Building Sensor Networks: From Design to Applications

Book Preface

The building of Wireless Sensor Networks (WSNs) continues to capture the imagination of a large number of researchers, scientists, and engineers as well as hobbyists and practitioners. Clearly, developing a system relying on nodes of sometimes-unremarkable capabilities is a unique challenge. In a sense, WSNs are a form of “retro” computing that strikes a nostalgic chord of “trying to do more with less” that runs against the zeitgeist of abundant computing and storage resources. The appeal of WSNs is further enhanced by a conspiracy of several interested parties that are rarely seen together. For starters, scientists find in WSNs the potential to utilize them to perform better science by deploying nodes abundantly and closer to the area of phenomena that they want to observe or control. Hobbyists and practitioners see in WSNs the potential of trying out novel ideas and practical gadgets without having to take on a mortgage to afford the necessary equipment. Computer scientists see in WSNs the embodiment of large-scale vertices-and-edges abstractions coupled with elementary computing, rekindling their interest in truly distributed computing. Electrical engineers see in WSNs the potential for a signal-processing and -control coordination platform of exceptional flexibility. The list of WSN fascination goes on and on. In other words, their attraction lies in how you build them as well as (once built) what you can do with them.

Nevertheless, stepping back and looking at the big picture, one is bound to remark that, for all the interest WSNs have created over the past decade (if not more), there are few examples to show that they are truly delivering on the promise and anticipation that has fueled their popularity as an area of study. Could it be that we are missing a key ingredient? Should we wait for a “killer app” or for the market to determine if WSNs are a “winner” technology or not? While market dynamics or a grassroots need for a particular application could determine whether WSNs enter the mainstream or die off by the wayside, it is fruitful to study the facets that drive WSN development conceptually as well as practically. This book attempts to punctuate those facets that, we believe, have been relatively underserved in the existing literature. For this reason, the chapters in this book thematically deviate from the classical viewpoint that sees WSNs as, in effect, two problems: routing and energy efficiency. While both are important considerations, we reduce the emphasis on them because routing has been studied to exhaustion, and energy efficiency has become a “reflex” consideration to the point that it has to be assumed that each and every publication written on WSNs is read from this viewpoint. Could we then move the focus tangentially, but in a revealing way, such that we could unearth the facets that, sometimes obliquely, are more important than squeezing the last nano-Joule of energy out of a node?