Quality-of-service in wireless sensor networks: state-of-the-art and future directions

Wireless sensor networks (WSNs) are one of today’s most prominent instantiationsof the ubiquituous computing paradigm. In order to achieve highlevels of integration, WSNs need to be conceived considering requirementsbeyond the mere system’s functionality. While Quality-of-Service (QoS) istraditionally associated with bit/data rate, network throughput, message delayand bit/packet error rate, we believe that this concept is too strict, inthe sense that these properties alone do not reflect the overall quality-ofserviceprovided to the user/application. Other non-functional propertiessuch as scalability, security or energy sustainability must also be consideredin the system design. This paper identifies the most important non-functionalproperties that affect the overall quality of the service provided to the users,outlining their relevance, state-of-the-art and future research directions.