Efficient Node and Sensed Module Management for Multisensory Wireless Sensor Networks

Abstract

In target tracking wireless sensor networks, choosing a part of sensor nodes to execute tracking tasks and letting the other nodes sleep to save energy are efficient node management strategies. However, at present more and more sensor nodes carry many different types of sensed modules, and the existing researches on node selection are mainly focused on sensor nodes with a single sensed module. Few works involved the management and selection of the sensed modules for sensor nodes which have several multi-mode sensed modules. This work proposes an efficient node and sensed module management strategy, called ENSMM, for multisensory WSNs (wireless sensor networks). ENSMM considers not only node selection, but also the selection of the sensed modules for each node, and then the power management of sensor nodes is performed according to the selection results. Moreover, a joint weighted information utility measurement is proposed to estimate the information utility of the multiple sensed modules in the different nodes. Through extensive and realistic experiments, the results show that, ENSMM outperforms the state-of-the-art approaches by decreasing the energy consumption and prolonging the network lifetime. Meanwhile, it reduces the computational complexity with guaranteeing the tracking accuracy.

An Ultra-Wide Load Range Voltage Converter Using Proactive Phase Frequency Modulation for IoT Sensors

“…In addition to its main functions, we implemented various test and fallback modes in the controller for test purposes. The next entry of the OSI table provides the state information for each capacitor bank, which is stored in VCR state registers (state_reg[0] and state_reg [1]…”

“…In addition to its main functions, we implemented various test and fallback modes in the controller for test purposes. The next entry of the OSI table provides the state information for each capacitor bank, which is stored in VCR state registers (state_reg[0] and state_reg [1] 6, which allows one, two or all four converters to operate concurrently. It is also possible to operate two or four capacitor banks in phase, by asserting sphase input, to compare the performance of single-phase and multi-phase operations.…”

“…The test controller has been synthesized using Synopsys design tools targeting 250 MHz. The state_sig [1] spi_reg [1] spi_reg The multi-phase generator (MPG) block reads the state signals and operates the capacitor banks by supplying phase-delayed signals. The four operation modes of MPG are listed in Figure 6, which allows one, two or all four converters to operate concurrently.…”

“…It reveals that the NMOS and PMOS gates have a non-overlapped period when transitioning between ϕ1 and ϕ2, which ensures that no short-circuit path occurs while switching. For the test chip, the non-overlapped period introduced by the NOSD test_mode [1] in_dig *sphase: 0-Multiphase, 1-Single phase operation *op_mode [1: Figure 8 illustrates an example of non-overlapped switching operation. Figure 8a shows example MOSFET switches corresponding to transmission gates cA0 and cB0 of Figure 7.…”

“…Modern sensor nodes perform a set of tasks repeatedly, and thus often exhibit periodic transition between different load states based on a schedule [1][2][3], as shown in Figure 1. The predictable transition schedule allows the software to proactively reconfigure the voltage converter to supply required amount of current for various load conditions.…”