Application Standards for Push Content and Streaming Media

1
Application Standards for Push Content and
Streaming Media

• Hadi Partovi
• Microsoft Corporation

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Agenda

• Justification
• Technologies of today
• Smart Pull
• True Push, Streaming Media
• CDF - Unifying Pull and Push
• Demo, Details
• Technologies of tomorrow
• Searching and Filtering
• Profiling and Personalization

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Justification

• The Web today
• Different standards for pull vs. push
• Many different push mechanisms, transports
• No interoperability in push
• The Web tomorrow
• New ways to manage content
• Even greater need for interoperability

4
Technologies of today

• Smart Pull
• True Push
• Streaming Media

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Push Smart Pull?

• Smart means automated, scheduled pull
• HTTP as the underlying transport
• Driven by data about the content
• User Interface provides push experience
• Many players in this space

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Smart PullDelivering Content for Offline User
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True Push (1 of 2)

• New transport protocols solve problems not
  addressed by HTTP today
• Multicast information to many clients efficiently
• Data change notifications
• Different physical media (e.g. airwaves)

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True Push (2 of 2)

• Diverging solutions for multicast and broadcast
  protocols
• Many of these protocols also include similar
  directives
• What content to deliver
• Schedule

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Streaming Media

• Similar to true-push multicast solutions
• Similar directives for streaming content
• What streams to play
• Timing information
• Many more problems beyond regular Web content
  (out of scope)
• Video / presentation issues

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Channel Definition Format

• Unifying Push and Pull
• Demo
• Details

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CDF - Unifying Pull and Push

• Author once for different delivery mechanisms
• Single, simple data format, procedural API
• eXtensible Markup Language (XML)
• Document Object Model
• Extensible vocabulary for common application
  directives
• Scalable

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What is a channel?

• Meta-information about content
• Automated delivery
• Offline use
• Personalization rules
• Vision supplied by many companies

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The role of CDF

• Existing vocabulary has played a unifying role in
  the marketplace
• Majority of push clients, servers, tools
• Countless content sites
• Evolved from Sitemaps (HTML-WG)
• Built on XML - (first widely publicized
  application of XML)
• CDF-based solutions for smart pull or true push

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Flexibility of Implementation

• Interoperable client, server, tool
  implementations available today
• IE4 will provide best of breed, cross platform.
• Open COM-based architecture allows multiple
  transport protocols to plug in
• Independent of content format

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CDF - Demo

• Content hierarchy
• Offline use
• Display directives

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CDF - Selected Details

• Content grouping
• Update Schedule
• Display preferences

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CDF - Content Grouping

• Hierarchical grouping
• ltCHANNELgt and ltITEMgt
• Absolute or relative URLs
• ltBASEgt just like HTML
• Cache directives
• LASTMOD attribute (avoid roundtrip)
• PRECACHE attribute (for offline use)
• LEVEL attribute (for crawling subtrees)

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CDF - Update Schedule

• Required update frequency
• INTERVALTIME
• Optional channel lifetime
• STARTDATE, ENDDATE
• Optional - control over time of update
• EARLIESTTIME, LATESTTIME

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CDF - Display Preferences

• ltLOGOgt - visual cues
• for channels or items
• ltUSAGEgt - display venue for presenting channel or
  item content
• e.g. channel-viewer
• e.g. screen-saver
• e.g. a notification pop-up
• e.g. a printer

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OSD - Open Software Description

• Philosophically aligned with CDF
• Value is in vocabulary
• XML for syntax
• DOM for procedural API
• CDF is vocabulary for content
• OSD is vocabulary for software packages
• Dependencies per platform/lang/etc

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Technologies of Tomorrow

• Searching, Filtering
• Profiling, Personalization

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Moving Forward - Searching, Filtering, Aggregating

• Client-side or Server-side
• Push vocabulary helps search content, filter
  unwanted info, aggregate desired info
• Use XML-Namespaces and XML-RDF to add annotations
• Search results themselves may be pushed
• Need language and application rules for CDF
  filtering

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Profiling and Personalization

• Again, personalize on client or on server
• Upcoming work from P3 group - profiling
• Communicating private info between client and
  server
• Pushed content should be personalized
• Client-side personalization essential for many
  true-push mechanisms
• Need common standard for CDF personalization
  directives

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CDF Futures

• CDF v1 - shipping, industry momentum
• CDF v2
• Filtering / Personalization language, rules
• Vocabulary extended (use XML Namespaces)
• Relationship to other proposals (XML for native
  types, XML-RDF for annotation, OSD for software
  push)

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Summary

• Need standards in diverging area of push
• Many future technologies at stake
• CDF is already in use by over 50 software
  vendors, over 1,000 high-profile web sites
• Clients, Servers, Tools - shipping, many impls
• Wire (or air) Protocols
• Content - grassroots momentum
• Looking forward to formalizing CDF, defining
  future versions