Date Added: Mar 2011
Wireless Sensor Networks (WSNs) have moved into real-world applications, and their extension to Wireless Sensor and Actuator Networks (WSANs) is in progress. Traditional application areas for WSNs include building automation, environmental monitoring, and habitat monitoring, and one major challenge is to cope with the energy limitations of the battery-powered sensor nodes. Real-time aspects are not exhaustively considered so far, since such WSN applications hardly need real-time communication. With the introduction of WSANs, applications are emerging that would significantly benefit from the possibility of real-time communication. In the industrial sector many applications for WSANs can be found that have hard real-time requirements such as open- or closed-loop controlled systems.