Knowledge Systems Institute                                                                                                BA513 Multi-media Information Systems    

                                                                        Wireless bank and WML  

                                                                                                                                            Prof : Dr. S.K Chang

                                                                                                                                         Student : Jin Lung Chen  

How does a WAP device connect to the internet?

The normal implementation of a WAP scenario looks pretty much like this:

        In the figure above, starting from the left, you'll find the mobile WAP device attached to the mobile network (GSM, CDDA, etc) which dials the modem attached to a dial-in server (RAS, or Remote Access Service). This server gives the WAP device access to the protocols it needs. These are the same lower level protocols as a normal Internet Service Provider will give you. This is known as PPP or Point-to-Point Protocol.

These protocols are used to access the next step in the chain, the WAP gateway, in this figure hosted by the mobile operator. The WAP gateway is the link between the wireless and the "web" world, basically giving the WAP device access to the common internet.

(1) Wireless application

             IntegrationWireless develops applications that support WAP/WML, the standard for wireless data access. This means that anyone with a WAP-phone or handheld computer with wireless data access can use our applications. The devices support by the applications, which  run on phones from Nokia, Ericsson, Motorola, and almost any other wireless device.

(2) WAP gateway


       A WAP gateway is a piece of software that has several functions in the "chain" between the WAP device and the web server. These functions are in general:

*Converting the markup language (WML) from textual format to tokenized (binary/compressed) format which is    readable by the WAP device.
*Translating the requests from the WAP device to HTTP requests for the "web" world.
*Convert between the SSL encryption used in the "web" world and the WTLS encryption used in the WAP world.
*Convert between the "transport" protocol of the "web", TCP, and that of the WAP world, WDP.

The reason for the conversion from texual WML to tokenized WML is to reduce bandwidth usage. A WAP device's WML browser can only read tokenized WML.

(3) Web sever

        On the internet, there is a normal "web" server which in this case holds both WAP and "web" contents, which now receives the request to send out the contents located at the http://wap.colorline.no/ URL. Also note the normal "web" browser at the lower part of the figure. The web server, depending on which type of browser it is talking to (WAP or "web"), sends out WAP, represented by the blue line, or "web" content represented by the green line.

(4) URL

         The URL, the WML browser, when receiving the tokenized WML code renders the contents on the WAP device's display to present a card for the user.