Offline Downloading in China: A Comparative Study

摘要

Although Internet access has become more ubiquitous in recent years, most users in China still suffer from low-quality connections, especially when downloading large files. To address this issue, hundreds of millions of China's users have resorted to technologies that allow for "offline downloading", where a proxy is employed to pre-download the user's requested file and then deliver the file at her convenience. In this paper, we examine two typical implementations of offline downloading: the cloud-based approach and the smart AP (access point) based approach. Using a large-scale dataset collected from a major cloud-based system and comprehensive benchmarks of popular smart APs, we find that the two approaches are complementary while also being subject to distinct performance bottlenecks. Driven by these results, we design and implement a proof-of-concept middleware called ODR (Offline Downloading Redirector) to help users get rid of performance bottlenecks. We feel that offline downloading has broad applicability to other areas of the world that lack broadband penetration. By deploying offline downloading technologies, coupled with our proposed ODR middleware, the Internet experiences for users in many parts of the world can be improved.