Recent progress in routing protocols of mobile opportunistic networks: A clear taxonomy, analysis and evaluation

Mobile opportunistic networks provide an efficient solution to implement the intensive perception and ubiquitous interconnection in Internet of Things. Routing selection is one of the fundamental components focusing on data communication in intermittently connected scenarios, it therefore captures great interests from research community. This work surveys recent progress in opportunistic routing protocols (ORPs). In general, they can be roughly classified by two underlying principles: Zero-information and information-rich. The Epidemic acts as representative of zero-information ORPs, in which a node does not require any prior information about the contact knowledge with others. The original idea of information-rich ORPs is that it records the historical contact information or social features of nodes, and then this knowledge is used to guide routing decisions. This paper elaborates on these ideas and evaluates several classical protocols from the perspective of data and control planes. Specifically, we give an integrative analysis of zero-information ORPs in term of average number of hops per packet. A qualitative analysis on information-rich ORPs and a quantitative comparison including the cumulative packet delivery ratio and energy efficiency are also presented. We finally point out some promising research directions towards lightweight but smart routing protocols.