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What is WAP ?y WAP The Wireless Application

Protocoly Makes it possible to access the Internet via wireless

devices such as mobile phones, PDAs etc.

y Set of rules governing transmission/reception of databy wireless devices (e.g. mobile phones)

 August 2002

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Why WAP?y WAP is an open technology based on Internet technologiesy Allows competition - lower cost

y WAP is backed by major vendors

yNokia, Ericsson, Motorola, Microsoft, IBMyFuture proof 

y WAP Forum is open for ally WAP is not take it or leave ityOver one hundred companies have joined the WAP Forum

y WAP supports several wireless systemsyGSM, IS-136, CDMA, PDC etc.

y WAP has a layered architectureyThe same application can be used via several systems

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Limitations of Internet for

Wireless Applications

y Traditional Internet applications cannot run onmobile devices because of the following

limitations:y Low bandwidth network

y High Latency network

y Limited connection stability 

y Small display size

y Limited input facility 

y Limited memory 

y Limited processing power

 August 2002

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Limitations of Internet (contd)y Low bandwidth

y Size of an HTML page, including graphics 20 KB

y Download time (56Kbps modem) 3 s

y Bandwidth of wireless network 9.6Kbps

y Download time for data on one page 17 s

y High latency y At the expiry of  retransmission timer value, the TCP layer 

resends the packet of data

y An average latency in a wireless network is around ½ s but can beas high as 10s

y This can cause a lot of retransmission causing severe congestion

 August 2002

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WAP Programming Model

CGI,

Scripts,Etc.

C onten

t

Web Server 

C lient

 WA EUser Agent

Request(U RL)

Response(Content)

Gateway

Encoders A ndDecoders

E ncoded 

Request

E ncoded Response

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Internet

HTMLJavaScript�

HTTP

TLS - SSL

TCP/IPUDP/IP

Internet and WAP architecture

Wireless ApplicationEnvironment (WAE)

SMS USSD CSD R-Data Packet UDP PDC-P Etc...

Bearers:

Wireless Application Protocol (most imp question )

Wireless Session Layer (WSP)

Wireless Transport Layer Security (WTLS)

Wireless Datagram Protocol (WDP)

Other Services andApplications

Wireless Transaction Protocol (WTP)

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Wireless Application Environment (WAE)

� General-purpose application environment

 based on a combination of WWW and

mobile telephony technologies.

� It defines the user interface on the phone. It

contains WML and WTA (Wireless

Telephony Application).

� Primary objective ± interoperable

environment.

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Wir l ss licati E vir t

(C t .)�  WAE includes a micro-browser (Client software

designed to overcome challenges of mobile handhelddevices that enables wireless access to services suchas Internet information in combination with asuitable network ) server environment which provides

 ± WML

 ± WML script

 ± WTA 

 ± Content formats

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Wireless Session Protocol (WSP)

�The WAP session protocol (WSP) layer providesa lightweight session layer to allow efficientexchange of data between applications

.

� Application layer with a consistent interface for two session services

 ± Connection-oriented service that operatesabove the transaction layer protocol (WTP)

 ± Connectionless service that operates above asecure or non-secure datagram service (WDP)

� O ptimized for low-bandwidth bearer networkswith long latency

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Wireless Transaction Protocol (WTP)

y R uns on top of a datagram service

y The WAP transaction protocol (WTP) layer 

 provides transaction support, adding reliability to

the datagram service provided by WDP.y Light weight transaction-oriented protocol

y Three classes of transaction services

y Unreliable one-way requests

y Reliable one-way requests

y Reliable two-way request-reply transactions

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Wireless Transport Layer Security (WTLS)

Based on industry-standard Transport Layer 

Security (TLS) protocol

y O ptimized for use over narrow-band

communication channelsy Features:

y Data integrity

y Privacy

y Authentication

y Denial-of-service protection

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Wireless Datagram Protocol (WDP)

y The WAP datagram protocol (WDP) is theTransport layer that sends and receives messagesvia any available bearer network, including SMS,USSD, CSD, CDPD, IS±136 packet data, and

GPRS.

y O perates above the data capable bearer servicessupported by various network types.

y Provides a common interface to the upper layer  protocols and hence they function independent of the underlying wireless network.

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Bearers

y Differing levels of quality of service with respect to

throughput, error rate, and delays

y WAP protocols are designed to compensate for or 

tolerate these varying levels of service

y WDP specification lists the bearers that are supported

and techniques used to allow WAP protocols to run

over each bearer 

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 DISADVANTAGES of WAP 

�  Small screens: For web phones, there's an incredibly small

viewing area; palmtops are barely better.�  Speed of access: All devices have slow access.

� Li mit ed or fragment ed avai labi l ity: Wireless web access issporadic in many areas and entirely unavailable in other areas.

�  Pr i ce: Many technology limitations are being addressed byhigher-end devices and services. But the entry price for agood wireless web palmtop with decent display, keyboard,and speed is easily $700 to $900, not including monthly

access.

� Lack of user habit : It takes some patience and overcomingthe learning curve to get the hang of it -- connecting, puttingin an address, typing. Users just aren't used to the idea and

 protocol yet.

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US A GE

- Corporate Applications: Sales force automation

where sales people use their WAP enabled handsets toget instant, direct access to the latest pricing, latest

news, competitive information any time, anywhere.

- Online Services:

 Bank i ng: Users can get their current balance,

transfer funds between accounts and receive fax of a

mini-statement.

 Elect roni c Commerce: Subscribers can use their handset just like their PC to purchase products and

services over the Web.

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- Tele services

 Prepai d Servi ces: With a WAP-enabled phone, prepaid subscribers can see their current balance with

the press of a button. By pressing another button,they can also recharge their account by entering acredit card or voucher number into the handset.

- Personal Productivity

 Emai l: Using WAP users can keep track of their email right from their handset.

- Others include: 

- Interactive Chat

- Auctions

- Games

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What is iMode?

y Goal: Easily enjoy Internet services on mobilephone

y

Overlay on top of DoPa packet networky Subscriber:

y New, advanced services on mobile device

y Operator:

y  A way to attract new users and increase revenuey Users charged on per-packet basis (~0.22

cents/128byte)

y Payment collection for third-party informationproviders