SmartSharing: A CDN with Smart Contract-based Local OTT Sharing

A content delivery network (CDN) uses distributed cache servers to reduce the content delivery latency to end users. In recent years, CDN providers adopt a new content caching strategy that allows end users to share their storage/bandwidth resources. Two core questions need to answer in this strategy: (1) how to incentivize end users to contribute their resources? (2) how to facilitate transparent, secure content trading among end users?We propose a new CDN solution, called SmartSharing, where users contribute their over-the-top (OTT) devices as mini-cache servers. To incentivize end users to contribute resources, SmartSharing uses game theory and an Expectation-Maximization (EM) algorithm to determine the content delivery schedule and the pricing scheme. To facilitate content trading among end users, SmartSharing uses smart contracts in Ethereum to create a transparent and safe transaction platform. We thoroughly evaluate the performance of SmartSharing with real-world trace-driven simulation as well as a prototype using content metadata and the derived pricing scheme.