Motes

Introduction

Over the last year or so you may have heard about a new computing concept known as motes. This concept is also called smart dust and wireless sensing networks. It seems like just about every issue of Popular Science, Discover and Wired today contains a blurb about some new application of the mote idea. For example, the military plans to use them to gather information on battlefields, and engineers plan to mix them into concrete and use them to internally monitor the health of buildings and bridges.

There are thousands of different ways that motes might be used, and as people get familiar with the concept they come up with even more. It is a completely new paradigm for distributed sensing and it is opening up a fascinating new way to look at computers.In this article, you will have a chance to understand how motes work and see many of the possible applications of the technology.

Bluetooth Based Mesh Networks

Bluetooth was originally designed for personal area networks (PANs) that are quite different from the application that we had in mind. PANs are often simple star network topologies that consist of a sin-gle master and a number of attached slaves. A very simple example would be a BT-enabled cell phone nd wireless headset (a point to point connection consisting of a single master and single slave). A more complex network could involve a PC as the master with mouse, keyboard and printer attached as wireless slaves. Such a network is called a piconet in the BT specification.

Sensor Network Applications

Sensor networks have been applied to various research areas at a number of academic institutions. In particular, environmental monitoring has received a lot of attention with major projects at UCB, UCLA and other places. In addition, commercial pilot projects are staring to emerge as well. There are a number of start-up companies active in this space and they are providing mote hardware as well as application software and back-end infrastructure solutions. The University of California at Berkeley in conjunction with the local Intel Lab is conducting an environmental monitoring project using mote based sensor networks on Great Duck Island off the coast of Maine. This endeavor includes the deployment of tens of motes and several gateways in a fairly harsh outdoor environment.

Ad Hoc Networks

The Defense Advanced Research Projects Agency (DARPA) was among the original patrons of the mote idea. One of the initial mote ideas implemented for DARPA allows motes to sense battlefield conditions.

For example, imagine that a commander wants to be able to detect truck movement in a remote area. An airplane flies over the area and scatters thousands of motes, each one equipped with a magnetometer, a vibration sensor and a GPS receiver. The battery-operated motes are dropped at a density of one every 100 feet (30 meters) or so. Each mote wakes up, senses its position and then sends out a radio signal to find its neighbors.

Conclusion

We have described the design of a new enhanced sensor network node, called the Mote. This device provides enhanced CPU, storage and radio facilities that various sensor network application developers and implementers have been asking for.