  This paper studies the gains, in terms of served requests, attainable through
out-of-band device-to-device (D2D) video exchanges in large cellular networks.
A stochastic framework, in which users are clustered to exchange videos, is
introduced, considering several aspects of this problem: the video-caching
policy, user matching for exchanges, aspects regarding scheduling and
transmissions. A family of \emph{admissible protocols} is introduced: in each
protocol the users are clustered by means of a hard-core point process and,
within the clusters, video exchanges take place. Two metrics, quantifying the
"local" and "global" fraction of video requests served through D2D are defined,
and relevant trade-off regions involving these metrics, as well as
quality-of-service constraints, are identified. A simple communication strategy
is proposed and analyzed, to obtain inner bounds to the trade-off regions, and
draw conclusions on the performance attainable through D2D. To this end, an
analysis of the time-varying interference that the nodes experience, and tight
approximations of its Laplace transform are derived.
