Adaptive Fidelity Algorithms

A class of algorithms pertinent to sensor networks that we explore in this project are adaptive fidelity algorithms.  An adaptive fidelity algorithm is one where the quality (fidelity) of the answer can be traded against battery lifetime, network bandwidth, or number of active sensors. Of course, the resulting fidelity must still fall within acceptable bounds.

We apply adaptive fidelity to routing in energy-constrained, ad hoc, wireless networks. Nodes running our adaptive fidelity algorithms can trade off energy dissipation and data delivery quality according to application requirements. Our algorithms work above existing on-demand ad hoc routing protocols, such as AODV and DSR, without modification to the underlying routing protocols. Our major contributions are: algorithms that turn off the radio to reduce energy consumption with the involvement of application-level information, and the additional use of node deployment density to adaptively adjust routing fidelity to extend network lifetime. Algorithm analysis and simulation studies show that our energy-conserving algorithms can consume as little as 50% of the energy of an unmodified ad hoc routing protocol. Moreover, simulations of adaptive fidelity suggest that greater node density can be used to increase network lifetime; in one example a four-fold increase in density doubles network lifetime.

For more details, please see our publications. We plan to make simulation code for our adaptive fidelity algorithms available in  ns-2. An implementation on the PC-104 testbed is currently under way at UCLA LECS.


  Ya Xu     Email: [email protected]
  John Heidemann Email: [email protected]
  Deborah Estrin Email: [email protected]


   Adaptive Energy-Conserving Routing for Multihop Ad Hoc Networks
   Ya Xu, John Heidemann and Deborah Estrin
   Research Report 527, USC/Information Sciences Institute, October 2000.

Return to the main SCADDS page.