RE: webtv-ISSUE-24: Please show feasible implementation

Hello Russell,

I believe the UPnP follows the same approach I indicated.

The UPnP Device Architecture defines the fundamental framework of home networking. The UPnP forum have developed the standard UPnP device and service based on the UPnP Architecture, as you described. But, vendor may also define vendor-specific UPnP device/service as the architecture allows it. Note that the IPR policy of UPnP forum is different from that of W3C.

PS. I did not sticky on any specific underlying solution, e.g. UPnP, for this use case.

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Tatsuya Igarashi　(Tatsuya.Igarashi@jp.sony.com<mailto:Tatsuya.Igarashi@jp.sony.com>)
NS Development Dept. Technology Development Group
Sony Corporation
(Voice) +81-3-5435-3252　(Fax) +81-3-5435-3274




From: Russell Berkoff [mailto:r.berkoff@sisa.samsung.com]
Sent: Tuesday, June 14, 2011 8:51 PM
To: Igarashi, Tatsuya; public-web-and-tv@w3.org
Subject: RE: webtv-ISSUE-24: Please show feasible implementation

Hello Igarashi-san,

Thank you for your answers.

I will point out that UPnP (or the generic use-cases in ISSUE-16) does not fundamentally differ from the approach you indicate.

An application-id is similar to a serviceType in UPnP. The author of a service (serviceType) defines the methods and parameters supported by that service. In UPnP services are discovered dynamically although some commonly used devices like media servers and renderers have include pre-defined sets of services that control various aspects of device control. For example UPnP groups playback control (play, stop pause) an rendering controls (set brightness, set volume, etc) as separate services in a media renderer device.

Regards,
Russell Berkoff


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From: Igarashi, Tatsuya [mailto:Tatsuya.Igarashi@jp.sony.com]
Sent: Tue 6/14/2011 4:32 AM
To: Russell Berkoff; public-web-and-tv@w3.org
Subject: RE: webtv-ISSUE-24: Please show feasible implementation
Hello,

My comments are interleaved below;

From: public-web-and-tv-request@w3.org [mailto:public-web-and-tv-request@w3.org] On Behalf Of Russell Berkoff
Sent: Tuesday, June 14, 2011 7:17 PM
To: public-web-and-tv@w3.org
Subject: webtv-ISSUE-24: Please show feasible implementation

Hello,

I dont understand the proposed implementation for ISSUE-24.

For a sender and receiver to communicate successfully they not only need to be able to discover each other, but in addition they need to agree on the syntax and  semantics of the communication.

(Igarashi) Yes, I think so.

The use-case mentions "application-id" but provides few additional details. Is the use-case implying that all the messaging semantics are derived from this application-id? I dont see this as being a very viable ecosystem if each web-page declares its own application-id and associated semantics that an arbitrary receiver may or may not understand.

(Igarashi) The use-case assumes that all message semantics are identified by the application-id. In terms of the ecosystem, we assume an ecosystem similar to that of the open web platform. Fundamentally, such kind of basic framework provides a huge benefit of broader ecosystem because each stakeholder utilizes the framework for its own service and applications (assuming the semantics of message is disclosed). In addition, if the semantics of message is open, any other stakeholder may make the application which communicates another application provided by another stakeholder. This is similar to the case that service mash up of web APIs is popular on the web.

Even one of the end-points delivered a JS wrapper around a socket to facilitate the communications, then the methods provided by this wrapper would need to be agreed to be the UA interfacing to the application.

(Igarashi) I think we should separate the standardization of semantics of message formats from the standardization of the basic framework for the message exchange. This is reasonable because W3C cannot standardize all of semantics of web communications, though W3C should some if necessary.

Thank you.

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Tatsuya Igarashi　(Tatsuya.Igarashi@jp.sony.com<mailto:Tatsuya.Igarashi@jp.sony.com>)
NS Development Dept. Technology Development Group
Sony Corporation
(Voice) +81-3-5435-3252　(Fax) +81-3-5435-3274


Could you clearly define some feasible implementations for this  use-case?

Regards,
Russell Berkoff