WAP stands for Wireless Application
Protocol. This is one of areas of interest. Do read on to
know more about this technology...
Important
Note:
The URL of my WAP Site is
http://www.praveenks.com/wap/index.wml
If you have a WAP enabled cell phone
or device, then you can check out my WAP Site by pointing your
device to the URL mentioned above.
To see the WAP version of this
website, you may use the SmartPhone Emulator provided
by Yospace. Please click on the link below to use the Emulator:
http://www.yospace.com/spedemo.html
Once you are there, you can choose any of the several phone
emulators given. However, I would recommend that you choose the Nokia 7110 Media Phone or the Yospace YoPad models.
The Opera Web
Browser is WAP enabled. If you are using it, then you can
just copy and paste the above URL into the Address Bar.
1. What is WAP?
The Wireless Application Protocol (WAP) is a global standard developed to make Internet services available for mobile
users. It provides a uniform technology platform with
consistent content formats for delivering Internet and Intranet based
information and services to digital mobile phones and other wireless
devices. Even though WAP is based on Internet technology, WAP and the
Internet live side by side. A company or a person that has an Internet
site can make the information available for mobile users by
transforming the pages into WAP pages.
2. History of WAP
In 1995, Ericsson initiated a project whose purpose was to develop a
general protocol called Intelligent Terminal Transfer Protocol (ITTP)
to enable value added services on mobile networks. During 1996 and
1997, Motorola, Nokia, and Unwired Planet (at present Phone.com)
launched similar concepts. Unwired Planet presented Handheld Device
Markup Language (HDML) and Handheld Device Transport Protocol (HDTP).
Just as Hyper Text Markup Language (HTML) is used on the WWW, HDML is
used for describing content and user interface, but it is optimised
for wireless Internet access from handheld devices with small displays
and limited input facilities. In the same manner HDTP could be
considered to be a wireless equivalent of the standard Internet Hyper
Text Transport Protocol (HTTP), i.e. a lightweight protocol to perform
client/server transactions. In March 1997, Nokia officially presented
the Smart Messaging concept especially designed for handheld GSM
devices. The communication between the mobile user and the server
containing Internet information uses Short Message Service (SMS) and a
markup language called Tagged Text Markup Language (TTML) similar to
HDML. To avoid clash among these varied technologies and to develop a
global wireless protocol specification, these four companies
co-founded the WAP Forum on June 26, 1997. Thus, WAP was born.
3. WAP Architecture
WAP is designed in a layered fashion in
order to be extensible, flexible, and scalable. The WAP-stack
basically is divided into five layers:
The WAP layered architecture enables
other services and applications to utilise the features of the WAP
stack through a set of well-defined interfaces.
3.1 WAP Application Environment (WAE)
The uppermost layer in the WAP stack, the Wireless Application
Environment (WAE) provides an environment that enables a wide range of
applications to be used on wireless devices. WAE includes a
micro-browser environment containing the following functionality:
Wireless Markup Language (WML), WMLScript, Wireless Telephony
Application (WTA, WTAI) and Content Formats.
3.2 The Other
Layers
WSP is the interface between WAE and the rest of the protocol stack.
It is a binary version of HTTP 1.1 with additions such as: capability
negotiation, header caching, long-lived sessions, session suspend and
resume etc. WTP is responsible for control of transmitted and received
messages. WTP works with three different message classes: Unreliable
"send", Reliable "send" and Reliable "send" with reliable result
message. WTLS is a security protocol based upon the industry-standard
Transport Layer Security (TLS) protocol, formerly known as Secure
Sockets Layer (SSL). It provides the following features: Data
integrity, Privacy, Authentication and Denial-of-service protection.
WDP is the base of the WAP protocol stack and it provides a consistent
interface to the upper layers of the stack. It hides the
characteristics of different bearers and provides port number
functionality.
4. What is WML?
WML stands for Wireless Markup
Language. WML is WAP’s analogy to HTML used on the WWW. WML is
based on the Extensible Markup Language (XML).
WML uses a deck/card metaphor to
specify a service. A card is typically a unit of interaction with the
user, that is, either presentation of information or request for
information from the user. A collection of cards is called a deck,
which usually constitutes a service. This approach ensures that a
suitable amount of information is displayed to the user simultaneously
since inter-page navigation can be avoided to the fullest possible
extent.
Key features of WML include:
· Variables
· Text formatting features
· Support for images
· Support for soft-buttons
· Navigation control
· Control of browser history
· Support for event handling (for e.g. telephony services)
· Different types of user interactions, e.g. selection lists and input
fields
WML can be binary encoded by the WAP Gateway/Proxy in order to save
bandwidth in the wireless domain.
5. How do we view WAP sites?
To view WAP sites, we need a WAP browser. Normal web browsers like
the one you are using right now can't be used to view WAP pages.
There are various WAP browsers available like Klondike, WinWap etc.
However, these WAP browsers have to be downloaded and installed on
your computer.
The second option is to use an Online Emulator.
These Emulators convert the WML pages into HTML pages. Thus, we are
able to see the contents of a WAP page even though we are using a
normal Web browser. What actually happens is that on entering the
URL and pressing the Go! Button, the control is transferred to a
JavaScript. The JavaScipt then calls a CGI program on the server
side. The CGI program converts the WML code into HTML code and sends
back the modified code back to the browser. Thus, what we see on the
Emulator is the HTML version of the WML page and not the actual WML
page.
To see the WAP version of this website, you may use the
SmartPhone Emulator provided by Yospace. Please click
on the link below to use the Emulator:
http://www.yospace.com/spedemo.html
Once you are there, you can choose any of the several phone
emulators given. However, I would recommend that you choose the Nokia 7110 Media Phone or the Yospace YoPad models.
