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Wireless Application Protocol - WAP Where does WAP Fit in the Wireless Computing Application? Three
are three essential product components that you need to extend your host
applications and data to WAP-enabled devices. These three components are:
WAP
Micro-browser Lots of WAP browsers and emulators are available free of cost which can be used to test your WAP pages. Many of these browsers and emulators are specific to mobile devices. For example the R380s WAP emulator is intended to be used for testing WML applications developed for the WAP Browser in the Ericsson Smartphone R380s. You can find a list of downloadable WML Browsers/ Emulators at www.2thumbswap.com/downloads/index.htm.
WAP emulators can be used to see how your site will look like on specific phones. As these images show, the same thing can look different on different mobile phones. So, the problems that web developer faces with the desktop browsers (Netscape/Iexplorer) is present here also. So, make sure you test your code on different mobile phones (or simulators) WAP
Products - Microbrowser, WAP Gateway, WAP servers WAP Gateway To
connect these two mega-networks, the WAP Specification assumes there will be a
WAP Gateway. At its simplest level, this is a stack converter, which will
convert the WAP request into a Web request and the Web response into a WAP
response. WAP
Gateway is a piece of software that sits between the mobile device and the
external network like the Internet. The gateway does the job of converting
Internet content i.e. the WML pages into byte code (WMLC) which can be understood
by a WAP device. Usually located on a server of a mobile operator it handles
incoming requests from your WAP phone, takes care of the conversion required
during WTLS/SSL sessions and handles incoming requests from your WAP phone.
Although in theory, the gateway could also be made to convert the HTML page
content itself on-the-fly as well, there are some problems. HTML pages can be
full of graphics and with inline scripting. Converting these to WML may return
something that is not of any relevance to anybody. Some
of the WAP Gateway products that are now coming on to the market (such as
Nokia's WAP Server) also provide hosting capabilities themselves. In future it
could be possible to integrate your WAP Server into the mobile network to gain
information about the subscriber's location. If you host your own gateways, then it may be required to maintain some sort of connection with the mobile network. For example, in case of GSM networks you may need to have say a dial up connection with the network's SMS engine or you may need to provide dial in modems for CSD access (Circuit Switched Data, around 9.6 kbps data rate)
There
is a large list of available gateways at wapdrive.net. You can get
your WAP gateway form A WAP server is simply a combined web server and WAP gateway. WAP devices do not use SSL. Instead they use WTLS. Most existing web servers should be able to support WAP content as well. Some new MIME types need to be added to your web server to enable it support WAP content. MIME stands for Multipurpose Internet Mail Extension, and in the web context, MIME can be thought of as a piece of header information that comes down with every file sent from a web server to a browser. The
following types basically need to be added:
On
Microsoft Servers, there's a HTTP header tab on the Management Console. On
Apache servers, you use an .htaccess file. When
you are accessing a secure service (using WTLS) the data is sent encrypted to
the WAP gateway. The gateway decrypts it and encrypts it using SSL before
passing it on to the web server. When the data returns, it will be decrypted and
encrypted using WTLS before being sent to your WAP device. By combining the web server
and the WAP gateway it is possible to enhance the overall security in
these operations involved. WAP Servers and Gateways
A list of Gateways/Servers can be found at
(Dedicated to providing comprehensive information to mobile computing community of IT professionals, user organizations, and vendors) |
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