Fundamental issues

Nowadays, sensors exist everywhere. They are used for monitoring battlefield, controlling traffic, watching environment, managing manufacture process, detecting disasters, examining human’s bodies, and collecting data from hostile area, etc. In many applications, the coverage is a fundamental requirement and hence becomes an important issue in study of sensor systems, especially wireless sensor networks. For example, when a request comes to ask for information on enemy’s activities in a certain area of battlefield, a set of sensors are required to activate for covering (sensing) the target area.