It is important for the life time of a wireless sensor network (WSN) to reduce the amount of data transferred through the network. As a typical approach, sensor data is filtered before propagating updates, to a node at the edge of a network, where it can be fused. Information Fusion inside the network can reduce the amount of data propagated, by fusing data before and in propagation, without losing the information value in it. We explore infrastructures for distributed fusion, with fusion nodes located at strategic nodes inside the network, as an approach of structured distributed fusion for WSNs. We propose an infrastructure for a white-board approach that uses a distributed real-time database with virtual full replication. With such an approach, both raw and fused data are logically available at all nodes and physically available where used, such that only used data will be propagated and use resources. The actual resource usage will be relative to the actual demand for data, rather than to the amount of data published at the white-board. We present an exploration of such an infrastructure, and points out future key research questions for such a white-board approach.