protocols for the w eb and the mobile Internet 1 November 2005 - - PowerPoint PPT Presentation

1 November 2005

protocols for the w eb and the mobile Internet

1 November 2005

agenda

HTTP

History Evolution

W@P

History Architecture WAP in the real world

1 November 2005

http history

1992 : HTTP/0.9 1996 : HTTP/1.0 informational RFC 1945 2001 : HTTP/1.1 formal standard

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http overview

request-response type of protocol stateless protocol independent of data representation

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http evolution

HTTP/0.9

• nly GET method defined for request messages

in the reply only HTML content is transmitted

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http evolution

HTTP/1.0 (1/2)

HTTP Request/Response

new message format introduced: structured multiline

message including headers

appending the HTTP version in the request message

MIME type included

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http evolution

HTTP/1.0 (2/2)

new methods defined: HEAD, POST, PUT, DELETE, LINK, UPLINK basic user authentication

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http evolution

Request = Request-Line *(( general-header | request-header | entity-header ) CRLF) CRLF [ message-body ]

Request-Line = Method SP Request-URI SP HTTP-Version CRLF Response = Status-Line *(( general-header | response-header | entity-header ) CRLF) CRLF [ message-body ] Status-Line = HTTP-Version SP Status-Code SP Reason-Phrase CRLF

HTTP/1.1 (1/2)

Request/Response message formats finalized

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http evolution

HTTP/1.1 (2/2)

Persistent connection added New request methods:PUT, OPTIONS, TRACE & CONNECT Headers: general-header, request-header, response-header and entity-header used to send information about the HTTP message

host header Range, Content Range headers

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HTTP and the Web in the future...

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w ireless application protocol

Why is it need?

The web gained enormous popularity Mobile telecommunications matured Next step: Internet anywhere anytime

The web though is designed for desktops that have access to high bandwidth and reliable network connections WAP will provide for optimization for the wireless environment and will address its limitations

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w ap: challenges

Device constrains

Less powerful CPUs Less memory Restricted power consumption Smaller displays Different input devices (e.g a phone keypad, voice input, etc.)

Network constrains

Low bandwidth High network latency Less connection stability Less predictable availability

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w ap history

1997: WAP Forum established

(Nokia, Ericsson and Motorola, Phone.com )

1998: WAP 1.0 2002: WAP 2.0

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w ap 1.0

Objectives

To bring Internet content to the wireless terminals To create a protocol specification that will work across different wireless network technologies To enable the creation of content that scales across many wireless bearer networks and wireless device types To extend existing standards wherever appropriate

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w ap 1.0 architecture

WAP 1.0 Programming model

fig.WAP 1.0 Programming Model [2]

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w ap 1.0 architecture

WAP 1.0 Protocol Stack

• fig. WAP 1.0 Components [2]

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w ap in the real w orld

Massive publicity started well before WAP was available. Marketed as the next Internet revolution First WAP services launched in 1999

(Sonera the first operator to provide wap services)

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w ap in the real w orld

Usability issues

Usability studies Difficult to configure. over-the-air configuration available Transactions(browsing) are really slow

Service is expensive

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w ap in the real w orld

”Broken promisses or wrong expectations”

The killer application never materialize Not so many WAP resources available

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w ap 2.0

Objectives

Add support for the standard Internet protocols Continues to work on the goals set by WAP 1.0

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w ap 2.0 architecture

WAP 2.0 Programming model

WAP 2.0 Programing Model [3]

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w ap 2.0 architecture

WAP 2.0 Legacy Protocol Layers

WAP 2.0 Components [3]

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w ap 2.0 architecture

WAP 2.0 Protocol layers for IP support

WAP 2.0 with support for standard Internet protocols [3]

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w ap 2.0 architecture

WAP 2.0 Components

Wireless Profiled HTTP Transport Layer Security Wireless Profiled TCP

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the competitor

i-mode

A proprietary service (owned by NTT DoCoMo) Can practically read any Web page

i-mode uses compact HTML (cHTML) which is

practically subset of HTML with some I-mode specific tags

Packets-witched

Charging based on transfer not air time.WAP initially

used circuit switching

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i-mode

“If i-mode was a superior specification or technology, then other companies would have adopted it by now. But 500-and-some companies have gotten behind the WAP standard rather than the I-mode standard. That's got to tell you something.” , article 2000 WAP or I-Mode: Which Is Better?, www.wired.com

the service is expanding globally since 2002

Available in Germany, Taiwan, The Netherlands,

Belgium, France, Italy, Greece, Australia, Israel, Russia , United Kingdom and Ireland

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The future of wap...

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references

Hypertext Transfer Protocol – HTTP/1.1 , Standard Track Wireless Application protocol White Paper At http://www.wapforum.org/what/WAP_whitepages.pdf Wireless Application Protocol WAP2.0 Technical White Paper At http://www.wapforum.org/what/WAPWhite_Paper1.pdf WAP Field Study Findings At http://www.useit.com/alertbox/20001210.html WAP: Broken Promises or Wrong Expectation? , The Internet Protocol Journal, Volume 6, Number 2, June 2003. Available at www.cisco.com

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references

The unofficial independent imode FAQ At http://www.eurotechnology.com/imode/faq.html I-mode , At www.nttdocomo.com Content Networking in the Mobile Internet, Sudhir Dixit and Tao Wu, ISBN: 0-471-46618-2