Efficient traffic and resource control approaches to mitigate the effects of congestion in wireless sensor networks

Abstract

Recent developments in Wireless Sensor Networks (WSNs) open up applications which frequently demand high traffic rate, particularly during the period of event recognition and simultaneous transmissions. Handling such huge volume of information remains a challenging issue in resource constrained networks such as WSNs, where data transmission normally involves a many-to-one communication model. This effect frequently results in situations of congestion due to steady buffer overflow, which prevents the performance of WSNs to the extreme level of collapsing the functioning of the entire network. The research work reported herein proposes different approaches to circumvent the problem of congestion and its impact in WSNs. Diverse applications of Wireless Multimedia Sensor Networks (WMSNs) from border surveillance to industrial applications concentrate on various kinds of data such as snapshot, acoustic data and video streaming. Each such kind of data has its own QoS requirements in terms of fairness, assured data rate and delivery of real-time data. In WSNs, congestion has a negative impact on application level QoS metrics. The various schemes to control and avoid congestion in WSNs can be categorized as traffic control and resource control. A detailed survey of literature shows that in traffic control, a fixed threshold is used by various approaches to perceive congestion. However, in the dynamic environment of WSNs, determining such a fixed value is highly complicated. The usage of broadcast nature of WSNs to relay feedback about congestion to neighbouring nodes is more evident whereas there is no assurance for these messages. newline