Cooperative Base Station Caching and X2 Link Traffic Offloading System for Video Streaming Over SDN-Enabled 5G Networks

This paper presents a cooperative base station caching and X2 link traffic offloading system for video streaming services over software-defined networking (SDN)-enabled 5G networks. The goal of the proposed system is to provide seamless video streaming services to users while alleviating the backhaul traffic in the cellular network by effectively caching contents at the base stations and appropriately offloading parts of the backhaul traffic to X2 links. In the proposed system, the main functionalities of content-centric networking (CCN) are deployed at the base stations to take advantage of the attributes offered by CCN such as in-network caching and name-based forwarding. Furthermore, SDN technology is adopted not only to solve the practical issues of CCN, but also to control network resources efficiently. The proposed system is designed to determine near optimal caching positions and routes for all content in two phases to reduce the computational complexity for the real-time processing. The proposed system is fully implemented using well-known open sources, e.g., CCNx and ONOS, and ${\mathrm{C/ C}}+ +$C/C++. Finally, the system is examined in real wireless network environments. During the experiment, the proposed system can reduce cellular traffic by more than 13 percent over existing traffic offloading algorithms.