Efficient Broadcasts in Sensor Networks

Group Members

Sanjeev Kohli (sanjeev@eecs), Vinay Krishnan (vkris@eecs), Cheng Tien Ee (ct-ee@eecs)

Outline

To determine and minimize the set of nodes needed to broadcast a message in a sensor network.

Background

In a sensor network, queries are often sent to all motes in the network via a flooding mechanism, i.e. each mote broadcasts the query upon hearing it from its parent mote. It can easily be seen that for the query to reach all motes, not every mote has to broadcast. This is especially critical in these small devices since they have limited power. Thus, it is often desirable to incorporate some form of load balancing ability in the motes.

Various real-world considerations must be taken into account. These include fluctuating signal strengths, which result in uncertainty in the reliability of links. Also, interference when two motes transmit simultaneously in an overlapping region complicates the broadcasting of queries. These considerations make it necessary to model the physical link layer well if the scheme proposed is to have any real use.

Since the individual motes' resources are severely constrained, any scheme should preferably be deployed in a distributed manner. By making use of locally available information, each mote individually makes the decision as to whether a broadcast is needed. Hopefully, the performance of the network as a whole approaches optimality.

Approach

Literature research on wireless networks, sensor networks
Analysis of the problem for NP-completeness
Model and simulate physical link layer of sensor network
Propose and simulate distributed algorithms that solves the problem
Extend scheme to allow load balancing amongst motes

Downloadables

Simulation program: UC Berkeley's Ptolemy

Report [pdf, ps]

Related Work

Deepak Ganesan, Bhaskar Krishnamachari, Alec Woo, David Culler, Deborah Estrin and Stephan Wicker, Complex Behavior at Scale: An Experimental Study of Low-Power Wireless Sensor Networks, July 2002
Ya Xu, Solomon Bien, Yutaka Mori, John Heidemann, Deborah Estrin, Topology Control Protocols to Conserve Energy in Wireless Ad Hoc Networks, January 2003
Samuel Madden, Robert Szewczyk, Michael J. Franklin and David Culler, Supporting Aggregate Queries Over Ad-Hoc Wireless Sensor Networks
John Sucec and Ivan Marsic, Clustering Overhead for Hierarchical Routing in Mobile Ad hoc Networks
Taek Jin Kwon and Mario Geria, Efficient Flooding with Passive Clustering (PC) in Ad Hoc Networks
Yunjung Yi, Mario Gerla and Taek Jin Kwon, Efficient Flooding in Ad hoc Networks using On-Demand (Passive) Cluster Formation
Yunjung Yi, Mario Gerla Scalable AODV with Efficient Flooding based on On-Demand Clustering

Last updated: 14th May 2003