Introduction: Bird’s-Eye View of Wireless Sensor Networks - Application and Multidisciplinary Aspects of Wireless Sensor Networks - page 3

Local Analysis and
Processing

Local Analysis and
Processing

Sink

Gateway

Sensors

Data Monitoring on
the Internet

Fig. 1.3 A typical sensor network usage scenario

• High price tag of communication - The amount of energy sensor nodes use for

communication is much higher than the amount they use for sensing and
computation. This means that techniques such as data compression and aggregation
are very important in sensor networks, and special routing techniques are necessary
to avoid placing too much of a routing burden on any single node in the network.
Ad hoc nature of sensor networks - Eventually, some nodes will run out of energy •

and fall out of the network. The network must be made resilient to such events,
through bypassing dead nodes in the routing process. Similarly, if more nodes
are added to replenish the sensor network, they must be seamlessly integrated
without the need for operator intervention. These considerations firmly place
sensor networks in the wider context of ad hoc computer networks.

1.2 Applications of Sensor Networks

Sensor networks began their life as a DARPA project, which materialized in the form
of IUSS (Integrated Undersea Surveillance System) later deployed by US Navy in
submarine warfare (detection of hostile submarines) [ 2 ]. Today, sensor networks
have found applications in many diverse fields such as
Military applications - terrain scanning, imaging, surveillance •

• Medicine - remote monitoring of patients, especially the elderly; skin implants for

early detection of various illnesses and measurement of blood parameters, wearable
computing, swallowable capsules for video imaging of the inside of patient's body