Empirical evaluation of hybrid opportunistic networks

In this paper, we study the utility of opportunistic communication systems with the co-existence of network infrastructure using three real experimental deployments. We study how some important performance metrics change with varying degrees of infrastructure and mobile nodes willing to participate in the opportunistic forwarding. In doing so, we observe phase transitions in the utility of infrastructure and opportunistic forwarding respectively at different points in the design space. We discuss the implications that this has for the design of future network deployments and how this observation can be used to improve network performance, while keeping cost at a minimum. To the best of our knowledge, this is the largest scale of experimental evaluations of hybrid opportunistic networks. It provides empirical evaluations to the large body of theoretical work that has been done in the past and insights for future research.