In wireless sensor networks, nodes are required to reduce their idle listening time in order to minimize energy consumption and increase their lifetime. The idle listening time is decreased by making the nodes remain in sleep mode and wake up only when they are required to sense or transmit information about an event. This strategy requires the source node to send a wake-up signal before it transmits data to the network. This wake-up signal requires energy and the objective of this work is to lower this signal\u27s energy consumption.;In order to achieve this, this work uses Near Field Magnetic Induction Communication technology (NFMIC) that can communicate wirelessly over short distances using low power. Using this technology, the wake-up signal will be magnetic field lines rather than an RF signal. When a source node wants to wake up its neighbors, it generates magnetic field lines disseminating as bubbles. These lines resonate across the receiver coils of neighboring nodes, thus interrupting the sleeping nodes and waking them. This idea was implemented on a node using three different NFMIC systems. Each system had different combinations of TX and RX coils and communicated using different transmitted power. The most efficient setup was determined based on the wakeup energy efficiency. Finally, this work presents the effect of obstacles on NFMIC systems by testing them on one of our NFMIC systems. As a result of this test, the various obstacles were classified into three categories based on their attenuation effect
