The main pieces of a WAP (Wireless Application protocol) solution include : Content, Content Server, TCPIP/HTTP, WAP Gateway, Bearer, and WAP Device.

Content
The important information you need to access when you are away from your computer and the office LAN, eg :

• "Availability of spare parts" for engineer working at customer's site
• "E-mail message with new prices" for a manager visiting potential customer
• "Shipment status" of a delayed order for salesman meeting a customer
• "Phone number & address of restaurant" if you are late for your first date !

Content Server
This takes your content (information) and formats it into the WML Cards that the WAP Device can understand. WML (Wireless Markup Language) Cards are very similar to the HTML Pages we use on the Web.

Some Content Servers are dedicated to a certain role. eg Infinite InterChange can be used immediately to provide WAP access to your E-mail mailbox.

Other Content Servers use general-purpose Web Servers such as IIS or Apache. These require the customer to build their own custom applications, such as the "Query Order Status" application mentioned above.

TCPIP / HTTP
The WML Cards are carried across a TCPIP network (the company's Intranet, or the public Internet) in the same way as Web pages.

WAP Gateway (or "WAP Proxy").
The WML Cards cannot be delivered directly to a WAP Device. Instead they must pass through a WAP Gateway, which translates them into a compressed "byte-code" format that the WAP Device understands. This compression helps to get the best performance from the WAP Device.

Personal WAP users are likely to use their Mobile Operator's WAP Gateway. Corporate users, and WAP Content providers such as Banks are likely to need better control and / or security. They may choose to install their own WAP Gateway such as WAPLite.

Bearer
The Bearer is the communications path between the WAP Device and the WAP Gateway. The three most common Bearers are:

• SMS. Available on most mobile phones, but performance can be unpredictable.
• CSD. (Circuit Switched Data). Very similar to dialling from a home PC to an ISP. Disadvantage is that while it is used, you cannot make or receive voice calls.
• Packet. The ideal solution, but not yet widely available.

WAP Device
Usually a WAP Handset such as the Nokia 7110, but also includes PDA's such as the Ericsson MC318. Software Vendors are also developing WAP Browsers that will let you use existing devices such as a Palm Pilot to access WAP services.