Supporting group communication among interacting agents in wireless sensor networks

Many applications of wireless sensor networks require collaboration among sensor nodes to achieve a common task. Moreover, this is often dynamic in nature. For instance, in multi-object tracking, sensor nodes that are tracking various moving objects must share information in order to improve the tracking quality. Thus, it is important to have a protocol that maintains group connectivity in such a setting. In this paper, we study the problem of maintaining communication paths among a group of moving agents that have interacted with one another. As its solution, we propose a data structure called the distributed collaboration graph (DCG), which is a communication graph obtained from the agent trajectories. The DCG can be constructed in a purely distributed fashion with very little cost and can be used for group discovery and for multicasting/broadcasting among agents. We also propose a distributed protocol which maintains a communication tree among the agents within the DCG while the agents are moving. This allows us to maintain group connectivity and provides the infrastructure for routing among the moving agents.