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