Now that we have looked at the radio interfaces, protocols, and security issues involved in a wireless LAN, it is time to see what it takes to bring all of these elements together to actually build one. While setting up a small-scale WLAN might simply require the installation of a single access point (AP) and configuring a few NICs, a large-scale network will involve significant planning.

The design of a wireless LAN must address three primary issues: capacity, coverage, and ongoing operations. In this chapter, we will look at the first two, which are the major concerns in the design and implementation phase. In the final chapter, we will discuss the issues involved in maintaining and operating a voice-capable WLAN.

The initial concern in implementing a wireless LAN was providing coverage or ensuring that a user can get wireless access from any location within the facility. The problem is that the wireless LAN connection must also support the performance requirements of the application. A low transmission rate can be as bad as no service at all, and it is far more frustrating. To ensure capacity, we need to look at the number of users who will be active in each cell, determine their total requirements, and then arrange the cells to meet those requirements.

In this chapter, we will begin by reviewing some of the important characteristics of wireless LANs. Then we will look at the design variables we can control to ensure capacity and coverage. We will also list...