  Fog computing based radio access network is a promising paradigm for the
fifth generation wireless communication system to provide high spectral and
energy efficiency. With the help of the new designed fog computing based access
points (F-APs), the user-centric objectives can be achieved through the
adaptive technique and will relieve the load of fronthaul and alleviate the
burden of base band unit pool. In this paper, we derive the coverage
probability and ergodic rate for both F-AP users and device-to-device users by
taking into account the different nodes locations, cache sizes as well as user
access modes. Particularly, the stochastic geometry tool is used to derive
expressions for above performance metrics. Simulation results validate the
accuracy of our analysis and we obtain interesting trade-offs that depend on
the effect of the cache size, user node density, and the quality of service
constrains on the different performance metrics.
