[30].
Reprogrammability of Sensor Nodes
In query-based sensor networks, the sensor nodes can be activated or deactivated
selectively by the messages from the sink. Besides this, the functioning
of the sensor nodes such as frequency of data updates, type of data updates,
criteria for sending data updates are to be controlled by the sink. Hence it is
required that most of the hardware settings of the sensor nodes be controllable
through the software.
5.4 Tracking-based Applications
Tracking-based WSN applications are interested in detecting, localizing and
tracking targets, and conveying the relevant information to the sink, in a
timely fashion. They combine some of the characteristics of the three application
classes discussed earlier, and consequently some of the problems for
19 Chapter 1 Design of Large-scale Sensor Networks
Aravind Iyer et al.
tracking-based applications are similar to the ones discussed earlier. For example,
when the target is detected the sensors need to promptly route its
location estimates to the sink, while minimizing the routing overheads. Also,
the sink may be interested in querying the sensors for their location estimates
of the target, so that it can compute the trajectory of the target. Following
are some of the important problems faced by tracking-based applications:
Target Detection and Classification
This is actually an application-level problem. However, it is important to
understand the mechanism of target detection and classification, in order to
better design communication protocols for such applications.
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