Date Added: Nov 2009
Wireless Sensor Networks (WSNs) are one of today's most prominent instantiations of the ubiquituous computing paradigm. In order to achieve highlevels of integration, WSNs need to be conceived considering requirements beyond the mere system's functionality. While Quality-of-Service (QoS) is traditionally associated with bit/data rate, network throughput, message delay and bit/packet error rate, the authors believe that this concept is too strict, in the sense that these properties alone do not reflect the overall quality-of-service provided to the user/application. Other non-functional properties such as scalability, security or energy sustainability must also be considered in the system design.