  Stringent mobile usage characteristics force wire- less networks to undergo a
paradigm shift from conventional connection-centric to content-centric
deployment. With respect to 5G, caching and heterogeneous networks (HetNet) are
key technologies that will facilitate the evolution of highly content- centric
networks by facilitating unified quality of service in terms of low-latency
communication. In this paper, we study the impact of transceiver caching on the
latency for a HetNet consisting of a single user, a receiver and one
cache-assisted transceiver. We define an information-theoretic metric, the
delivery time per bit (DTB), that captures the delivery latency. We establish
coinciding lower and upper bounds on the DTB as a function of cache size and
wireless channel parameters; thus, enabling a complete characterization of the
DTB optimality of the network under study. As a result, we identify cache
beneficial and non-beneficial channel regimes.
