Recognizing Moving Groups with Infrastructure Support

Detection of nearby nodes in wireless ad hoc networks requires periodic neighborhood scanning which is, in terms of energy, a rather expensive procedure: The nodes transmit the discovery packets and, furthermore, their reception circuits have to be active most of the time. Since distributed moving group detection algorithms rely on those nearby node-detection procedures, this kind of overhead seems unavoidable for them. However, in most of the scenarios some fixed infrastructure co-exist which may support the detection process. In this paper we propose a method that uses the infrastructure to gain hints about moving groups and triggers the distributed process only if there is some degree of confidence that such a group exists. This reduces the overhead of the neighborhood scans by approximately 90% translating e.g. to longer lifetime for the battery-driven nodes