An Overview of Opportunistic Routing in Mobile Ad Hoc Networks

The US Defense Department has been investigating deployment architectures for Disruption Tolerant Networking (DTN) technologies into tactical Internet Protocol (IP) networks. Opportunistic routing protocols have recently emerged as promising routing protocols in delay tolerant networks. In this paper, we discuss some of the motivations for opportunistic routing, and identify several key challenges in designing an efficient opportunistic routing protocol. We review several representative opportunistic routing protocols, including Extremely Opportunistic Routing protocol, Time Aware Opportunistic Routing (TAO), the Simple Opportunistic Adaptive Routing protocol, the Resilient Opportunistic Mesh Routing, the Multipath Code Casting, Optimized Overlay-based Opportunistic Routing, Social-aware opportunistic routing protocol (dLife), and the social relation opportunistic routing (SROR), discussing the protocols' key idea, main assumptions, complexity, advances and disadvantages. We identify open research issues in opportunistic routing.