  The wide deployment of wireless industrial networks still faces the challenge
of unreliable service due to severe multipath fading in industrial
environments. Such fading effects are not only caused by the massive metal
surfaces existing within the industrial environment but also, more
significantly, the moving objects including operators and logistical vehicles.
As a result, the mature analytical framework of mobile fading channel may not
be appropriate for the wireless industrial networks especially the majority
fixed wireless links. In this paper, we propose a qualitative analysis
framework to characterize the temporal fading effects of the fixed wireless
links in industrial environments, which reveals the essential reason of
correlated temporal variation of both the specular and scattered power.
Extensive measurements with both the envelop distribution and impulse response
from field experiments validate the proposed qualitative framework, which will
be applicable to simulate the industrial multipath fading characteristics and
to derive accurate link quality metrics to support reliable wireless network
service in various industrial applications.
