TABLE OF CONTENTS Wireless LAN (WLAN) equipment is tested in various types of environments: open-air, chambered (screened room or anechoic), or conducted. The environment selected has a Significant impact on what types of tests can be done and what type of test instruments are used. This chapter treats the different test environment types and their characteristics. Also, it describes when each type of environment is used, and what problems are faced by people using each type of environment. Repeatability of measurements will be a key focus of this chapter.
Wired LAN testing rarely bothers with specifying any form of physical environment. Cables and optical fibers work equally well whether coiled up in a tangle or stretched out behind walls and ceilings. Hubs, switches, routers, and computers do not care whether they are mounted vertically or horizontally. The materials used to construct the walls and ceilings do not have any impact on the test results. Wired LANs can be run without noticeable impact in close proximity to most electronic devices optical fiber LANs can be run in even extremely electronics-hostile environments without degradation.
WLAN performance, on the other hand, is Significantly affected by changes in the environment. For example, place a large metal can over an access point (AP); the connectivity between the AP and a nearby client will fail immediately. The distance between the AP and its clients is also Significant. Things work much better in open-air or low-metal environments (e.g., homes made of wood and wallboard) rather...
