1 research outputs found
Tradeoff between Ergodic Rate and Delivery Latency in Fog Radio Access Networks
Wireless content caching has recently been considered as an efficient way in
fog radio access networks (FRANs) to alleviate the heavy burden on
capacity-limited fronthaul links and reduce delivery latency. In this paper, an
advanced minimal delay association policy is proposed to minimize latency while
guaranteeing spectral efficiency in F-RANs. By utilizing stochastic geometry
and queueing theory, closed-form expressions of successful delivery
probability, average ergodic rate, and average delivery latency are derived,
where both the traditional association policy based on accessing the base
station with maximal received power and the proposed minimal delay association
policy are concerned. Impacts of key operating parameters on the aforementioned
performance metrics are exploited. It is shown that the proposed association
policy has a better delivery latency than the traditional association policy.
Increasing the cache size of fog-computing based access points (F-APs) can more
significantly reduce average delivery latency, compared with increasing the
density of F-APs. Meanwhile, the latter comes at the expense of decreasing
average ergodic rate. This implies the deployment of large cache size at F-APs
rather than high density of F-APs can promote performance effectively in
F-RANs