24-02-2011, 12:27 PM
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WIRELESS APPLICATION PROTOCOL
INTRODUCTION:
Mobile phones have become very popular . They offer ultimate convenience and are very useful devices for people to stay in touch. The main draw back of web based application is that the user has to stay close to the pc to use the facility. WAP has given a new dimension to web applications by doing away with the restrictions posed by pc. The growing awareness of wireless web applications aims to deliver in for that can be accessed “anywhere, anytime” using mobile.
What is WAP all about :-
The wireless Application Protocol is the de-facto world standard for the presentation and delivery of wireless information and telephony services on mobile phones and other wireless terminals.
When we use a browser to access the Internet, we have to type in an address and a web page, then a well laid-out text appears on the screen. Similarly, on the WAP enabled mobile phone, we will connect to the Internet by keying in an address, and with the help of WAP you will be able to access the web page you want.
Connecting to the Internet usually requires to dial up to an Internet Service Providers, WAP phones communicate with telephone companies that provide the cellular connection.
Inorder to guide the development of there exciting new applications the leaders of wireless telecommunication industry formed the WAP forum. The WAP forum,, which has over 200 member companies has published a global wireless protocol specification for all wireless networks spread across globe.
Challenges faced by WAP:-
Challenges provides insight into how the WAP architecture was developed and help in making sense of upcoming developments in this field. Here are some challenges faced by WAP.
1. A different market:-
Bringing computing power to a wireless handset opens an extensive new market for information access.
Ease of use:-
Mobile devices using WAP will be used by people who potentially have no desktop computing experience. Subscribers wont be focused on their handset the way that when they are sitting in front of desktop computer.
Expected service level:-
Subscribes expect wireless data access to perform like the rest of handset. The service should be instantly available, easy to use.
Short, essential tasks:
Subscriber will have small, specific tasks and need to be accomplished quickly. Receiving timely traffic alerts on the handset will be essential.
2. The device is different:-
Less powerful CPUs
Less memory
Small displays
Different input devices
Restricted power consumption
Because of these limitations, the user interface of wireless handset is fundamentally different that of desktop computer.
For example the screen size of the monitor on the desktop computer is usually 14inches to 17inches whereas the screen size of wireless device is 5inches to 6 inches.
PCs work on electricity supply whereas handled device work on batteries, which have limited capacity.
The challenges should be kept in mind when developing applications using WAP.
WAP features:
Languages:
WML has full support for user input to enable interactivity within the WAP application. WML is based on XML and is user-interface independent. The features of WML are very similar to HTML. However, bear in mind that WML is primarily for mobile devices. This Script has been optimized for use with in handheld wireless device. It makes minimal demand on memory and gives developer the flexibility to carry out client side validation.
Operating system:
WAP can be built on any operating system including palmOS, FLEXOS, OS/9, JAVAOS etc. It provides service interoperability even between different device families.
Networks that support WAP:
WAP can be used very easily on almost any wireless format. Currently WAP is being used by both GSM, CDMA and TDMA cellular phone networks. Most people talk about WAP as a GSM standard, due to the high usage of WAP by the GSM network.
We can also use pictures:
We can use pictures, but black and white only. Most of the mobile phones have a green background. Restriction is firstly there are very few mobile phones that have color displays. The main reason is speed. The data speed of the mobile phone is quite slow compared to a domestic modem. So pictures take a while to download. Images of maps can also be displayed on WAP enabled phones. The maps come from WWW.webraska.com.
WAP Models:
The main objectives is that understanding how WAP works.
WAP programming model:
WAP programming model is similar to World Wide Web programming model. WAP programming model is shown below.
WAP model consists of three entities
1. Client
2. Gateway
3. Server.
1.Client:-
This is micro browser that resides on the mobile device.
2.Gateway:-
This entity takes care of translation between WAP & WWW.
3.Server:-
This entity is the standard WWW server that contains static &dynamic content.
WAP defines a set of standard components that enable communication between mobile terminals & network servers they are.
Standard naming model:
WWW standard URLs are used to load WAP pages in the micro browser. If we need to access WAP page, then the naming convention show should be identical to existing web page.
For e.g.: A typical web address is http://Yahooindex.html
To access WAP page from web server we have to type http://Yahooindex.wml
Standard content formats:
WAP content formats are based on WWW technology .
Standard communication protocol:
WAP communication protocol enables the communication of browser request from the mobile terminal to network web server. The WAP proxy comprises of the functionality called “Protocol Gateway”. This acts mainly as a translation service that bridges the gap between WAP & WWW.
Content encoders & Decoders:
The content encoders translate WAP content into compact encoded formates to reduce the size of data over the network.
WAP Network:
The user initiates a connection to a WAP page using wireless device.
The request goes to a WAP proxy that translates the WAP requests to WWW request, allowing the WAP client to submit requests to a web server. The proxy also encodes the responses from the web server into compact binary format understood by the client.
If the web server provides WAP content the WAP proxy retrieves it directly from the web server. If it is WWW content then a filter is used to translate the WWW content to WAP content, i.e. HTML to WML.
The WTA server is an example of an origin or gateway server that responds to requests from WAP client directly. This include features like monitoring billing information, value added services registration etc. that are provided to the user based on his of her account with the network provider.
WAP Architecture:
Wireless Application Environment:
WAE is a general -purpose application environment based on a combination of World Wide Web and mobile telephony technology. This provides an open environment to allow development of application over the mobile communication infrastructure supporting WAP.
Wireless Session Protocol:
The WSP provides the application layer of WAP with connection oriented or connectionless session service operates above the WTP layer and connection less service operates above a secure of a non-secure datagram service.
Wireless Transaction Protocol:
The WTP runs on top of a datagram service and provides a lightweight transaction oriented protocol that is suitable for implementation in “thin” clients such as cellular handsets. WTP operates secure or non-secure wireless datagram transport service efficiently.
Wireless Transport Layer Protocol:
WTLP is a security protocol based upon Industry Standard TRANSPORT layer security which is used widely for secure transactions over the Internet.
Wireless Datagram Protocol:
WDP is the transport layer of the WAP protocol stack. The WDP layer operates above the capable bearer services provided by underlying cellular communication network. It provides consistent secure and non-secure services to clients irrespective of type of bearer used to send data units.
WIRELESS APPLICATION PROTOCOL
INTRODUCTION:
Mobile phones have become very popular . They offer ultimate convenience and are very useful devices for people to stay in touch. The main draw back of web based application is that the user has to stay close to the pc to use the facility. WAP has given a new dimension to web applications by doing away with the restrictions posed by pc. The growing awareness of wireless web applications aims to deliver in for that can be accessed “anywhere, anytime” using mobile.
What is WAP all about :-
The wireless Application Protocol is the de-facto world standard for the presentation and delivery of wireless information and telephony services on mobile phones and other wireless terminals.
When we use a browser to access the Internet, we have to type in an address and a web page, then a well laid-out text appears on the screen. Similarly, on the WAP enabled mobile phone, we will connect to the Internet by keying in an address, and with the help of WAP you will be able to access the web page you want.
Connecting to the Internet usually requires to dial up to an Internet Service Providers, WAP phones communicate with telephone companies that provide the cellular connection.
Inorder to guide the development of there exciting new applications the leaders of wireless telecommunication industry formed the WAP forum. The WAP forum,, which has over 200 member companies has published a global wireless protocol specification for all wireless networks spread across globe.
Challenges faced by WAP:-
Challenges provides insight into how the WAP architecture was developed and help in making sense of upcoming developments in this field. Here are some challenges faced by WAP.
1. A different market:-
Bringing computing power to a wireless handset opens an extensive new market for information access.
Ease of use:-
Mobile devices using WAP will be used by people who potentially have no desktop computing experience. Subscribers wont be focused on their handset the way that when they are sitting in front of desktop computer.
Expected service level:-
Subscribes expect wireless data access to perform like the rest of handset. The service should be instantly available, easy to use.
Short, essential tasks:
Subscriber will have small, specific tasks and need to be accomplished quickly. Receiving timely traffic alerts on the handset will be essential.
2. The device is different:-
Less powerful CPUs
Less memory
Small displays
Different input devices
Restricted power consumption
Because of these limitations, the user interface of wireless handset is fundamentally different that of desktop computer.
For example the screen size of the monitor on the desktop computer is usually 14inches to 17inches whereas the screen size of wireless device is 5inches to 6 inches.
PCs work on electricity supply whereas handled device work on batteries, which have limited capacity.
The challenges should be kept in mind when developing applications using WAP.
WAP features:
Languages:
WML has full support for user input to enable interactivity within the WAP application. WML is based on XML and is user-interface independent. The features of WML are very similar to HTML. However, bear in mind that WML is primarily for mobile devices. This Script has been optimized for use with in handheld wireless device. It makes minimal demand on memory and gives developer the flexibility to carry out client side validation.
Operating system:
WAP can be built on any operating system including palmOS, FLEXOS, OS/9, JAVAOS etc. It provides service interoperability even between different device families.
Networks that support WAP:
WAP can be used very easily on almost any wireless format. Currently WAP is being used by both GSM, CDMA and TDMA cellular phone networks. Most people talk about WAP as a GSM standard, due to the high usage of WAP by the GSM network.
We can also use pictures:
We can use pictures, but black and white only. Most of the mobile phones have a green background. Restriction is firstly there are very few mobile phones that have color displays. The main reason is speed. The data speed of the mobile phone is quite slow compared to a domestic modem. So pictures take a while to download. Images of maps can also be displayed on WAP enabled phones. The maps come from WWW.webraska.com.
WAP Models:
The main objectives is that understanding how WAP works.
WAP programming model:
WAP programming model is similar to World Wide Web programming model. WAP programming model is shown below.
WAP model consists of three entities
1. Client
2. Gateway
3. Server.
1.Client:-
This is micro browser that resides on the mobile device.
2.Gateway:-
This entity takes care of translation between WAP & WWW.
3.Server:-
This entity is the standard WWW server that contains static &dynamic content.
WAP defines a set of standard components that enable communication between mobile terminals & network servers they are.
Standard naming model:
WWW standard URLs are used to load WAP pages in the micro browser. If we need to access WAP page, then the naming convention show should be identical to existing web page.
For e.g.: A typical web address is http://Yahooindex.html
To access WAP page from web server we have to type http://Yahooindex.wml
Standard content formats:
WAP content formats are based on WWW technology .
Standard communication protocol:
WAP communication protocol enables the communication of browser request from the mobile terminal to network web server. The WAP proxy comprises of the functionality called “Protocol Gateway”. This acts mainly as a translation service that bridges the gap between WAP & WWW.
Content encoders & Decoders:
The content encoders translate WAP content into compact encoded formates to reduce the size of data over the network.
WAP Network:
The user initiates a connection to a WAP page using wireless device.
The request goes to a WAP proxy that translates the WAP requests to WWW request, allowing the WAP client to submit requests to a web server. The proxy also encodes the responses from the web server into compact binary format understood by the client.
If the web server provides WAP content the WAP proxy retrieves it directly from the web server. If it is WWW content then a filter is used to translate the WWW content to WAP content, i.e. HTML to WML.
The WTA server is an example of an origin or gateway server that responds to requests from WAP client directly. This include features like monitoring billing information, value added services registration etc. that are provided to the user based on his of her account with the network provider.
WAP Architecture:
Wireless Application Environment:
WAE is a general -purpose application environment based on a combination of World Wide Web and mobile telephony technology. This provides an open environment to allow development of application over the mobile communication infrastructure supporting WAP.
Wireless Session Protocol:
The WSP provides the application layer of WAP with connection oriented or connectionless session service operates above the WTP layer and connection less service operates above a secure of a non-secure datagram service.
Wireless Transaction Protocol:
The WTP runs on top of a datagram service and provides a lightweight transaction oriented protocol that is suitable for implementation in “thin” clients such as cellular handsets. WTP operates secure or non-secure wireless datagram transport service efficiently.
Wireless Transport Layer Protocol:
WTLP is a security protocol based upon Industry Standard TRANSPORT layer security which is used widely for secure transactions over the Internet.
Wireless Datagram Protocol:
WDP is the transport layer of the WAP protocol stack. The WDP layer operates above the capable bearer services provided by underlying cellular communication network. It provides consistent secure and non-secure services to clients irrespective of type of bearer used to send data units.
