On Multi-Path Aggregation of Duplicate-Sensitive Functions
Previous decades brought about a revolution in radioand microprocessor technology that made possible a plethoraof new applications. In particular, the possibility of using many inexpensive sensor nodes interconnected by wireless networks (WSN) for a number of ends, such as pollution monitoring and defense, draw the attention of the research community.WSN are usually heavily resource-constrained. Of particularrelevance is energy, since in many applications nodes shouldoperate during long periods from batteries. The literature onthis topic reveals many techniques to improve energy efficiency, one of them being the use of network aggregation. However, the problem of aggregation of duplicate sensitive summaries (e.g. sum, average, histogram, etc.) in multi-path routing networks isnot fully resolved. This paper addresses this problem by sending redundant aggregated information through different paths, so data can be reconstruct to obtain the exact summary, provided that there is at least one feasible path. Two algorithms are presented, one better suited for networks dominated by link errors and another suited to networks where the predominant error source is node failures. The algorithms are light during normal network operation, with the most intensive processing performed during the initialization phase. The approach presented hereinoutperform previous solutions found in the literature in two key aspects: complete topology independence and aggregation depth independence.
wireless sensor networks; aggregation; multipath; spatial query