhaps you 

could re-post your proposal separately from this thread for those 
that might wish to?

	Mike

At 01:37 PM 8/31/99 -0400, allen mornington_west wrote:
>
>One of the earlier terms to be defined is "channel" and from its use 

in
>this document it seems that there is confusion between the use of 
the term:
>         "channel"      implying the RF carrier, or signal bearer 
mechanism
>by which a service is delivered
>and:
>        "channel" implying the commercial identity of the service 
which is
>borne.

It was not intended to be either of the above, and nothing was meant 
to be implied.  It is intended to be just the Program Stream as 
stated.  And, it is specifically *not* RF emissions, carriers, or 
commercial entities.  I would pikc a term like "Station" for this.  
Do you think this entity should be defined?

>For so much of the analog (TV) service world we have been used to 
these
>terms being the same. For a digital world we need to separate these 
senses
>- hard though this may be. One approach would be:
>        "channel"       A reference to the RF or modulated signal  
bearer
>mechanism by which a service is delivered.

This definition is inconsistent with ATSC terminology and thus 
undesirable from my perspective.  I tried carefully in these 
definitions to not conflict with any existing definitions in MPEG, 
DVB or ATSC.  They are thus not perfect for any one of these spaces, 
but they also are not in conflict.

I did think awhile about whether to call it "channel" or "service".  
I went with "channel", since there was no conflicting DVB definition 
(that I am aware of), it is more commonly understood; and thus more 
likely to be used in practice on this list by everyone.

>and:
>        "service"       A composition of signals describing audio, 
data or
>video media components (or essences)

As I noted in my definitions, this is, in fact, the DVB term for the 
ATSC channel.  As far as I can tell, your definition for "service" is 
identical to my definition of "channel" (a Program Stream).  Am I 
missing something about how your definition is different, or are you 
simply suggesting the term be "service" instead of "channel"?

>Network operators may be responsible for the operation of one or 
more
>channels and, in general, there will be one or more - often licensed 

- - -
>service providers providing programs. A program would  be thus one 
or more
>time sequential events would have been scheduled to have been 
delivered
>within a service using the channel.

You introduced several new terms above:

	network operator
	service provider
	events

So, I'm not sure everyone understands what you said (and with the new 
definition of channel, I'm not sure I do either).  Can you please 
offer definitions for these terms if you think we need them?

Regards,
	Mike

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------------------------------------------------------
Michael A. Dolan, Representing DIRECTV,  (619)445-9070   
PO Box 1673 Alpine, CA 91903        FAX: (619)445-6122