An ICN/SDN-Based Network Architecture and Efficient Content Retrieval for Future Satellite-Terrestrial Integrated Networks

With the tremendous increase in the amount of network contents and emerging applications, traditional network architecture starts to exhibit management and efficiency problems. The evolving STIN, as a combination of satellite networks and terrestrial networks, also faces similar obstacles. To address this challenge, technologies like ICN and SDN, which were initially proposed for terrestrial networks, could provide viable and promising solutions in STIN. In this article, we propose a novel architecture to provide flexible management and efficient content retrieval for STIN. Our architecture consists of a three-layer satellite network in which satellites of each layer are assigned to different functionalities. In order to achieve compatibility with ICN, we also design a new on-board switch based on protocol oblivious forwarding switch. In so doing, the proposed architecture inherits the advantages of ICN and SDN. Additionally, concerning the issue of the most traffic contribution in content retrieval applications, we propose a simple yet effective cooperative content retrieval scheme for terrestrial users. Furthermore, to make the best use of in-network caching and achieve further efficiency improvement of content retrieval, a cooperative caching scheme and a coded caching scheme are also proposed. The feasibility of these caching schemes is analyzed, and numerical evaluations show that the proposed content retrieval schemes in this architecture can achieve significant traffic load reduction.