  In the performance analyses of wireless networks, asymptotic quantities and
properties often pro- vide useful results and insights. The asymptotic analyses
become especially important when complete analytical expressions of the
performance metrics of interest are not available, which is often the case if
one departs from very specific modeling assumptions. In this paper, we consider
the asymptotics of the SIR distribution in general wireless network models,
including ad hoc and cellular networks, simple and non-simple point processes,
and singular and bounded path loss models, for which, in most cases, finding
analytical expressions of the complete SIR distribution seems hopeless. We show
that the lower tails of the SIR distributions decay polynomially with the order
solely determined by the path loss exponent or the fading parameter, while the
upper tails decay exponentially, with the exception of cellular networks with
singular path loss. In addition, we analyze the impact of the nearest
interferer on the asymptotic properties of the SIR distributions, and we
formulate three crisp conjectures that -if true- determine the asymptotic
behavior in many cases based on the large-scale path loss properties of the
desired signal and/or nearest interferer only.
