BUBBLE Rap: Social-Based Forwarding in Delay-Tolerant Networks

The increasing penetration of smart devices with networking capability form novel networks. Such networks, also referred as pocket switched networks (PSNs), are intermittently connected and represent a paradigm shift of forwarding data in an ad hoc manner. The social structure and interaction of users of such devices dictate the performance of routing protocols in PSNs. To that end, social information is an essential metric for designing forwarding algorithms for such types of networks. Previous methods relied on building and updating routing tables to cope with dynamic network conditions. On the downside, it has been shown that such approaches end up being cost ineffective due to the partial capture of the transient network behavior. A more promising approach would be to capture the intrinsic characteristics of such networks and utilize them in the design of routing algorithms. In this paper, we exploit two social and structural metrics, namely centrality and community, using real human mobility traces. The contributions of this paper are two-fold. First, we design and evaluate BUBBLE, a novel social-based forwarding algorithm, that utilizes the aforementioned metrics to enhance delivery performance. Second, we empirically show that BUBBLE can substantially improve forwarding performance compared to a number of previously proposed algorithms including the benchmarking history-based PROPHET algorithm, and social-based forwarding SimBet algorithm.

1 Introduction

We envision a future in which a multitude of devices carried by people are dynamically networked. We aim to build pocket switched networks (PSN) [1], a type of delay-tolerant networks (DTN) [2] for such environments. A PSN utilizes contact opportunities to allow humans to communicate without network infrastructure. We propose an efficient data forwarding mechanism over time evolving graphs of the PSN [3], that copes with dynamical, repeated disconnection, and rewiring. With such scenarios, end-to-end delivery through traditional routing algorithms is rarely applicable.