ABSTRACT
Recent advances in nano-technology make it technologically feasible and economically viable to develop low-power, battery-operated devices that integrate general-purpose computing with multiple sensing and wireless communications capabilities. It is expected that these small devices, referred to as sensor nodes,
will be mass-produced, making production costs negligible. Individual sensor nodes have a nonrenewable power supply and, once deployed, must work unattended. For most applications, we envision a massive random deployment of sensor nodes, numbering in the thousands or tens of thousands. Aggregating sensor nodes into sophisticated computation and communication infrastructures, called sensor networks, will have a significant impact on a wide array of applications, including military, scientific, industrial, health, and domestic, as illustrated in Figure 33.1. The fundamental goal of a wireless sensor network is to produce, over an extended period of time, meaningful global information from local data obtained by individual sensor nodes.1,4,9,11,21
It is expected that networking unattended wireless sensors will have a significant impact on the efficiency of many military and civil applications, such as combat field surveillance, intrusion detection, and disaster management. Wireless sensor networks process data gathered by multiple sensors to monitor events in an area of interest. For example, in a disaster management scenario, a large number of sensors can be dropped from a helicopter. Networking these sensors can assist rescue operations by locating survivors, identifying risky areas, and making the rescue crew aware of the overall situation. On the military side, the use of wireless sensor networks can limit the need for personnel involvement in the usually dangerous reconnaissance missions. Homeland security applications — including law enforcement, remote reconnaissance, monitoring, surveillance, and security zones ranging from persons to borders — can benefit enormously from the use of an underlying wireless sensor network. Similarly, medical, biological, scientific, and industrial applications can exploit wireless sensor networks to complement traditional data gathering, data fusion, and pattern matching capabilities. Wireless sensor networks also are key to the emerging “smart spaces,” which will include numerous sensor nodes interacting with the physical world to provide information services almost everywhere and at all times.14,27
However, a wireless sensor network is only as good as the information it produces. In this respect, perhaps the most important concern is information security. Indeed, in most application domains, sensor networks will constitute an information source that is a mission-critical system component and thus require commensurate security protection. Security must be provided although sensor nodes are unattended and vulnerable to tampering.5
