User manual

Appendix A: Path Evaluation Information A-11
Moseley SL9003Q 602-12016 Revision G
Over a year, the fade probability due to climate is given by:
ryr = b x rm
Where,
b (climate factor)
= 1/2 for Gulf coast or similar hot, humid areas.
= 1/4 for normal interior temperate or northern regions.
= 1/8 for mountainous or very dry areas.
By combining the three equations and noting that Undp is equal to the actual fade probability,
for a given fade margin F, we can write:
U
ndp
= ryr x 10-F/10 = b x rm x 10-F/10
or
U
ndp
= a x b x 2.5 x 10-6 x f x 10D3 x 10-F/10
See Table A-6 for the relationship between system reliability and outage time.