Introduction

Predicted by Business Week as one of the 21^st most important new technologies for the 21^st century, distributed sensor network (DSN) technology is stepping out of its cradle of laboratories and research papers, finding more and more applications, and exploring its way to success. The road map for DSNs is becoming clearer and clearer.

Powered by advances in miniaturization of microelectronic and mechanical structure (MEMS), a DSN is composed of many tiny sensor nodes, all of which have capabilities of sensing, computing, and communication. Sensor nodes have properties such as low cost, low power, and small size and have an untethered and unattended nature after deployment. Computing, data processing, communications, and system command and control is usually wireless.

Usually, a sensor node has a communication range of less than 100ft. Sensor nodes can be deployed on the ground, in the soil, under water, in the air, in vehicles, or inside buildings. Originally the topic of longtime DARPA projects, DSNs first found uses in the military arena. Today, military applications still play an important role in DSN development and many other applications have been tried and validated. DSNs can be used for threat alerting, military sensing, physical security, targeting, tracking, classification or identification, traffic control, video surveillance, automation, distributed robotics, and environment monitoring. Recent projects at the University of California, Los Angeles and Princeton University track woodpeckers and zebras, respectively, in the wild. There is also a consortium of universities in Louisiana that use sensor networks to monitor oil drilling platforms in the gulf of Mexico to help safeguard environmentally sensitive regions.

Sensor networks are an example of a ubiquitous or ambient technology. Systems interact directly with their environment, instead of only interacting with human users. It is possible that the recent explosion of interest in sensor networks is mainly due to their embodiment of this new mindset. It has long been noted that the desktop computer market is nearly saturated. If technology is to expand, it will have to become more independent of its human parents. Challenges in DSN technology include deployment, network discovery, routing, collaborative data processing, geographical reorganization and localization, self-organized control, energy awareness, performance evaluation, and network security.

This journal will cover many active areas and topics in DSN research, from purely pragmatic issues to purely theoretical issues and from deployment to application and evaluation. We will also present regular reviews of relevant literature, books, and emerging technologies.