Wireless passive sensor networks: Research challenges

© 2010 by World Scientific Publishing Co. Pte. Ltd. All rights reserved. In the near future, networks of small intelligent sensor nodes will be deployed almost everywhere to monitor the environment. The primary challenge in the design of these networks is the energy constraint due to the finite-capacity of the batteries. Therefore, the vast majority of research efforts thus far have focused on the development of energy-efficient communication algorithms and computation techniques. This chapter describes the concept of Wireless Passive Sensor Networks (WPSN) which aims to eliminate the limitation on the system lifetime of sensor networks. In WPSN, power is externally supplied to the sensor network node via an external RF source. Hence, the lifetime of the system is no longer determined by the lifetime of the batteries. An alternative communication scheme, modulated backscattering, is also discussed to be utilized in WPSN. The feasibility of the proposed system is investigated along with the challenges for reliable communication and networking in WPSN.