Presentation on WAP …Keerti Sharma August 2002 Agenda… What is WAP ? Limitations of Internet for...
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Transcript of Presentation on WAP …Keerti Sharma August 2002 Agenda… What is WAP ? Limitations of Internet for...
Presentation on WAP
…Keerti SharmaAugust 2002
August 2002
Agenda…
What is WAP ?Limitations of Internet for wireless applicationsWAP Architecture / protocol stackWAP Components / WMLWAP brings Internet to hand-held devicesConclusion
August 2002
What is WAP ?
WAP – The Wireless Application Protocol – Makes it possible to access the Internet via wireless
devices such as mobile phones, PDAs etc.
– Set of rules governing transmission/reception of data by wireless devices (e.g. mobile phones)
August 2002
Limitations of Internet for Wireless Applications
Traditional Internet applications cannot run on mobile devices because of the following limitations:– Low bandwidth network– High Latency network– Limited connection stability– Small display size – Limited input facility– Limited memory– Limited processing power
August 2002
Limitations of Internet (contd)…
Low bandwidth– Size of an HTML page, including graphics … 20 KB– Download time (56Kbps modem) … 3 s– Bandwidth of wireless network …
9.6Kbps– Download time for data on one page … 17 s
High latency– At the expiry of retransmission timer value, the TCP layer resends the
packet of data– An average latency in a wireless network is around ½ s but can be as high
as 10s – This can cause a lot of retransmission causing severe congestion
August 2002
Limitations of Internet (contd)…
Limited connection stabilitySmall display sizeLimited input facilityLimited memoryLimited processing power
August 2002
WAP Architecture/Protocol Stack
August 2002
WAP Architecture (contd)…
.
Web Server
Content
CGIScripts
etc.
WM
L D
ecks
wit
h W
ML
-Scr
ipt
WAP Gateway
WML Encoder
WMLScriptCompiler
Protocol Adapters
Client
WML
WML-Script
WTAI
Etc.
HTTPWSP/WTP
August 2002
WAP Architecture (contd)…
.
WAP Application Server
Content
ApplicationLogic
WM
L D
ecks
wit
h W
ML
-Scr
ipt
WML Encoder
WMLScriptCompiler
Protocol Adapters
Client
WML
WML-Script
WTAI
Etc.
WSP/WTP
August 2002
WAP Architecture (contd)…WAE - holds the tools that wireless Internet content developers use. WSP - determines whether a session between the device and the network will be connection-oriented or connectionless. WTP - acts like a traffic cop, keeping the data flowing in a logical and smooth manner. It also determines how to classify each transaction request:
– Reliable two way (WTP/C)– Reliable one way (WTP/T) – Unreliable one way (WTP/D)
WTLS - provides many of the same security features found in the Transport Layer Security (TLS) part of TCP/IP. WDP - makes it easy to adapt the transport layer to a variety of bearers because all that needs to change is the information maintained at this level.
August 2002
WAP Architecture (contd)…
.
August 2002
WAP Architecture (contd)…
In a real WAP solution, the main components include:• WAP Device• Bearer• WAP Gateway• Content• Content Server
August 2002
WAP Components (contd)…
WAP Gateway– Encoder: converts WML to binarized WML– Adaptor: provides additional information through
HTTP header• Translate HTTP requests to WSP.• Convert between SSL and WTLS• Convert transport protocols (TCP and WDP)
August 2002
WAP Components (contd)…
WML (Wireless Markup Language)– An XML-based markup language that describes how WAP content is
presented on a wireless terminal
Differs from HTML in the following – WML was specifically designed for wireless terminals with a target screen that
is only a few lines long and about an inch wide.– WML is case sensitive, and all tags and attributes should be in lowercase.– Unlike HTML, WML is unforgiving of incorrectly nested tags.– WML doesn't assume that a keyboard or a mouse is available for user input.
Based on these differences, WML provides a smaller, telephony-aware set of tags that make it more appropriate than HTML for handheld wireless terminals.
August 2002
WAP Components (contd)…
WML Contd…– Card metaphor
• User interactions are split into cards• Navigation occurs between cards
– Explicit inter-card navigation model• Hyperlinks• History
– State management and variables• Reduce network traffic• Results in better caching
August 2002
Example of WML …
.Card
InputElements
Navigation
Variables
<WML> <CARD> <DO TYPE=“ACCEPT”> <GO URL=“#eCard”/> </DO Welcome! </CARD> <CARD NAME=“eCard”> <DO TYPE=“ACCEPT”> <GO URL=“/submit?N=$(N)&S=$(S)”/> </DO> Enter name: <INPUT KEY=“N”/> Choose speed: <SELECT KEY=“S”> <OPTION VALUE=“0”>Fast</OPTION> <OPTION VALUE=“1”>Slow</OPTION> <SELECT> </CARD></WML>
August 2002
A Deck of Cards …
.<WML> <CARD> <DO TYPE="ACCEPT" LABEL="Next"> <GO URL="#card2"/> </DO> Acme Inc.<BR/>Directory </CARD>
<CARD NAME="card2"> <DO TYPE="ACCEPT"> <GO URL="?send=$type"/> </DO> Services <SELECT KEY="type"> <OPTION VALUE="em">Email</OPTION> <OPTION VALUE="ph">Phone</OPTION> <OPTION VALUE="fx">Fax</OPTION> </SELECT> </CARD></WML>
Acme Inc.Directory_____________Next
Services1>Email2 Phone____________OK
August 2002
WAP brings Internet to Hand-held Devices
WAP handles limited bandwidth– Minimizes traffic over wireless interface– WSP layer, too, is binary encoded– WTP is not only designed to minimize amount of data but also number of
transactions
WAP handles high latency– WAE uses scripting to avoid round trip delays, e.g. by validating user input locally– WTAI environment introduces a repository to hold services that should be started
in response to an event in mobile network, e.g. incoming call.
August 2002
WAP brings (contd)…
WAP handles less stable connections – The sessions supported by WSP are assumed to be long-lived.– WTP layer has been kept very simple compared to TCP– WTP supports selective retransmission of data
WAP handles small displays – WML structures its documents in ‘Decks & Cards’– When an application is executed, user navigates through a series of cards
August 2002
WAP brings (contd)…
WAP handles limited input facilities– The WML elements can be easily be implemented without much input required from
the key-board– Deck & Cards model requires minimal navigation between pages– Soft buttons or user-definable keys are also supported by WML
WAP handles limited memory and CPU – Defining a light weight protocol stack– Limited functionality provided by WML & WMLScript– Binary encoding of WML & WMLScript
August 2002
Conclusion
WAP provides a “microbrowser” optimized for wireless devices – Requires minimal RAM, ROM, Display, CPU and keys
WAP Offers Bearer Independence – Allows Applications developed once to work across all networks – Protects the Carrier’s investment in wireless data as networks evolve– Enables Mobile Device Manufacturers to use common code across products
WAP Offers Device Independence – Allows applications developed once to work across devices from small
handsets to powerful PDAs– Promotes consistent user experience across all of a carrier’s handset offerings– Encourages a wealth of applications for handset manufacturers
August 2002
Some WAP applications
Location-based services– Real-time traffic reporting– Event/restaurant recommendation– Highly customized ads– Instant messaging-type “buddy” location
Enterprise solutions – Email access– Database access– A “global intranet”– Information updates “pushed” to WAP
devices
Financial services– Banking– Bill-paying– Stock trading– Funds transfers
Travel services– Schedules and rescheduling– Reservations
August 2002
Some known WAP Services
123Jump (http://www.123jump.com) A selection of stock data & news, all via WAP
Ajaxo (http://www.ajaxo.com) A WAP service for wireless stock trading from any WAP enabled device
2PL WorldWide Hotel Guide (http://wap.2pl.com) A hotel guide, accessible in multiple languages via WAP enabled device
Traffic Maps (http://www.webraska.com) A French service that monitors and shows latest traffic news via maps
August 2002
WAP demo
http://www.w3schools.com/wap/wap_demo.asp
August 2002
Next presentation will cover …
WAP 2.0Integrating JAVA with WAPPush Technology in WAPUsing WAP with Bluetooth
August 2002
References 1.
http://www.wapforum.orghttp://www.mobileinfo.com/WAP/components.htm http://wap.sonyericsson.com/ http://www.nokia.com/phones/9110/app.html http://www.iec.org/online/tutorials/wap/ http://www.wapaka.com/wapaka/default.asp http://www.ericsson.com/about/publications/review/2001_04/
files/2001043.pdfhttp://www.btob.barnesandnoble.com/offers/wapgap.asp?btob=Yhttp://www.w3schools.com/wap/wap_pages.asp
August 2002
References 2.
Professional WAPWAP – A Beginner’s Guide by Dale Bulbrook
Wireless Crash Course by Bedell
Cracking the Code – WAP, Bluetooth & 3G ProgrammingWAP Integration by Vujosevic & Laberge
WAP 2.0 Development by Tull