1. Field of the Invention
The present invention relates to the field of remote sensing and more particularly to information processing in a wireless sensor network.
2. Description of the Related Art
Remote sensing refers to the acquisition of information of an object or phenomenon, by the use of either recording or real-time sensing device that is either wireless or not in physical or intimate contact with the object. In practice, remote sensing provides for the stand-off collection of data through the use of a variety of devices for gathering information on a given object or area. There are two main types of remote sensing: passive remote sensing and active remote sensing. In passive remote sensing, passive sensors detect natural radiation emitted or reflected by the target object or surrounding area. Active remote sensing, by comparison, utilizes active sensors that emit energy in order to scan objects and areas whereupon the sensors then detect and measure the reflected or backscattered radiation from the target.
A wireless sensor network (WSN) is a physical embodiment of a remote sensing system. A WSN primarily includes a selection of spatially distributed autonomous sensors cooperatively monitoring physical or environmental conditions, such as temperature, sound, vibration, pressure, motion or pollutants. In addition to one or more sensors, each node in a WSN is typically equipped with a radio transceiver or other wireless communications device, a microcontroller, and a power source, usually a battery. Of note, a WSN normally constitutes a wireless ad-hoc network, meaning that each sensor supports a multi-hop routing algorithm where nodes function as forwarders, relaying data packets to a base station.
To the extent that each node in a WSN can act as a transmission relay for other nodes transmitting data to a base station or other aggregation point for collected data, those nodes acting as a transmission relay can access the content of the data routed from acquiring node to aggregation point. Further, different nodes outside of the path of relay for data, but within transmission proximity to nodes in the path of relay can detect the data as the data traverses the path of relay. However, at present no additional processing is performed on data overheard in a proximate node within a path of relay from point of origin to aggregation point. Depending upon the remote sensing application, however, data overheard by nodes outside the path of relay to the aggregation point could provide additional context for relayed data. In this regard, in many cases, data overheard by nodes could be useful in enhancing the meaning of relayed data.