Cache-assisted amorphous cell association for heterogeneous content delivery networks

In future cellular networks, network densification and mobile video traffic are main driving force for a fundamental paradigm shift. The most critical one regarding these issues is high throughput requirement regardless of user location and type of contents. However, heterogeneity and content-centrality make utilization of network resource more challenging to satisfy fairness and efficiency simultaneously. Cache-assisted amorphous cell association (CA 2 ) is a solution for heterogeneous content delivery networks (HetCDNs) where traffic load and user requests are both nonuniform and unbalanced. In peak-traffic hours, base stations adjust their bias for load balancing and multicast to guarantee fairness for low-rate users. In off-peak hours, base stations optimize their caches to boost quality of experience (QoE) for frequently requested video contents. Overall, amorphous-shaped cell is formed by distributed optimization of cell association and caching. In this paper, we propose CA 2 scheme and develop distributed algorithms based on decomposition method to enhance spectral efficiency and flexibility. Numerical results demonstrate the effectiveness of our scheme in HetCDNs.