ABSTRACT
This chapter discusses the uncertainties as well as time varying behaviors of the wireless channels in a mesh network environment. It begins with a discussion of common environment noises in the networked control system. Then it elaborates on the changing temperatures of the surrounding harsh environment which significantly results in path fading and overall wireless signal quality. Signal-to-noise ratio (SNR) is also one important factor that determines the quality of a wireless network. One common source that creates significant noise to wireless instruments is the thermal temperature surfaces nearby industrial instruments. As noise always persists in the environment, in an industrial network, due to the harsh nature of the surrounding, the SNR ratio can significantly differ from one wireless node to another. In the real world, various interferers do exist in process plants such as multipath fading, noise from machinery equipment, non-line of sight communication, object blocking.
