  The dynamics of interference over space and time influences the performance
of wireless communication systems, yet its features are still not fully
understood. This article analyzes the temporal dynamics of the interference in
Poisson networks accounting for three key correlation sources: the location of
nodes, the wireless channel, and the network traffic. We derive expressions for
the auto-correlation function of interference. These are presented as a
framework that enables us to arbitrarily combine the three correlation sources
to match a wide range of interference scenarios. We then introduce the
interference coherence time - analogously to the well-known channel coherence
time - and analyze its features for each correlation source. We find that the
coherence time behaves very different for the different interference scenarios
considered and depends on the network parameters. Having accurate knowledge of
the coherence time can thus be an important design input for protocols, e.g.,
retransmission and medium access control.
