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w3c Mobile working group - Content transformation task force - Draft problem statement

From: Swainston, Andrew, VF UK - Technology \(TS\) <Andrew.Swainston@vodafone.com>
Date: Mon, 13 Aug 2007 18:01:40 +0100
Message-ID: <B77796343B16E047B045999EC4460F0D0663EE55@UKWMXM02>
To: <public-bpwg-ct@w3.org>

All,
 
Below is my draft of the problem statement. I would be grateful if you
could read it before our conference call tomorrow (Tuesday 14 August).

I have tried to capture all the points in Rhys Lewis' email of 20 July
(from the face-to-face meeting). I have tried to focus on the problem
and avoid any solutions.

Best regards,

Andrew

Andrew Swainston
Technical Manager
Mobile Applications & Content Services - Telecom Systems

Mobile: +44 7899 728960
Email: andrew.swainston@vodafone.com

Vodafone Limited
Registered office: Vodafone House, The Connection, Newbury RG14 2FN, UK
Registered in England No 1471587 

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----------------------
<Problem statement - start> 
 
w3c Mobile working group - Content transformation task force
 
Problem statement
=================
 
Introduction
------------
 
Many web sites provide pages that do not work well on mobile devices.
These pages are intended to be viewed only by desktop browsers. Typical
of the problems encountered when trying to access such pages with a
mobile device are: that the page layouts assume a screen larger than the
device supports; that the pages require more memory than the device
supports; that a full querty keyboard and mouse are required to use the
page; or, that the page uses content types that the device does not
support. These sites will either send such a pages to the mobile device,
which will try to display it, or send an HTTP error status code. These
sites can be referred to as mobile unaware sites.
 
Content transformation proxies, situated in the communications path
between the mobile device and the web site, are able to transform the
content of such pages to enable effective display and use on mobile
devices. Many parties, including mobile operators and search engines,
are introducing content transformation proxies to allow mobile device
users to access the bulk of sites and pages on the Internet.
 
Content transformation proxies typically work by masquerading as desktop
browsers, fetching content and then modifying it before returning it to
mobile devices. These transformations range, for example, from simple
character set corrects, through image reformatting and resizing, layout
modifications and page segmentation, to multi step JavaScript
transaction emulation. Content transformation proxies can also add
content to, or remove it from a page.
 
While this approach is very effective for mobile unaware sites, it
presents on obstacle to mobile aware sites which provide content
intended for mobile devices. The masquerading technique prevents mobile
aware sites from detecting the mobile devices that originate requests;
the sites only detect a desktop browser. Mobile aware sites may provide
mobile compatible pages or mobile compatible content like ring-tones or
Java applications. The designers of such sites may prefer any content
transformation proxies leave both the mobile devices request and the
returned content unchanged. Some sites may cater for both desktop
browsers and mobile devices. In these cases the user of a mobile device
may prefer to choose which site he or she accesses.
 
Content transformation also offers opportunities to site designers,
allowing their sites to be served to a wide range or devices while
freeing them from having to detect and keep up to date with the
capabilities of new devices.
 

The problem
-----------
 
Techniques are needed to enable content transformation proxies to be
used, so that mobile devices can access both mobile aware sites and
mobile unaware sites, providing mobile device users the maximum possible
access to the Internet.
 
Techniques need to be identified or designed to enable the following:
 
  - Identify mobile content during a request
 
  - Identify all actors in the delivery context so that they can find
out about each other
 
  - Identify the originating user agent and its capabilities to
intermediary proxies and the origin server
 
  - Identify an intermediary proxy's capabilities (including
transformation capabilities) to other intermediary proxies and the
origin server
 
  - Indicate a user's or site designer's intent to intermediary proxies
 
  - Enable user control of the experience - e.g. deciding whether they
want the desktop or mobile experience when there is a choice.
 
  - Enable site designers to provide content transformation hints to
intermediary proxies 
 
 
The impact of content transformation on security needs to be considered
and any recommendations made.
 
The implications of operations such as advert insertion and similar
changes to original content needs to be considered and any
recommendations made.
 

Constraints
-----------
 
These techniques should operate within existing technology.


<Problem statement - end>
Received on Monday, 13 August 2007 21:12:42 GMT

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