Wireless communication networks have been around for centuries: the use of smoke signals from mountain tops to alert tribal members of impending danger; waving lanterns at night to signal neighbors of the arrival of unexpected or uninvited visitors. Broadcast radio and television are more contemporary examples of wireless communication, as are cellular and cordless telephones, garage door openers, and automobile car locks. Some of these examples use radio frequencies (RF), some use "invisible" light in the infrared (IR) spectrum.

Wireless Network Infrastructures

The wireless data industry is still working out the bugs in developing and building data transmission networks and agreeing on standards and protocols. While there are several competing visions, many experts believe that the growing market for wireless data will support many networks and protocols, such as the following:

• Global Systems for Mobile (GSM) Communication is a digital cellular or Personal Communications Services (PCS...