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 (CA2) 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, amorphousshaped cell is formed by distributed optimization of cell association and caching. In this paper, we propose CA2 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.