In Wireless Sensor Networks (WSNs), sensor nodes have a limitation in energy capacity due to its characteristics of being battery-operated. Due to this reason, energy efficiency is regarded as the most important factor leading to the usage of duty cycling. Several synchronous and asynchronous MAC protocols have been proposed using the duty cycling concept. Among those, RMAC [4] exploits a contr...

A novel wake-up receiver for wireless sensor networks is introduced. It operates with a modified medium access protocol (MAC), allowing low-energy consumption and practical latency. The ultra-low-power wake-up receiver operates with enhanced duty-cycled listening. The analysis of energy models of the duty-cycle-based communication is presented. All the WuRx blocks are studied to obey the duty-c...

Iontophoresis (IOP) is a noninvasive method of delivering medication transcutaneously through the skin. The electrodes used in this method should tightly fit to rough and irregular surfaces and be biologically safe, easy to handle and prepare, and cost-effective. To satisfy these requirements, calcium alginate gel can be a candidate electrode for IOP. Using calcium alginate gel electrodes, we e...

This paper presents a Fast Forward MAC layer designed for hard real-time applications in wireless sensor networks. This protocol is an enhancement to the IEEE 802.15.4 standard MAC layer proposed for Low-Rate Personal Area Network. The energy conservation mechanism proposed by the current standard is quite efficient and very flexible. This flexibility comes from the ability to configure differe...

Wireless sensor networks are applied in a wide variety of applications, such as environment monitoring, target tracking and so on. Neighbour discovery process is an important component of wireless sensor network’s access and basic communication. Duty-cycle based wireless sensor networks can save energy, but challenges the process of neighbour discovery. A comparison between neighbour discovery ...

We explore the potential of the nonlinear amplifying loop mirror (NALM)-based phase-preserving 2R (reamplification and reshaping) regenerator for simultaneous regeneration of multiple wavelength-division-multiplexed (WDM) channels. While not considering nonlinear multi-channel propagation, we address two issues of the phase-preserving NALM that appear to us as the major obstacles in adopting it...

Aiming at researching the QoS performance of slotted CSMA/CA mechanism in beacon-enabled IEEE802.15.4, this paper analyzes the effect relationship between QoS and superframe parameters through analytic mathematical model and simulation method. Firstly, the nodes’ sleeping time of WSNs is deduced from duty cycle mathematical formulation. Therefore, the energy consumption directly related to slee...

A fast-locking, high-precision and low-jitter pulsewidth control loop for high-speed pipelined ADC is presented. Only through controlling the delay of rising edge to adjust duty cycle, the clock jitter could be suppressed greatly. An improved charge pump with a follower circuit and self-biased loop was designed to decrease the voltage ripples for higher accuracy and lower jitter. A start-up cir...

This paper presents considerations on the switching frequency and duty cycle & operating equations of softswitching BUCK chopper. These considerations are discussed and applied to selected soft-switching families such as ZVS-QRC, ZCS-QRC, ZVS-QSW-CV, ZCS-QSWCC, ZVT-PWM and ZCT-PWM [1]. The limitations on switching frequency and duty cycle are derived in terms of: chopper input voltage (Vg), cho...