Towards 5G

6 Proactive Caching in 5G Small Cell Networks

Ejder Baştuğ,¹ Mehdi Bennis,² and Mérouane Debbah¹

¹ CentraleSupélec, France

² Centre for Wireless Communications, University of Oulu, Finland

6.1 Small Cell Networks: Past, Present, and Future Trends

Smartphones have exponentially increased the traffic load in current cellular networks, a trend that is showing no signs of slowing down [1, 2]. It is now well understood that a very effective way to increase network capacity is making cells smaller, reducing the distance to the users [3]. Indeed, cell densification has gone from the order of hundreds of square kilometers back in the 1980s to a fraction of a square meter or less with the advent of hotspots. There has recently been a great interest in deploying relays, distributed antennas, and small cellular access points, such as micro, pico, and femto cells, in residential homes, subways, enterprises, and hotspot areas. These network architectures, which are either operator-deployed or user-deployed, are referred to heterogeneous networks (HetNets) or small cell networks (SCNs) [3, 4]. By deploying additional network nodes within local-area range and making the network closer to end-users, small cells can significantly improve spatial reuse and coverage, boost capacity, and offload traffic more efficiently [4].

There is a comprehensive literature on the topic of HetNets and SCNs, tackling aspects such as interference management, cell association, stochastic network modeling, ...