Nation scale mobile ad hoc network for normally isolated topologies

When network infrastructure is down after disasters such as hurricane Maria, inaccessible due to extreme censorship or nonexistent in remote areas without infrastructure, novel solutions for large scale delay tolerant communications are needed. Nation Scale Mobile Ad Hoc Network, or NSHoc, enables smartphone users to request and receive content via opportunistic encounters at nation scale with no prior knowledge of network members and in sparse topologies where individual nodes may remain isolated for minutes or even hours at a time. We call such sparse topologies normally isolated. It does so by leveraging mobile ad hoc networks that rely on opportunistic encounters between users to distribute content. We use a custom simulator to test the system over two nation scale topologies: Puerto Rico and Syria. With 10K users, NSHoc can deliver over 95% of the requested content to over 97% of users in 143 locations spread throughout Puerto Rico in less than 5 hours on average with a total throughput of.42 pieces of content per second. Significantly, these results are not simply the consequence of popular content being cached. We demonstrate that requests for unpopular content are also satisfied due to the benefits of ubiquitous caching. In addition, we show that NSHoc remains performant across a variety of topologies, mobility models, and content distributions. No known prior work considers such large scale, sparse topologies. This work shows that MANETs are an attractive alternative for distributing content at nation scale in the face of infrastructure loss even when users are normally isolated.