A Bee Colony-based Algorithm for Micro-cache Placement Close to End Users in Fog-based Content Delivery Networks

摘要

Fog-based Content Delivery Networks (CDNs) distribute contents from origin servers to cloud replica servers and to fog caches. Some of these fog caches may be located on Set-top Boxes (STBs) close to end users, assuming that the STBs can host micro-caches. This can greatly reduce latency. Network function virtualization (NFV) is a technology that can be used in fog systems. NFV-enabled STBs can therefore host micro-caches implemented as virtual network functions (VNFs). Appropriate placement mechanisms are needed to place these micro-caches to improve end-users' QoS in terms of latency while still minimizing cost. In this paper, this placement problem is modeled as an optimization problem. A bee colony-based algorithm is suggested to find the placement that minimizes an aggregation of latency and micro-cache storage cost. The simulation results show an improvement in the aggregated latency and cost when the proposed algorithm is deployed.