Wireless Application Protocol Intro Continued Web TP Meeting
Wireless Application Protocol Intro (Continued) Web. TP Meeting H. Wilson So 28 Feb, 2000.
Outline z. Recap: What is Wireless Application Protocol? Architecture Overview z. Wireless Session Protocol z. Wireless Application Environment architecture (WML & WML-Script)
Recap … from last week
What is WAP? z"WAP specifies an application framework and network protocols for wireless devices such as mobile telephones, pagers, and personal digital assistants (PDAs). " z. WAP defines its own set of protocols but models after existing web protocols.
WAP vs. IP world z GSM, CDMA, IS-136 z WDP (datagram) z WTLS (security) z WTP (transaction) z WSP (session) z WML (markup) z WML Script (scripting) z IP z UDP z TLS (from SSL) z no counterpart z HTTP z HTML z Java. Script Rationale: reuse as much as possible from IP world, but optimize for the wireless world (i. e. compression, adapt to high-loss rate. )
WAP Protocol Architecture
Protocol Features
Part I Wireless Session Protocol
Wiress Session Protocol z. Currently defined WSP services include only browsing services WSP/B z. WSP/B is a binary equivalent of HTTP/1. 1
WSP Features Highlight z. Supports both connection-oriented and connectionless modes z. Pull: Support all HTTP/1. 1 request methods (GET, PUT, POST, etc. ) (confirmed and non-confirmed) z. Push: Server push (confirmed, nonconfirmed) z. Suspend/Resume sessions independent of transport sessions
Session Establishment / Termination
Session Establishment (over WAP Class 2)
Transaction Example
Method Invocation (over WTP Class 2)
Session Suspend/Resume
Suspend (over WTP Class 0)
Connectionless Session Service z. Provides unconfirmed (no ack or retx) facilities for: Method Invocation (GET, POST) and Push
Part II Wireless Application Environment (WAE)
What is WAE? z. Specifies an application framework for wireless devices such as mobile telephones, pagers, and PDAs. z. Defines a model suitable for buliding interactive applications that function well in narrow-band environment with medium to high latencies.
WAE Model
Components of WAE z. User Agents: in-device software that retrieves and displays content to the user. Understands WML and WML-Script z. Gateways: Conversion between HTTP & WSP and/or HTML & WML z. Various WAE specific formats: WML, WMLScript, WBMP(bitmap)
Sample WML Page z <WML> <CARD> Choose <I>all</I> you like: <SELECT KEY=“X” …. . > <OPTION VALUE=“D”>Dog</OPTION> <OPTION VALUE=“C”>Cat</OPTION> <OPTION VALUE=“H”>Horse</OPTION> </SELECT> </CARD> </WML>
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