A WAP Server is nothing more than a normal web server and a WAP gateway-like device built into one. I personally think the term "WAP server" is very confusing. Many people think that you must have a WAP server in order to serve WAP content, but this is NOT the case. WAP content is served from any normal web server!.

So what is the point of the WAP server? Well, when it comes to WAP security, the WAP server can plug a few holes that are currently unplugged in the WAP environment.

Since the WAP server contains a gateway, the third party gateway usually hosted by the mobile operator can be skipped, and the host of the WAP content will have full control over the encrypted stream.

Note that if you want your users to be able to access your WAP site via your WAP server gateway, they will need to reconfigure their phones, and most of them will have to do it manually.

Chapter 1 in "Professional WAP" from Wrox