22,365 research outputs found
Proposition and validation of an original MAC layer with simultaneous medium accesses for low latency wireless control/command applications
Control/command processes require a transmission system with some
characteristics like high reliability, low latency and strong guarantees on
messages delivery. Concerning wire networks, field buses technologies like FIP
offer this kind of service (periodic tasks, real time constraints...).
Unfortunately, few wireless technologies can propose a communication system
which respects such constraints. Indeed, wireless transmissions must deal with
medium characteristics which make impossible the direct translation of
mechanisms used with wire networks. The purpose of this paper is to present an
original Medium Access Control (MAC) layer for a real time Low Power-Wireless
Personal Area Network (LP-WPAN). The proposed MAC-layer has been validated by
several complementary methods; in this paper, we focus on the specific
Simultaneous Guaranteed Time Slot (SGTS) part
KRATOS: An Open Source Hardware-Software Platform for Rapid Research in LPWANs
Long-range (LoRa) radio technologies have recently gained momentum in the IoT
landscape, allowing low-power communications over distances up to several
kilometers. As a result, more and more LoRa networks are being deployed.
However, commercially available LoRa devices are expensive and propriety,
creating a barrier to entry and possibly slowing down developments and
deployments of novel applications. Using open-source hardware and software
platforms would allow more developers to test and build intelligent devices
resulting in a better overall development ecosystem, lower barriers to entry,
and rapid growth in the number of IoT applications. Toward this goal, this
paper presents the design, implementation, and evaluation of KRATOS, a low-cost
LoRa platform running ContikiOS. Both, our hardware and software designs are
released as an open- source to the research community.Comment: Accepted at WiMob 201
A Survey of Green Networking Research
Reduction of unnecessary energy consumption is becoming a major concern in
wired networking, because of the potential economical benefits and of its
expected environmental impact. These issues, usually referred to as "green
networking", relate to embedding energy-awareness in the design, in the devices
and in the protocols of networks. In this work, we first formulate a more
precise definition of the "green" attribute. We furthermore identify a few
paradigms that are the key enablers of energy-aware networking research. We
then overview the current state of the art and provide a taxonomy of the
relevant work, with a special focus on wired networking. At a high level, we
identify four branches of green networking research that stem from different
observations on the root causes of energy waste, namely (i) Adaptive Link Rate,
(ii) Interface proxying, (iii) Energy-aware infrastructures and (iv)
Energy-aware applications. In this work, we do not only explore specific
proposals pertaining to each of the above branches, but also offer a
perspective for research.Comment: Index Terms: Green Networking; Wired Networks; Adaptive Link Rate;
Interface Proxying; Energy-aware Infrastructures; Energy-aware Applications.
18 pages, 6 figures, 2 table
Vibration Alert Bracelet for Notification of the Visually and Hearing Impaired
This paper presents the prototype of an electronic vibration bracelet designed to help the visually and hearing impaired to receive and send emergency alerts. The bracelet has two basic functions. The first function is to receive a wireless signal and respond with a vibration to alert the user. The second function is implemented by pushing one button of the bracelet to send an emergency signal. We report testing on a prototype system formed by a mobile application and two bracelets. The bracelets and the application form a complete system intended to be used in retirement apartment communities. However, the system is flexible and could be expanded to add new features or to serve as a research platform for gait analysis and location services. The medical and professional potential of the proposed system is that it offers a simple, modular, and cost-effective alternative to all the existing medical devices with similar functionality currently on the market. The proposed system has an educational potential as well: it can be used as a starting point for capstone projects and demonstration purposes in schools to attract students to STEM disciplines
Panda: Neighbor Discovery on a Power Harvesting Budget
Object tracking applications are gaining popularity and will soon utilize
Energy Harvesting (EH) low-power nodes that will consume power mostly for
Neighbor Discovery (ND) (i.e., identifying nodes within communication range).
Although ND protocols were developed for sensor networks, the challenges posed
by emerging EH low-power transceivers were not addressed. Therefore, we design
an ND protocol tailored for the characteristics of a representative EH
prototype: the TI eZ430-RF2500-SEH. We present a generalized model of ND
accounting for unique prototype characteristics (i.e., energy costs for
transmission/reception, and transceiver state switching times/costs). Then, we
present the Power Aware Neighbor Discovery Asynchronously (Panda) protocol in
which nodes transition between the sleep, receive, and transmit states. We
analyze \name and select its parameters to maximize the ND rate subject to a
homogeneous power budget. We also present Panda-D, designed for non-homogeneous
EH nodes. We perform extensive testbed evaluations using the prototypes and
study various design tradeoffs. We demonstrate a small difference (less then
2%) between experimental and analytical results, thereby confirming the
modeling assumptions. Moreover, we show that Panda improves the ND rate by up
to 3x compared to related protocols. Finally, we show that Panda-D operates
well under non-homogeneous power harvesting
Embedded Sensor System for Early Pathology Detection in Building Construction
Structure pathology detection is an important security task in building construction, which is performed by an operator by looking manually for damages on the materials. This activity could be dangerous if the structure is hidden or difficult to reach. On the other hand, embedded devices and wireless sensor networks (WSN) are becoming popular and cheap, enabling the design of an alternative pathology detection system to monitor structures based on these technologies. This article introduces a ZigBee WSN system, intending to be autonomous, easy to use and with low power consumption. Its functional parts are fully discussed with diagrams, as well as the protocol used to collect samples from sensor nodes. Finally, several tests focused on range and power consumption of our prototype are shown, analysing whether the results obtained were as expected or not
An Energy Aware and Secure MAC Protocol for Tackling Denial of Sleep Attacks in Wireless Sensor Networks
Wireless sensor networks which form part of the core for the Internet of Things consist of resource constrained sensors that are usually powered by batteries. Therefore, careful
energy awareness is essential when working with these devices.
Indeed,the introduction of security techniques such as authentication and encryption, to ensure confidentiality and integrity of data, can place higher energy load on the sensors. However, the absence of security protection c ould give room for energy drain attacks such as denial of sleep attacks which have a higher negative impact on the life span ( of the sensors than the presence of security features.
This thesis, therefore, focuses on tackling denial of sleep attacks from two perspectives A security perspective and an energy efficiency perspective. The security perspective involves evaluating and ranking a number of security based techniques to curbing denial of sleep attacks. The energy efficiency perspective, on the other hand, involves exploring duty cycling and simulating three Media Access Control ( protocols Sensor MAC, Timeout MAC andTunableMAC under different network sizes and measuring different parameters such as the Received Signal Strength RSSI) and Link Quality Indicator ( Transmit power, throughput and energy efficiency Duty cycling happens to be one of the major techniques for conserving energy in wireless sensor networks and this research aims to answer questions with regards to the effect of duty cycles on the energy efficiency as well as the throughput of three duty cycle protocols Sensor MAC ( Timeout MAC ( and TunableMAC in addition to creating a novel MAC protocol that is also more resilient to denial of sleep a ttacks than existing protocols.
The main contributions to knowledge from this thesis are the developed framework used for evaluation of existing denial of sleep attack solutions and the algorithms which fuel the other contribution to knowledge a newly developed protocol tested on the Castalia Simulator on the OMNET++ platform. The new protocol has been compared with existing protocols and
has been found to have significant improvement in energy efficiency and also better resilience to denial of sleep at tacks Part of this research has been published Two conference
publications in IEEE Explore and one workshop paper
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