PLI-Sync: Prefetch Loss-Insensitive Sync for NDN Group Streaming

摘要

In this paper we explore solutions to robust group communication in disadvantaged wireless networks that exhibit low bandwidth, high packet losses, and frequent or even permanent network partitions. More specifically, we propose a group communication protocol based on Named Data Networking (NDN). By design, NDN’s in-network caching and stateful forwarding plane can help improve data delivery robustness in disadvantaged networks, but when content is generated with dynamic rates, an efficient, low-overhead synchronization protocol is needed to inform group members to fetch newly generated content promptly. In this paper, we describe the Prefetch Loss-Insensitive Sync (PLI-Sync) protocol for group communication in highly disadvantaged networks. PLI-Sync combines optimistic content pre-fetching with new content notification via sync, and addresses the challenges of how to distinguish wireless packet losses from mobility-induced disconnections, and between data availability and retrievability. Our evaluations show that leveraging the interplay between optimistic pre-fetching and a low rate sync protocol can significantly reduce communication overhead compared to relying on sync protocols alone, while maintaining low data fetching latency and robust delivery in a variety of wireless conditions and traffic load settings.