  We show that, for independent interfering sources and a signal link with
exponentially distributed received power, the total probability of outage can
be decomposed as a simple expression of the outages from the individual
interfering sources. We give a mathematical proof of this result, and discuss
some immediate implications, showing how it results in important
simplifications to statistical outage analysis. We also discuss its application
to two active topics of study: spectrum sharing, and sum of interference powers
(e.g., lognormal) analysis.
