XML and ASP.NET

The IT industry is plagued by protocols. It seems that almost every year, dozens of new technologies and protocols are defined. It can be a challenging task to keep up with all of them. So, why do we need another protocol?

The answer is not that technical. There's no big thesis on why we need WAP except for the fact that most Internet and network protocols are for PCs in general or larger capacity systems, not the lightweight processor and display area that challenge mobile devices.

Most of the protocols make many assumptions about the environment in which they operate . These assumptions include the type of network the protocol runs on, normally from the viewpoint of bandwidth and reliability, as well as the devices that will access the services offered by the protocols.

The following list outlines some of the requirements a PC needs when using the HTTP protocol:

• Constant bandwidth capability; speeds commonly in excess of 100kbps

• High reliability of data transfer

• A constant connection to work

Compare those requirements with the requirements of a mobile phone using WAP:

• Restricted bandwidth; in a many cases, no more 1.5k.

• High reliability when connected.

• Devices can rarely stay connected for long due to their method of data transfer. (For example, everyone's been cut off when using a mobile phone and everyone's had bad reception from time to time. You can imagine what that can do to sent data.)

As you can see, mobile devices have extra issues to deal with that a PC does not. This is a great segue into the key differences between PC applications and mobile-device applications. After all, it's what this chapter is about.