115 research outputs found
Deployment of Optimized Algorithm for MPEG-4 Data Over Wireless Multimedia Sensor Network
Typical Wireless Sensor Network (WSN) always deals with scalar data such as temperature. These types of data
are suitable for low rate networking technology such as IEEE802.15.4. Transmitting a video for IEEE 802.15.4 raised other challenges for bandwidth limited sensor networks like WSN. The optimization method able to determine the optimal limit for quantization scale, group of picture and frame per second in order to suit the WSN environment. Changing these parameters affects the bandwidth requirement and video quality in term of Peak Signal to Noise Ratio (PSNR). This project aims to create an embedded code in TelG mote according to this concept. Results from experiment show improvements in packet delivery ratio of 28% for Akiyo qcif file, 27% for Foreman qcif file and 9% for Mobile qcif file. This work proved that the method has successfully increased the network performance
Cross-Layer measurement on an IEEE 802.11g wireless network supporting MPEG-2 video streaming applications in the presence of interference
The performance of wireless local area networks supporting video streaming applications, based on MPEG-2 video codec, in the presence of interference is here dealt with. IEEE 802.11g standard wireless networks, that do not support QoS in according with IEEE 802.11e standard, are, in particular, accounted for and Bluetooth signals, additive white Gaussian noise, and competitive data traffic are considered as sources of interference. The goal is twofold: from one side, experimentally assessing and correlating the values that some performance metrics assume at the same time at different layers of an IEEE 802.11g WLAN delivering video streaming in the presence of in-channel interference; from the other side, deducing helpful and practical hints for designers and technicians, in order to efficiently assess and enhance the performance of an IEEE 802.11g WLAN supporting video streaming in some suitable setup conditions and in the presence of interference. To this purpose, an experimental analysis is planned following a cross-layer measurement approach, and a proper testbed within a semianechoic chamber is used. Valuable results are obtained in terms of signal-to-interference ratio, packet loss ratio, jitter, video quality, and interference data rate; helpful hints for designers and technicians are finally gained
Reliable multimedia transmission over wireless sensor network
Nowadays, video streaming application is widely used in wired as well as wireless environment. Extending this application into Wireless Sensor Networks (WSN) for IEEE 802.15.4 network has attracted lots of attention in the research community. Reliable data transmission is one of the most important requirements in WSN especially for multimedia application. Moreover, multimedia application requires high bandwidth and consumes large memory size in order to send video data that requires small end-to-end (ETE) delay. To overcome this problem, rate control serves as an important technique to control the bit rate of encoded video for transmission over a channel of limited bandwidth and low data rate which is 250kbps with small Maximum Transmission Unit (MTU) size of 127 bytes. Therefore, a rate control model called enhanced Video Motion Classification based (e-ViMoC) model using an optimal combination of parameter setting is proposed in this thesis. Another challenging task to maintain the video quality is the design of an enhanced transport protocol. Standard transport protocols cannot be directly applied in WSN specifically, but some modifications are required. Therefore, to achieve high reliability of video transmission, the advantages of User Datagram Protocol (UDP) features are applied to the proposed transport protocol called Lightweight Reliable Transport Protocol (LRTP) to tailor to the low data rate requirement of WSN. Besides, priority queue scheme is adopted to reduce the end-to-end delay while maintaining the reliability and energy efficiency. Evalvid simulation tool and exhaustive search method are used to determine optimal combination of quantization scale (q), frame rate (r) and Group of Picture (GOP) size (l) values to control the bit rate at the video encoder. The model of e-ViMoC is verified both with simulation and experimental work. The proposed transport protocol has been successfully studied and verified through simulation using Network Simulator 2 (NS-2). From the simulation results, the proposed e-ViMoC encoded video enhances the Packet Delivery Ratio (PDR) by 5.14%, reduces the energy consumed by 16.37%, improves the Peak Signal to Noise Ratio (PSNR) by 4.37% and reduces the ETE delay by 23.69% in average, compared to non-optimized encoded video. The tested experiment experiences slightly different result where the PDR is 6% lower than simulation results. Meanwhile, the combination of e-ViMoC and LRTP outperforms the standard transport protocol by average improvement of 142.9% for PDR, average reduction of 8.87% for energy consumption, average improvement of 4.1% for PSNR, and average reduction of 19.38% for ETE delay. Thus, the simulation results show that the combination of proposed e-ViMoC and LRTP provides better reliability performance in terms of the PDR while simultaneously improves the energy efficiency, the video quality and ETE delay
Test and evaluation of a prototyped sensor-camera network for persistent intelligence, surveillance, and reconnaissance in support of tactical coalition networking environments
This thesis investigated the feasibility of deploying an integrated sensor-camera network in military and law enforcement applications. The system was built using entirely commercial-off-the-shelf technologies. The prototype used the unattended ground sensors combined with digital video surveillance cameras to provide accurate real-time situational awareness, persistent intelligence and remote security. A robust testing and evaluation plan was created to measure the system's performance based on specific metrics. The tests focused primarily on the capabilities of the sensor aspect of the network. Tests were conducted to determine the maximum detection range, probabilities of detection, maximum communications range, and battery life. Mathematical models were created to assist network planners. Additionally, the prototyped system was tested through field exercises as part of the Naval Postgraduate School's Coalition Operating Area Surveillance and Targeting System field demonstrations in California and northern Thailand. Although the sensing capabilities exceeded the minimum metrics, the system was not suitable for use in military applications. However, the prototyped network would work well in less demanding law enforcement environments. Additionally, the feasibility and the need to develop an integrated sensor-camera network were demonstrated.http://archive.org/details/testndevaluation109452780US Navy (USN) author.Approved for public release; distribution is unlimited
On the synchronization of IEEE 802.15.5 wireless mesh sensor networks: Shortcomings and improvements
Flexi-WVSNP-DASH: A Wireless Video Sensor Network Platform for the Internet of Things
abstract: Video capture, storage, and distribution in wireless video sensor networks
(WVSNs) critically depends on the resources of the nodes forming the sensor
networks. In the era of big data, Internet of Things (IoT), and distributed
demand and solutions, there is a need for multi-dimensional data to be part of
the Sensor Network data that is easily accessible and consumable by humanity as
well as machinery. Images and video are expected to become as ubiquitous as is
the scalar data in traditional sensor networks. The inception of video-streaming
over the Internet, heralded a relentless research for effective ways of
distributing video in a scalable and cost effective way. There has been novel
implementation attempts across several network layers. Due to the inherent
complications of backward compatibility and need for standardization across
network layers, there has been a refocused attention to address most of the
video distribution over the application layer. As a result, a few video
streaming solutions over the Hypertext Transfer Protocol (HTTP) have been
proposed. Most notable are Apple’s HTTP Live Streaming (HLS) and the Motion
Picture Experts Groups Dynamic Adaptive Streaming over HTTP (MPEG-DASH). These
frameworks, do not address the typical and future WVSN use cases. A highly
flexible Wireless Video Sensor Network Platform and compatible DASH (WVSNP-DASH)
are introduced. The platform's goal is to usher video as a data element that
can be integrated into traditional and non-Internet networks. A low cost,
scalable node is built from the ground up to be fully compatible with the
Internet of Things Machine to Machine (M2M) concept, as well as the ability to
be easily re-targeted to new applications in a short time. Flexi-WVSNP design
includes a multi-radio node, a middle-ware for sensor operation and
communication, a cross platform client facing data retriever/player framework,
scalable security as well as a cohesive but decoupled hardware and software
design.Dissertation/ThesisDoctoral Dissertation Electrical Engineering 201
Wireless Sensor Networks
The aim of this book is to present few important issues of WSNs, from the application, design and technology points of view. The book highlights power efficient design issues related to wireless sensor networks, the existing WSN applications, and discusses the research efforts being undertaken in this field which put the reader in good pace to be able to understand more advanced research and make a contribution in this field for themselves. It is believed that this book serves as a comprehensive reference for graduate and undergraduate senior students who seek to learn latest development in wireless sensor networks
Actas da 10ÂŞ ConferĂŞncia sobre Redes de Computadores
Universidade do MinhoCCTCCentro AlgoritmiCisco SystemsIEEE Portugal Sectio
State-of-the-Art Sensors Technology in Spain 2015: Volume 1
This book provides a comprehensive overview of state-of-the-art sensors technology in specific leading areas. Industrial researchers, engineers and professionals can find information on the most advanced technologies and developments, together with data processing. Further research covers specific devices and technologies that capture and distribute data to be processed by applying dedicated techniques or procedures, which is where sensors play the most important role. The book provides insights and solutions for different problems covering a broad spectrum of possibilities, thanks to a set of applications and solutions based on sensory technologies. Topics include: • Signal analysis for spectral power • 3D precise measurements • Electromagnetic propagation • Drugs detection • e-health environments based on social sensor networks • Robots in wireless environments, navigation, teleoperation, object grasping, demining • Wireless sensor networks • Industrial IoT • Insights in smart cities • Voice recognition • FPGA interfaces • Flight mill device for measurements on insects • Optical systems: UV, LEDs, lasers, fiber optics • Machine vision • Power dissipation • Liquid level in fuel tanks • Parabolic solar tracker • Force sensors • Control for a twin roto
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Performance enhancements for single hop and multi-hop meshed high data rate wireless personal area networks
This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.The High Data Rate (HDR) Wireless Personal Area Networks (WPANs) typically have a limited operating range and are intended to support demanding multi-media applications at high data rates. In order to extend the communication range, HDR WPANs can operate in a wireless mesh configuration (i.e. enable multiple WPAN clusters) to communicate in a multi-hop fashion. HDR WPANs face several research challenges and some of the open key issues are limited capacity, optimum resource allocation to requesting devices and maintaining Quality of Service (QoS) for real time multimedia flows. Although, there have been some scheduling algorithms proposed for HDR WPANs, the main objective is to maintain the QoS in most cases whereas efficient and fair utilization of network capacity is still largely open for research. This thesis mainly intends to resolve the issues related to capacity of HDR WPANs such as admission control, fair allocation of Channel Time Allocations (CTAs), improvement in capacity through transmission power control, and efficient utilization of time by each flow. A technique which re-orders the time slots to reduce queuing delay for meshed WPANs is also proposed and evaluated.
The first contribution aims to improve peer-to-peer connectivity in case of two or more independent piconet devices by proposing an inter-PAN communication framework that is augmented by an admission control strategy to handle the cases when the superframe capacity is congested. The queued devices are prioritized by proposing a parameter called the Rejection Ratio. The second contribution consists of a resource allocation framework for meshed WPANs. The main objectives are to reduce the control traffic due to high volume of channel time reservation requests and introduce an element of fairness in the channel time allocated to requesting devices. The objectives are achieved by using traffic prediction techniques and an estimated backoff procedure to reduce control traffic, and define different policies based on offered traffic for fair allocation of channel time. The centralized scheme uses traffic prediction techniques to use the proposed concept of bulk reservations. Based on the bulk reservations and resource allocation policies, the overall overhead is reduced while an element of fairness is shown to be maintained for certain scenarios. In the third contribution, the concepts of Time Efficiency and CTA switching are introduced to improve communication efficiency and utilization of superframe capacity in meshed WPANs. Two metrics known as Switched Time Slot (STS) and Switched Time Slot with Re-ordering (STS-R) are proposed which aim to achieve the purpose. The final contribution proposes and evaluates a technique called CTA overlappnig to improve capacity in single hop and meshed WPANs using tramission power control. Extensive simulation studies are performed to analyze and to evaluate the proposed techniques. Simulation results demonstrate significant improvements in meshed WPANs performance in terms of capacity utilization, improvement in fairness index for CTA allocation by upto 62% in some cases, reduction in control traffic overhead by upto 70% and reduction in delay for real time flows by more than 10% in some cases
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