On Join Location in Sensor Networks

We consider the problem of processing join queries in a wireless sensor network, focusing on where (which sensor node(s)) to process the join. We propose four strategies for processing such queries and investigate their performance across several scenarios. Not surprisingly, our experiments show that no single strategy performs best for all scenarios. In order to avoid the potential high cost of using a fixed strategy for processing all queries, we develop a cost-based model that can be used to select the best join strategy for the query at hand. Our experiments confirm that, given a set of queries, selecting the join strategy based on the cost model is always better than using any fixed strategy for all queries.