Wireless Application Protocol (WAP)

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Wireless Application Protocol (WAP)

• Network Computing Lab
• ??? (meruru98_at_nate.com)

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Why Choose WAP

• Wireless handheld devices
• Restricted user interface (small displays and
  keypads)
• Less powerful CPU
• Reduced memory capacity
• Wireless Network
• Limited bandwidth
• Longer latency
• Lower degree of reliability

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The WAP Model
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The WAP Model
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WAP Gateway

• The WAP Gateway utilizes Web proxy technology to
  provide efficient wireless access to the Internet
• Implementation of WAP protocol stack layers
• Access Control
• Protocol conversion WSP lt-gt HTTP
• Domain Name resolution
• HTML to WML conversion
• Encording of WML content
• WMLScript compilation
• Security
• Provide caching for frequently accessed content

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WAP Protocol Stack
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WAP Protocols

• WDP (Wireless Datagram Protocol)
• End-To-End ??? ?? port ????? ??
• ???? UDP? ?? ?? ??? ??
• WTLS (Wireless Transport Layer Security)
• ???? TLS (Transport Layer Security)? ???? ??? ??
  ????
• ??(Authentication), ????(Non-Repudiation),
  ???(Constraint), ???(Security) ?? ?? ???? ??
• WTP (Wireless Transaction Protocol)
• ???? ??? ??? ?? ??? ??
• ??? ? ???? ?? ??? ???? ????? ?? ??? ??? ??

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WAP Protocols

• WSP (Wireless Session Protocol)
• HTTP/1.1? ???? ??? ??
• ??? ??? ??? ????, ?? ??? ?? suspend/resume ??? ??
• ???? ??? ?? ??? ???? ?
• WAE(Wireless Application Environment)
• ???, ??? ??? ???? ?? ?? ??? ?? ??? ??
• WML(Wireless Markup Language), WMLScript ?? ????
  ?? ???? ??? ? ?? ??? ????? ??? ? ??? ?

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WAP 1.2 2.0
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WAP UAProf and Caching

• WAP proxy may provide a variety of functions
• Protocol Gateway
• The protocol gateway translates requests from a
  wireless protocol stack to the WWW protocols
• The gateway also performs DNS lookups of the
  servers named by the client in the request URLs
• Content Encoders and Decoders
• The content encoders can be used to translate WAP
  content into a compact format that allows for
  better utilisation of the underlying link due to
  its reduced size
• User Agent Profile Management
• User agent profiles describing client
  capabilities and personal preferences UAProf
  are composed and presented to the applications
• Caching Proxy
• A caching proxy can improve perceived performance
  and network utilisation by maintaining a cache of
  frequently accessed resources

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Wireless Bearers for WAP

• The WAP protocol stack is built on top of
  wireless bearer services
• IP-based bearer
• GPRS
• UDP
• Non-IP-based bearer
• GSM SMS
• GSM USSD
• ReFlex
• IS-637SMS

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WAP SDK Simulator
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Mobile Station Application Execution Environment

• ??? ?? ???? ????
• ??? ??? ???? MS?? ???? ????? ??
• MExE classmark 1
• WAP environment
• MExE classmark 2
• Personal Java environment
• Future classmark
• Java-packages
• APIs
• ????
• On-line (de)compression? ?? video-I/O
• ??? ?? ??