Delay-tolerant broadcasting

There are many asynchronous communication situations for which the prevalent continuous connectivity paradigm is not needed. Communication with a fair delay tolerance may instead be provided by intermittent store-and-forwarding between nodes. This paper proposes a design for an open, receiver-driven broadcasting system that relies on delay-tolerant forwarding of data chunks through mobility of wireless nodes. The system provides public broadcast channels, which may be openly used for both transmission and reception. We show by analysis and simulation under benchmark mobility models that a delay-tolerant broadcast channel has both a sufficiently high throughput and reach to be interesting as a competitive alternative to the regulated wireless broadcast channel. The analysis is based on a queuing model to study the interactions among the mobile nodes in a street. The simulations complement this analysis for mobile nodes moving on a square according to benchmark mobility models. Finally, we present the design of, and experiences with, a proof-of-concept prototype. Index Terms--Broadcasting, communication systems, computer networks, mobile communication, networks, personal communication networks, routing.