Cooperatively Constructing Cost-Effective Content Distribution Networks upon Emerging Low Earth Orbit Satellites and Clouds

Internet content providers typically exploit cloud-based content delivery/distribution networks (CDNs) to provide wide-area data access with high availability and low latency. However, from a global perspective, a large portion of users still suffer from high content access latency due to the insufficient deployment of terrestrial cloud infrastructures.This paper presents StarFront, a cost-effective content distribution framework to optimize global CDNs and enable low content access latency anywhere. StarFront builds CDNs upon emerging low Earth orbit (LEO) constellations and existing cloud platforms to satisfy the low-latency requirements while minimizing the operational cost. Specifically, StarFront exploits a key insight that emerging mega-constellations will consist of thousands of LEO satellites equipped with high-speed data links and storage, and thus can potentially work as "cache in space" to enable pervasive and low-latency data access. StarFront judiciously places replicas on either LEO satellites or clouds, and dynamically assigns user requests to proper cache servers based on constellation parameters, cloud/user distributions and pricing policies. Extensive trace-driven evaluations covering geo-distributed vantage points have demonstrated that: StarFront can effectively reduce the global content access latency with acceptable operational cost under representative CDN traffic.