Search results for " Wireless"
showing 10 items of 200 documents
Current characterisation for ultra low power wireless body area networks
2010
The emerging area of body area networks (BAN) imposes challenging requirements on hardware and software to achieve the desired lifetimes for certain devices such as long term medical implants. In this paper, we propose a novel approach to the measurement and characterisation of the energy consumption of BAN devices. The approach uses a low cost energy auditing circuit and addresses the problem of accurately measuring low-level current consumption. This new technique will allow precise and analytical measurements of systems and components in terms of energy. This will help circuit designers minimise power consumption in BAN devices. Software engineers might use this approach to validate and …
DTMC modeling for performance evaluation of DW-MAC in wireless sensor networks
2016
Synchronized duty cycling (DC) aligns sensor nodes to wake up at the same time in order to reduce idle listening for medium access control (MAC) in wireless sensor networks (WSNs). Demand wakeup MAC (DW-MAC) is a popular synchronous DC MAC protocol which allows nodes to compete and transmit multiple packets in one operational cycle. This multiple packet transmission (MPT) feature makes DW-MAC more energy efficient when comparing with other existing single time competition based protocols such as sensor MAC (S-MAC). In the literature, no analytical model exists to evaluate the performance of DW-MAC. In this paper, we develop two associated discrete time Markov chain (DTMC) models and incorpo…
SCARKER: A sensor capture resistance and key refreshing scheme for mobile WSNs
2011
How to discover a captured node and to resist node capture attack is a challenging task in Wireless Sensor Networks (WSNs). In this paper, we propose a node capture resistance and key refreshing scheme for mobile WSNs which is based on the Chinese remainder theorem. The scheme is able of providing forward secrecy, backward secrecy and collusion resistance for diminishing the effects of capture attacks. By implementing our scheme on a Sun SPOT based sensor network testbed, we demonstrate that the time for updating a new group key varies from 56 ms to 546 ms and the energy consumption is limited to 16.5–225 mJ, depending on the length of secret keys and the number of sensors in a group.
Learning from Errors: Detecting ZigBee Interference in WiFi Networks
2014
In this work we show how to detect ZigBee interference on commodity WiFi cards by monitoring the reception errors, such as synchronization errors, invalid header formats, too long frames, etc., caused by ZigBee transmissions. Indeed, in presence of non-WiFi modulated signals, the occurrence of these types of errors follows statistics that can be easily recognized. Moreover, the duration of the error bursts depends on the transmission interval of the interference source, while the error spacing depends on the receiver implementation. On the basis of these considerations, we propose the adoption of hidden Markov chains for characterizing the behavior of WiFi receivers in presence of controlle…
Analysis of the Effect of Human Presence on a Wireless Sensor Network
2011
Wireless Sensor Networks (WSNs) are gaining an increasing industry wide adoption. However, there remain major challenges such as network dimensioning and node placement especially in Built Environment Networks (BENs). Decisions on the node placement, orientation, and the number of nodes to cover the area of interest are usually ad-hoc. Ray tracing tools are traditionally employed to predict RF signal propagation; however, such tools are primarily intended for outdoor environments. RF signal propagation varies greatly indoors due to building materials and infrastructure, obstacles, node placement, antenna orientation and human presence. Because of the complexity of signal prediction, these f…
A wireless battery charger architecture for consumer electronics
2012
In this paper, an innovative design of a wireless battery charger for portable electronic devices is proposed. The wireless power transfer is implemented through the magnetic coupling between a power transmitter, which is connected to the grid, and a power receiver, which is integrated inside the load device. An innovative receiver architecture which heavily improves the power conversion efficiency is presented. The proposed solution is standard compliant and suitable for IC implementation. A comparison between a conventional and the proposed receiver architectures is carried out by SPICE simulations. As shown by simulation results, a power efficiency increase by 40% is provided by the prop…
MansOS
2010
Often software for wireless sensor networks (WSNs) is developed using a specific event based operating system (OS) such as TinyOS. However, this requires steep learning curve for the new developers. Other operating systems for embedded devices have limited support for new hardware platforms. Our goal is to provide an operating system for resource constrained devices that is easy to use for the wide range of researchers and developers familiar with C programming language and Unix operating system concepts. In addition, we provide a framework for agile portability to new hardware platforms, due to the nature of WSN systems that require specific hardware or features for the sensing tasks at ha…
Distance-related energy consumption analysis for mobile/relay stations in heterogeneous wireless networks
2010
While the availability of more than one mobile or wireless technologies is enhancing the ubiquity of the Internet access, the corresponding energy consumption effects on mobile station battery for connection selection has not been investigated in depth yet. In this paper, a heterogeneous wireless network, which consists of three constituent networks, is studied with respect to the amount of data communicated and the battery operation time. Four alternative hybrid paths for separate uplink and downlink traffic, each involving more than one network, are analyzed with respect to energy consumption aspects of the mobile (and relay) station. The energy in these paths is analyzed mainly by consid…
UAV-Assisted Data Collection in Wireless Sensor Networks: A Comprehensive Survey
2021
Wireless sensor networks (WSNs) are usually deployed to different areas of interest to sense phenomena, process sensed data, and take actions accordingly. The networks are integrated with many advanced technologies to be able to fulfill their tasks that is becoming more and more complicated. These networks tend to connect to multimedia networks and to process huge data over long distances. Due to the limited resources of static sensor nodes, WSNs need to cooperate with mobile robots such as unmanned ground vehicles (UGVs), or unmanned aerial vehicles (UAVs) in their developments. The mobile devices show their maneuverability, computational and energy-storage abilities to support WSNs in mul…
An Energy-Autonomous Wireless Sensor with Simultaneous Energy Harvesting and Ambient Light Sensing
2021
Wireless sensor nodes (WSNs) are generally powered by batteries, which results in a substantial limitation to the places where the nodes can be installed, to the maximum number of deployable devices, and to the node lifetime. To meet the demand for Internet-of-Things (IoT) applications that require a large number of maintenance-free, low cost, wireless sensor nodes, this paper proposes a wireless sensor platform with a single photovoltaic transducer that performs the dual role of harvesting energy and sensing ambient light. This dual use allows even smaller and cheaper nodes that do not require any form of supporting external power, with a reduced component count. The device implements off-…