Using Context Ontologies for Addressing and Routing in Mobile Ad Hoc Networks

This paper presents a new way of addressing and routing for mobile ad hoc networks on the basis of contextual information such as air pressure, brightness, wind direction and strength, or GPS position. The most common use case of context-based addressing is group communication: A participant sends a message to an a priori unspecified set of recipients, but indicates the context in which the message could be useful for a potential receiver. In contrast to infrastructure networks the sender no longer designates the receiver of its message with a distinct identifier. Instead, each recipient using his local context decides by himself, whether the message is useful for him and whether it should be sent out again. The modeling of the necessary application knowledge is done as ontologies in OWL (web ontology language). As an example scenario, a wind gust warning on highways using a vehicular ad hoc network (VANET) is described: the warning message should be sent to all vehicles on the same route containing the place where the wind was detected. The models are applied in a prototypical example scenario in order to show the performance of the approach through a simulation, using the JiST/SWANS simulator for mobile ad hoc networks. The results show that the number of messages that are necessary to warn all vehicles in a given environment of the wind danger can be reduced by half - as opposed to a simple flooding of the network.