Maintaining WSN QoS by brokering hibernation decisions through mediation

An established Intelligent Power Management (IPM) strategy for a Wireless Sensor Network (WSN) is based on the principal that redundant nodes can be hibernated to conserve their energy. Due to the hibernation, sensed data from the node will be unavailable, which essentially means that the WSN will be blind in the vicinity of the hibernating node. Numerous strategies have been proposed to maintain the the minimum resolution of sensed data required by the application. However, given the potential scale on which a Wireless Sensor Network (WSN) can be deployed, multi-hop communication will also be a pivotal component of such a system. When redundant nodes are deployed, which are hibernated opportunistically to conserve energy, it is crucial that sub-graphs of the network are not disconnected by the hibernation of a node. In order to ensure connectivity is preserved for all nodes in the area, a protocol is required that oversees routing integrity is maintained. Since this routing topology must be present at all times, this set represents the minimum number of nodes that must be active at any given time for a functioning network. No work to data has focussed on how these two distinct layers can co-operate in deciding when to hibernate a node. In this work, we propose and test a flexible mechanism where two or more protocols can determine the activity state of a node.