The RatNest Routing Protocol for Ad-Hoc Circuits Over Fixed Radio Networks
Scott A. Mitchell · 2009
Abstract — We propose the RatNest protocol for low-overhead ad-hoc routing over a small wireless radio network in support of certain novel communication patterns and nodes. Nodes have fixed position in an urban environment and have up to five dedicated wireless radio channels to nearby nodes. Links vary in quality and reliability. The protocol provides for the quick establishment and repair of routes to support circuit-like communication of both streaming video and sensor-chirps. As in link-state routing, our protocol stores a graph representation of the network at each node, annotated with transient information about the network state. Transient information is gathered using both pro-active and reactive mechanisms. To establish a circuit, a shortest-latency or highest-throughput path is computed locally on this graph, then the route is locally adapted and verified on the actual network. In this paper we focus on the main algorithms of the protocol and some analysis. We do not report simulation results in this paper, but we have implemented a prototype in C++ and integrated it into OPNET Modeler. low-bandwidth (but latency-sensitive) sensor chirps. We consider two metrics for paths: for sensor chirps we use path length, the sum of link weights along the path; for streaming data we use bottleneck, the maximum weight over all links along the path. The structured society of naked mole rat colonies provides some metaphors and inspiration for RatNest, but we are not “bio-inspired”[12] in the sense of accurately implementing in software specific natural activity. Nodes of the network are called “nests, ” after the hub-like nests of naked mole rats. Unless otherwise stated, features described in this paper have been implemented in a C++ prototype integrated with