Algorithms and applications for low power wireless sensor networks using wake up receivers Abstract: Energy is the driving problem of wireless sensor networks (WSNs). Usually sensor nodes operate for a long period of time and the only source of power supply is battery cells. The diﬃculty of accessing and exchanging the batteries leads to a desire for maintenance free sensor nodes. The functionality of WSNs can be extended through the use of low power microprocessors sensors and radio transceivers. The availability of low power hardware components provides a technological break through for wake up receivers. These receivers interact only when a special wake up signal addresses them. When a wake up signal is received the wake up receiver triggers the sensor node to activate its radio transceiver. Each sensor node has the capability of transmitting a wake up signal to a near by sensor node. Data communication occurs only when the node switches on its transceiver. During this time the rest of the nodes remain in a sleep state to sustain their energy supply. Here the nodes avoid overhearing the exchange of data packets which are not intended to them. On the contrary the duty cycle process of waking up periodically to check the medium for messages or synchronizing with other sensor nodes is not necessary. This raises the hope that duty cycling might soon be replaced by the wake up receivers. Nevertheless the wake up receivers have to resolve several challenges to be able to participate eﬃciently in sensor networks. The high energy demand of wake up signals and the short wake up coverage ranges compared to data communication diminish the capabilities of sensor nodes. Therefore in this work new wake up algorithms are developed to address the shortcoming in the technology to overcome the challenges imposed on the networks through empowering the nodes with the ability to identify eﬃcient ways to manage their energy resources. Still these shortcomings have a direct eﬀect on the ability of the network to maintain its connectivity. In general the nodes can construct a wake up network and a data communication network depending on the nodes coverage ranges. A node failure in the wake up network might disconnect the node from delivering the data to their neighbors in the data network because of the inability of the nodes to wake them up. Hybrid algorithms that combine duty cycle and wake up receivers will solve this problem through maintaining active backbones to allow the sensor network to remain connected. Moreover wake up receivers have an ...