Many-to-Many Aggregation for Sensor Networks

Wireless sensor networks have enormous potential to aid data collection in a number of areas, such as environmental and wildlife research. In this paper, we address the challenges of supporting many-to-many aggregation in a sensor network. An application of many-to-many aggregation is in-network control of sensors. For expensive sensing tasks such as sap flux measurements and camera repositioning, we use low-cost information obtained at multiple other nodes in the network to control such tasks, e.g., decreasing sampling rates when readings are predictable or unimportant, while increasing sampling rates when there are interesting activities. In general, there is a many-to-many relationship between sources (nodes providing control inputs) and destinations (nodes requiring control outputs). We present a method for implementing many-to-many aggregation in a sensor network that minimizes the communication cost by optimally balancing a combination of multicast and in-network aggregation. Our optimization technique is efficient in finding the initial solution and handling dynamic updates.