Background Information

Communication between a common web server and a WAP-enabled wireless device, in principle, is much the same as that between the web server and the traditional pc-based browser , but with one additional step.

This extra step involves the transfer of information by a WAP gateway. WAP gateways serve as intermediaries between the client-based wireless browser and an information server.

This process is illustrated below:

Consider a typical example of the communications process, as illustrated in the above example: Assume we have defined a deck of two cards. A wireless-device user requests the deck (document). The sequence of events that would take place as a result of this request would be as follows:

1. The request is sent to the WAP gateway under the WAP protocol. The WAP gateway, under the "control" of the WAP device, performs a typical URL request, using HTTP protocol.
2. The URL request is transmitted via the Internet to the WAP device's IP address. (The mobile operator assigns the device its IP address.)
3. The request reaches its final destination – that being a web server. The server, in turn, reads the header and processes the WAP document request. PHP code contained within this document is compiled and formatted as necessary (that is, within the document).
4. The located (and processed) WAP document (deck) is routed back via the WAP gateway, where its contents are compressed into binary data and sent to the WAP-enabled device.