Bidirectional, user-centered Car2X-Communication: The Pull Paradigm
The group has profound experience in advanced Car2X Communication technologies, i.e. communication between vehicles as well as of vehicles with their surroundings. In this context a novel paradigm for Car2X Communication networks has been developed up by introducing interactivity to the ad-hoc community. In the figure below, this Pull Paradigm is compared to the established Push Paradigm.
Fig 1: Pull Paradigm
The Push Paradigm is unidirectional and starts with an event somewhere at an information source within the ad-hoc network. This event, a car crash for example, is then broadcast as fast as possible. On receipt, cars perform a relevance check and, if positive, the event is presented to the user. Furthermore, cars forward this event even if it is not relevant in the local context. The Pull Paradigm, however, is bidirectional and starts at the user who is proactively requesting information from the ad-hoc network.
In contrast to the Push Paradigm, a discovery procedure is mandatory in order to locate the information source, as it is unknown at the time when an information request is issued. Once the source is located, information needs to be transported back to the user's car. Most likely the topology of the ad-hoc network has since changed and therefore other cars are involved in the return path than in the forward run. Information discovery and information retrieval are key challenges for implementation of the Pull Paradigm. In this context, the group is working on advanced algorithms for information management in vehicular ad-hoc networks.