  Today's mobile data traffic is dominated by content-oriented traffic. Caching
popular contents at the network edge can alleviate network congestion and
reduce content delivery latency. This paper provides a comprehensive and
unified study of caching and delivery techniques in wireless radio access
networks (RANs) with caches at all edge nodes (ENs) and user equipments (UEs).
Three cache-aided RAN architectures are considered: RANs without fronthaul,
with dedicated fronthaul, and with wireless fronthaul. It first reviews in a
tutorial nature how caching facilitates interference management in these
networks by enabling interference cancellation (IC), zero-forcing (ZF), and
interference alignment (IA). Then, two new delivery schemes are presented. One
is for RANs with dedicated fronthaul, which considers centralized cache
placement at the ENs but both centralized and decentralized placement at the
UEs. This scheme combines IA, ZF, and IC together with soft-transfer
fronthauling. The other is for RANs with wireless fronthaul, which considers
decentralized cache placement at all nodes. It leverages the broadcast nature
of wireless fronthaul to fetch not only uncached but also cached contents to
boost transmission cooperation among the ENs. Numerical results show that both
schemes outperform existing results for a wide range of system parameters,
thanks to the various caching gains obtained opportunistically.
