Preprocessing in a Tiered Sensor Network for Habitat Monitoring

Abstract

We investigate task decomposition and collaboration in a two-tiered sensor network for habitat monitoring. The system recognizes and localizes a specified type of birdcalls. The system has a few powerful macronodes in the first tier, and many less powerful micronodes in the second tier. Each macronode combines data collected by multiple micronodes for target classification and localization. We describe two types of lightweight preprocessing which significantly reduce data transmission from micronodes to macronodes. Micronodes classify events according to their cross-zero rates and discard irrelevant events. Data about events of interest is reduced and compressed before being transmitted to macronodes for target localization. Preliminary experiments illustrate the effectiveness of event filtering and data reduction at micronodes

Aggregate Threshold Queries in Sensor Networks

“…all the sensors in the network are identical), in practice most real world deployments of sensor networks are tiered. Examples include [6,10,17]. Previous studies of tiered sensor networks include [16,3,8,14,18].…”

“…Many deployments of sensor networks are tiered, i.e., the network consists of two types of units: many inexpensive wireless sensing devices, referred to as motes, and fewer, more powerful control units, referred to as macro-nodes [6,10,17]. Motes are simple wireless units, typically based on simple 8-bit processors, and are very limited in their processing, memory, and energy resources.…”

Prototyping Wireless Sensor Network Applications with BTnodes

“…However, many research projects came to the conclusion that the computing and memory resources of sensor nodes are often too limited to perform typical signal processing tasks (e.g., FFT, signal correlation). Hence, clustered architectures were suggested [13,27], where the cluster-heads are equipped with more computing and memory resources. Cluster-heads then process and aggregate sensor data collected from the nodes in their cluster.…”

“…Cluster-heads then process and aggregate sensor data collected from the nodes in their cluster. In [13,27], for example, PDAs with proprietary hardware extensions for wirelessly interfacing the sensor nodes are used for this purpose. With Bluetooth-enabled sensor nodes, off-the-shelf PDAs and laptops can be easily integrated as cluster heads without hardware modification.…”

Optimizing a class of in-network processing applications in networked sensor systems

“…These include the monitoring of habitats for specific birds and animals [1], detection of intrusion [2], and target tracking/identification [3], etc. All these applications require processing of the raw data collected by the sensors.…”