Environmental electromagnetic emissions
may also affect wireless transmission, such as those produced
by large motors and electrical discharges. Thermal noise can
negatively affect transmission, as can the Doppler-shift induced
by rapidly moving equipment. Such interference is often
transient in nature, resulting in bursts of data and affecting the
reliability and determinability of the transmission. Wireless
transmission radii are limited by transmission strength and
negatively affected by path-fading, the degree of which is
determined by environmental factors. This makes it difficult to
design a wireless network for industrial use without first determining
the path-fading coefficient throughout the intended
usage area.