This results in more robust network coverage with fewer black spots. With reliable radio connections, fewer packets are lost, resulting in fewer packet retransmissions and an overall more efficient system. For a radio receiver, the RF selectivity is its ability to differentiate the desired signal from unwanted signal sources transmitting in other channels.
The alternate channel is one channel more removed from the adjacent channel. The greater the rejection, the better the receiver performance in the presence of interferers. Even several MHz away, high power interferers can degrade communications and result in lost packets.
One element of achieving good blocking and selectivity figures is reducing phase noise in the RF system. Phase noise, the noise introduced by short-term phase fluctuations in a signal, can be seen as sidebands that spread out from the wanted signal in the frequency domain. This noise acts to degrade the receiver performance by affecting reciprocal mixing, as shown in Figure 1, and by raising the noise floor. In a receiver, when the wanted signal is downconverted to the intermediate frequency used for signal processing, a tail of an interferer can be mixed and cannot be subsequently filtered out.
Figure 1. Phase noise basic theory. The front-end linearity of a receiver impacts resilience to nearby high power interferers. For a measure of linearity in the receiver, we turn to the input third-order intercept IIP3. It supports standards-based protocols like IEEE The highly configurable, low intermediate frequency IF receiver supports a large range of receiver channel bandwidths from 2.
This range of receiver channel bandwidths allows the ADF to support ultranarrow-band, narrow-band, and wideband channel spacing. It is designed to provide best-in-class blocking and provides excellent sensitivity. The high performance, low power analog front end AFE , utilized by the ADF, uses high dynamic range ADCs, analog complex antialiasing filtering with QEC, and digital channel filtering to remove unwanted signals in the receive chain.
To maintain high performance receive performance across all supported signal bandwidths and frequency bands, the ADF employs a reconfigurable VLIF receiver architecture with dual-band LO paths. This allows the ADF to support a wide range of applications. Figure 2. This gives end users the confidence that they will meet regulatory requirements and removes the need for costly external components such as SAW filters. This requires 60 dB adjacent channel rejection and 84 dB selectivity.
The ADF exceeds these requirements by a significant margin. The extensive growth in the wireless communications industry over the past ten years has been accompanied by growing concern for the potential hazards of drivers using wireless communication devices from moving vehicles. Given the National Highway Tr The User Needs to be discussed in this talk includes interviews with several scientists and reviews of mission concepts for the next generation of sensors, observatories, and planetary surface missions.
These observatories, sensors are envisioned to operate in extreme environments, with advanced autonomy, whereby sometimes communication to Earth is intermittent and delayed. These sensor nodes require software defined networking capabilities in order to learn and adapt to the environment, collect science data, internetwork, and communicate. For instance, on a planetary surface, autonomous sensor nodes would create their own ad-hoc network, with some nodes handling communication capabilities between the wireless sensor networks and orbiting relay satellites. A section of this talk will cover the advances in space communication and internetworking to support future space missions.
NASA's Space Communications and Navigation SCaN program continues to evolve with the development of optical communication , a new vision of the integrated network architecture with more capabilities, and the adoption of CCSDS space internetworking protocols. Monitoring devices and systems for monitoring frequency hopping wireless communications , and related methods. Monitoring devices and systems comprise a plurality of data channel modules coupled to processing circuitry. Each data channel module of the plurality of data channel modules is configured to capture wireless communications for a selected frequency channel.
The processing circuitry is configured to receive captured wireless communications from the plurality of data channel modules and to organize received wireless communications according to at least one parameter. Related methods of monitoring wireless communications are also disclosed. Wireless communication link for capsule endoscope at MHz. Simulation of a wireless communication link for a capsule endoscopy is presented for monitoring of small intestine in humans.
The realized communication link includes the transmitting capsule antenna, the outside body receiving antenna and the model of the human body. The capsule antenna is designed for operating at the frequency band of MHz with an impedance bandwidth of 10 MHz and omnidirectional radiation pattern. The quality of the communication link is improved by using directive antenna outside body inside matching layer for electromagnetic wave tuning to the body. The outside body antenna has circular polarization that guaranteeing the communication link for different orientations of the capsule inside intestine.
It is shown that the path loss for the capsule in 60 mm from the abdomen surface varies between dB in relation to the antenna orientation. This link can establish high data rate wireless communications for capsule endoscopy. Wireless Communications. Profiles the major wireless data communications WDC systems, provides an overview of how they work, and compares their communication features. Topics addressed include the market for wireless data; applications for WDC; wireless online searching; cellular data communication ; packet radio; digital cellular; criteria for evaluating WDC systems;….
Chaos-based wireless communication resisting multipath effects. In additive white Gaussian noise channel, chaos has been shown to be the optimal coherent communication waveform in the sense of using a very simple matched filter to maximize the signal-to-noise ratio. Recently, Lyapunov exponent spectrum of the chaotic signals after being transmitted through a wireless channel has been shown to be unaltered, paving the way for wireless communication using chaos.
In wireless communication systems, inter-symbol interference caused by multipath propagation is one of the main obstacles to achieve high bit transmission rate and low bit-error rate BER. How to resist the multipath effect is a fundamental problem in a chaos-based wireless communication system CWCS.
In this paper, a CWCS is built to transmit chaotic signals generated by a hybrid dynamical system and then to filter the received signals by using the corresponding matched filter to decrease the noise effect and to detect the binary information. We find that the multipath effect can be effectively resisted by regrouping the return map of the received signal and by setting the corresponding threshold based on the available information. We show that the optimal threshold is a function of the channel parameters and of the information symbols.
Practically, the channel parameters are time-variant, and the future information symbols are unavailable. In this case, a suboptimal threshold is proposed, and the BER using the suboptimal threshold is derived analytically.
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Simulation results show that the CWCS achieves a remarkable competitive performance even under inaccurate channel parameters. Wireless communications are ubiquitous. More than million Americans had cell phones in June of and expanded access to broadband is predicted this year. Despite the plethora of users, most students and teachers do not understand "how they….
Belief Propagation for spectrum awareness within one network for the multiple channel case in a previous study  39 Figure 2. The PIs have been working closely with students to carry out all the proposed research tasks. Evaluation of communication in wireless underground sensor networks. Wireless underground sensor networks WUSN are an emerging area of research that promises to provide communication capabilities to buried sensors. In this paper, experimental measurements have been conducted with commodity sensor motes at the frequency of 2.
Experiments are run to examine the received signal strength of correctly received packets and the packet error rate for a communication link. Moreover, we also illustrate a classification for wireless underground sensor network communication. Finally, we conclude that the effects of burial depth, inter-node distance and volumetric water content of the soil on the signal strength and packet error rate in communication of WUSN.
Energy scavenging system by acoustic wave and integrated wireless communication. The purpose of the project was developing an energy-scavenging device for other bio implantable devices. Researchers and scientist have studied energy scavenging method because of the limitation of traditional power source, especially for bio-implantable devices.
In this research, piezoelectric power generator that activates by acoustic wave, or music was developed. Follow by power generator, a wireless communication also integrated with the device for monitoring the power generation. The Lead Zirconate Titanate PZT bimorph cantilever with a proof mass at the free end tip was studied to convert acoustic wave to power.
The music or acoustic wave played through a speaker to vibrate piezoelectric power generator. The LC circuit integrated with the piezoelectric material for purpose of wireless monitoring power generation. However, wireless monitoring can be used as wireless power transmission, which means the signal received via wireless communication also can be used for power for other devices. Size of 74 by 7 by 7cm device could generate and transmit mVp from 70 mm distance away with electrical resonant frequency at Underwater fiber- wireless communication with a passive front end. We propose and experimentally demonstrate a novel concept on underwater fiber- wireless Fi-Wi communication system with a fully passive wireless front end.
A low-cost step-index SI plastic optical fiber POF together with a passive collimating lens at the front end composes the underwater Fi-Wi architecture. We have achieved a 1. Although the wireless part is very short, it actually plays a crucial role in practical underwater implementation, especially in deep sea. Compared with the wired solution e. By combining high-capacity robust POF with the mobility and ubiquity of underwater wireless optical communication UWOC , the proposed underwater Fi-Wi technology will find wide application in ocean exploration.
Emissions in aircraft communication and navigation bands are measured for the latest generation of wireless phones. A base-station simulator is used to control the phones. The measurements are conducted using reverberation chambers, and the results are compared against FCC and aircraft installed equipment emission limits. The results are also compared against baseline emissions from laptop computers and personal digital assistant devices that are currently allowed to operate on aircraft.
Acemind new indoor full duplex optical wireless communication prototype. For over a century and Mr. Guglielmo Marconi invention, systems using radio waves have controlled over wireless telecommunication solutions; from Amplitude Modulation AM radio products to satellite communications for instance. But beyond an increasingly negative opinion face to radio waves and radio spectrum availability more and more reduced; there is an unprecedented opportunity with LED installation in displays and lighting to provide optical wireless communication solutions.
Pending finalization of the standard review process IEEE It offers an indoor bilateral optical wireless communication prototype having the following characteristics: use of the existing electrical infrastructure, through judicious combination with Light Fidelity LiFi , Power Line Communication PLC and Ethernet to reduce the implementation cost. Dimensionally optimized LiFi module is presented in order to offer the possibility for integration inside a laptop. After the introduction, we will present the results of a market study from Orange Labs customers about their opinion on LiFi components.
Then we will detail the LiFi prototype, from the physical layer aspect to MAC layer before concluding on commercial development prospects. Efficient data communication protocols for wireless networks. In this dissertation, efficient decentralized algorithms are investigated for cost minimization problems in wireless networks.
For wireless sensor networks, we investigate both the reduction in the energy consumption and throughput maximization problems separately using multi-hop data aggregation for correlated data in wireless sensor networks. The proposed algorithms exploit data redundancy using a game theoretic framework. For energy minimization, routes are chosen to minimize the total energy expended by the network using best response dynamics to local data. The cost function used in routing takes into account distance, interference and in-network data aggregation.
The proposed energy-efficient correlation-aware routing algorithm significantly reduces the energy consumption in the network and converges in a finite number of steps iteratively. For throughput maximization, we consider both the interference distribution across the network and correlation between forwarded data when establishing routes. Nodes along each route are chosen to minimize the interference impact in their neighborhood and to maximize the in-network data aggregation.
The resulting network topology maximizes the global network throughput and the algorithm is guaranteed to converge with a finite number of steps using best response dynamics. For multiple antenna wireless ad-hoc networks, we present distributed cooperative and regret-matching based learning schemes for joint transmit beanformer and power level selection problem for nodes operating in multi-user interference environment.
Total network transmit power is minimized while ensuring a constant received signal-to-interference and noise ratio at each receiver. In cooperative and regret-matching based power minimization algorithms, transmit beanformers are selected from a predefined codebook to minimize the total power. By selecting transmit beamformers judiciously and performing power adaptation, the cooperative algorithm is shown to.
Study and design on USB wireless laser communication system. Wireless laser communication part and USB interface circuit part are discussed in detail. We also give the periphery design of the chip ANQ, the control circuit to realize the transformation from parallel port to serial bus, and the circuit of laser sending and receiving of laser communication part, which are simply, cheap and workable. And then the four part of software are analyzed as followed.
We have debugged and consummated the 'ezload,' and the GPD of the drivers. Windows application performs functions and schedules the corresponding API functions to let the interface practical and beautiful. The system can realize USB wireless laser communication between computers, which distance is farther than 50 meters, and top speed can be bigger than 8 Mbps.
The system is of great practical sense to resolve the issues of high-speed communication among increasing districts without fiber trunk network. Resonant tunnelling diode terahertz sources for broadband wireless communications. Wasige, Edward; Alharbi, Khalid H. They are realised in various circuit topologies including those that use a single RTD device, 2 RTD devices and up to 4 RTD devices for increasingly higher output power.
The oscillators are realised using only photolithography by taking advantage of the large micron-sized but broadband RTD devices. The paper will also describe properties of RTD devices as photo-detectors which makes this a unified technology that can be integrated into both ends of a wireless link, namely consumer portable devices and fibre-optic supported base-stations since integration with laser diodes is also possible.
Department of Transportation DOT. Committee , Airport Surface Wireless Communications. Wireless networking and mobile communications is increasing around the world and in all sectors of our lives. With increasing use, the density and complexity of the systems increase with more base stations and advanced protocols to enable higher data throughputs.
The security of data transported over wireless networks must also evolve with the advances in technologies enabling more capable wireless networks. However, means for analysis of the effectiveness of security approaches and implementations used on wireless networks are lacking. More specifically a capability to analyze the lower-layer protocols i. In this research paper several emulation tools and custom extensions that enable an analysis platform to perform cyber security analysis of lower layer wireless networks is presented. A use case of a published exploit in the Short-Range Nucleon-Nucleon Correlations.
Valence-shell nucleon knock-out experiments, such as 12C e,e'p 11B, measure less strength then is predicted by independent particle shell model calculations. The theoretical solution to this problem is to include the correlations between the nucleons in the nucleus in the calculations. Motivated by these results, many electron scattering experiments have tried to directly observe these correlations in order to gain new insight into the short-range part of the nucleon-nucleon potential.
Unfortunately, many competing mechanisms can cause the same observable final-state as an initial-state correlation, making truly isolating the signal extremely challenging. Essentially two propulsion vehicles in one, the OMV could be powered by a main propulsion module , or, in its short range vehicle configuration shown here, use its own hydrazine and cold gas thrusters. As envisioned by Marshall Space Flight Center plarners, the OMV would be a remotely-controlled free-flying space tug which would place, rendezvous, dock, and retrieve orbital payloads.
Final report : mobile surveillance and wireless communication systems field operational test. Volume 1, Executive summary. This study focused on assessing the application of traffic monitoring and management systems which use transportable surveillance and ramp meter trailers, video image processors, and wireless communications. The mobile surveillance and wireless commu An m-health system for real-time wireless communication of medical video based on open-source software is presented. The objective is to deliver a low-cost telemedicine platform which will allow for reliable remote diagnosis m-health applications such as emergency incidents, mass population screening, and medical education purposes.kirtihospital.com/what-good-is-an-o-vowels.php
Radio technology ensures reliable communications
The performance of the proposed system is demonstrated using five atherosclerotic plaque ultrasound videos. The videos are encoded at the clinically acquired resolution, in addition to lower, QCIF, and CIF resolutions, at different bitrates, and four different encoding structures. Commercially available wireless local area network WLAN and 3. Objective video quality assessment is based on PSNR ratings, following calibration using the variable frame delay VFD algorithm that removes temporal mismatch between original and received videos.
Clinical evaluation is based on atherosclerotic plaque ultrasound video assessment protocol. Experimental results show that adequate diagnostic quality wireless medical video communications are realized using the designed telemedicine platform. HSPA cellular networks provide for ultrasound video transmission at the acquired resolution, while VFD algorithm utilization bridges objective and subjective ratings.
Open-source telemedicine platform for wireless medical video communication. An underwater optical wireless communication system based on LED source. Compared with other communication methods, optical wireless communication OWC holds the merits of higher transmitting rate and sufficient secrecy. So it is an efficacious communicating measure for data transmitting between underwater carriers. A small pumped-multiple-tube PMT was used as the detector to increase the communicating range, and FPGA chips were employed to code and decode the communicating data.
Public lighting represents a large part of the energy consumption of towns and cities. Efficient management of public lighting can entail significant energy savings. This work presents a smart system for managing public lighting networks based on wireless communication and the DALI protocol. Wireless communication entails significant economic savings, as there is no need to install new wiring and visual impacts and damage to the facades of historical buildings in city centers are avoided.
The DALI protocol uses bidirectional communication with the ballast, which allows its status to be controlled and monitored at all times. The novelty of this work is that it tackles all aspects related to the management of public lighting: a standard protocol, DALI, was selected to control the ballast, a wireless node based on the IEEE Securing communications in wireless sensor networks is increasingly important as the diversity of applications increases.
However, even today, it is equally important for the measures employed to be energy efficient. For this reason, this publication analyzes the suitability of various cryptographic primitives for use in WSNs according to various criteria and, finally, describes a modular, PKI-based framework for confidential, authenticated, secure communications in which most suitable primitives can be employed.
Due to the limited capabilities of common WSN motes, criteria for the selection of primitives are security, power efficiency and memory requirements. The implementation of the framework and the singular components have been tested and benchmarked in our testbed of IRISmotes. Next-generation optical wireless communications for data centers.
Data centers collect and process information with a capacity that has been increasing from year to year at an almost exponential pace. Therefore, a technology-shift from the fiber and cable to wireless has already been initiated in order to meet the required data-rate, flexibility and scalability demands for next-generation data center network interconnects.
Optical wireless communication OWC , or free space optics FSO , is one of the most effective wireless technologies that could be used in future data centers and could provide ultra-high capacity, very high cyber security and minimum latency, due to the low index of refraction of air in comparison to fiber technologies. In this paper we review the main concepts and configurations for next generation OWC for data centers.
Two families of technologies are reviewed: the first technology regards interconnects between rack units in the same rack and the second technology regards the data center network that connects the server top of rack TOR to the switch. A comparison between different network technologies is presented. Integration of analytical measurements and wireless communications --current issues and future strategies. Rapid developments in wireless communications are opening up opportunities for new ways to perform many types of analytical measurements that up to now have been restricted in scope due to the need to have access to centralised facilities.
This paper will address both the potential for new applications and the challenges that currently inhibit more widespread integration of wireless communications with autonomous sensors and analytical devices. Key issues are identified and strategies for closer integration of analytical information and wireless communications systems discussed.
Accurate measurement of RF exposure from emerging wireless communication systems. Isotropic broadband probes or spectrum analyzers SAs may be used for the measurement of rapidly varying electromagnetic fields generated by emerging wireless communication systems. In this paper this problematic is investigated by comparing the responses measured by two different isotropic broadband probes typically used to perform electric field E-field evaluations. The legacy measurement protocols should be adapted to cope for the emerging wireless communication technologies based on the OFDM modulation scheme.
This is not easily achieved except when the statistics of the RF emission are well known. In this case the measurement errors are shown to be systematic and a correction factor or calibration can be applied to obtain a good approximation of the total RMS power. Optical wireless communications to OC and beyond. Laser and LED-based wireless communication systems are currently providing license-free interconnection for broadband voice, data and video transport. These systems allow for the immediate, reliable and low-cost extension of copper and fiber-based networks to any end user, providing efficient First Mile bypass access to high data rate backbone networks at speeds ranging from T-1 voice to full throughput ATM at Mbps and up to Gigabit Ethernet.
These wireless optical beams constitute a Virtual Fiber in the air, providing the capabilities of fiber in situations where wired connectivity is unavailable, impractical, expensive or slow-to-implement, while achieving a combination of low cost, speed and reliability that cannot be matched by microwave, mm wave, spread spectrum or other competing actually complementary wireless technologies.
The carrier frequency of the optical beam is about 10, times higher than the highest frequencies used by the millimeter wave technology. By means of Wavelength Division Multiplexing more than independent data channels can be projected into the air on a single beam thus providing a potential bandwidth ten million times that of any RF solution. The twin barriers of physics and regulatory bureaucracy to this essentially infinite wireless bandwidth are thus eliminated by this Virtual Fiber.
As user density and individual bandwidth needs escalate, the optical wireless will be the preferred medium of choice in both network and cellular interconnection. A mesh topology which integrates our optical wireless systems with the latest Optical Access switches and routing equipment will be described using case study examples from Japan to South America.
As the Bandwidth Blowout continues to push the limits of electronics and especially in the case of DWDM Dense Wavelength Division Multiples , the conventional optical wireless solutions are no longer feasible. Instead of using f. Communication protocol in chassis detecting wireless transmission system based on WiFi. In chassis detecting wireless transmission system, the wireless network communication protocol plays a key role in the information exchange and synchronization between the host and chassis PDA.
Confidential Treatment from Patricia J. Paoletta and Jonathan B. Mirsky, Counsel to Wireless Properties of As the rollout of 4G mobile communication networks takes place, representatives of industry and academia have started to look into the technological developments toward the next generation 5G. Several research projects involving key international mobile network operators, infrastructure manufacturers, and academic institutions, have been launched recently to set the technological foundations of 5G. However, the architecture of future 5G systems, their performance, and mobile services to be provided have not been clearly defined.
In this paper, we put forth the vision for 5G as the convergence of evolved versions of current cellular networks with other complementary radio access technologies. Therefore, 5G may not be a single radio access interface but rather a "network of networks". Evidently, the seamless integration of a variety of air interfaces, protocols, and frequency bands, requires paradigm shifts in the way networks cooperate and complement each other to deliver data rates of several Gigabits per second with end-to-end latency of a few milliseconds. We provide an overview of the key radio technologies that will play a key role in the realization of this vision for the next generation of mobile communication networks.
We also introduce some of the research challenges that need to be addressed. Nonlocality and Short-Range Wetting Phenomena. We propose a nonlocal interfacial model for 3D short-range wetting at planar and nonplanar walls. The model is characterized by a binding-potential functional depending only on the bulk Ornstein-Zernike correlation function, which arises from different classes of tubelike fluctuations that connect the interface and the substrate.
Robust Wireless Communications for Industry 4.0
The theory provides a physical explanation for the origin of the effective position-dependent stiffness and binding potential in approximate local theories and also obeys the necessary classical wedge covariance relationship between wetting and wedge filling. Renormalization group and computer simulation studies reveal the strong nonperturbative influence of nonlocality at critical wetting, throwing light on long-standing theoretical problems regarding the order of the phase transition.
Nonlocality and short-range wetting phenomena. Interactive computation of coverage regions for indoor wireless communication. This paper describes a system which assists in the strategic placement of rf base stations within buildings. Known as the site modeling tool SMT , this system allows the user to display graphical floor plans and to select base station transceiver parameters, including location and orientation, interactively.
The system then computes and highlights estimated coverage regions for each transceiver, enabling the user to assess the total coverage within the building. For single-floor operation, the user can choose between distance-dependent and partition- dependent path-loss models. Similar path-loss models are also available for the case of multiple floors. This paper describes the method used by the system to estimate coverage for both directional and omnidirectional antennas.
The site modeling tool is intended to be simple to use by individuals who are not experts at wireless communication system design, and is expected to be very useful in the specification of indoor wireless systems. Performance evaluation of wireless communications through capsule endoscope.
This paper presents a performance evaluation of wireless communications applicable into a capsule endoscope. A numerical model to describe the received signal strength RSS radiated from a capsule-sized signal generator is derived through measurements in which a liquid phantom that has equivalent electrical constants is used. By introducing this model and taking into account the characteristics of its direction pattern of the capsule and propagation distance between the implanted capsule and on-body antenna, a cumulative distribution function CDF of the received SNR is evaluated.
Then, simulation results related to the error ratio in the wireless channel are obtained. These results show that the frequencies of MHz or lesser would be useful for the capsule endoscope applications from the view point of error rate performance. Further, we show that the use of antenna diversity brings additional gain to this application.
The objectives to be achieved are high peak data rates in high spectrum bandwidth and high spectral efficiencies. Technically, pre-coding means that multiple data streams are emitted from the transmit antenna with independent and appropriate weightings such that the link throughput is maximized at the receiver output thus increasing or equalizing the received signal to interference and noise SINR across the multiple receiver terminals.
However, it is not reliable enough to fully utilize the information transfer rate to fit the condition of channel according to the bandwidth size. Thus, adaptive pre-coding is proposed. It applies pre-coding matrix indicator PMI channel state making it possible to change the pre-coding codebook accordingly thus improving the data rate higher than fixed pre-coding.
Tabassum, E. Hossain, A Wireless Commun. Wireless and satellite communications are a rapidly growing industries which are slated for explosive growth into emerging countries as well as countries with advanced economies. The dominant trend in wireless communication systems is towards broadband applications such as multimedia file transfer, video transmission and Internet access. These applications require much higher data transmission rates than those currently used for voice transmission applications. To achieve these higher data rates, substantially larger bandwidths and higher carrier frequencies are required.
A key roadblock to implementing these systems at K-band In this chapter, we report on the status of tunable dielectric thin films for devices, such as resonators, filters, phased array antennas, and tunable oscillators, which utilize nonlinear tuning in the control elements. Paraelectric materials such as Barium Strontium Titanate Ba, Sr TiO3 have dielectric constants which can be tuned by varying the magnitude of the electric field across the material. Currently, tunable dielectric devices are being developed for applications which require high tunability, low loss, and good RF power-handling capabilities at microwave and millimeter-wave frequencies.
These properties are strongly impacted by film microstructure and device design, and considerable developmental work is still required. However, in the last several years enormous progress has occurred in this field, validating the potential of tunable dielectric technology for broadband wireless communication applications. In this chapter we summarize how film processing techniques, microwave test. Communication techniques and challenges for wireless food quality monitoring. Remote measurement of product core temperature is an important prerequisite to improve the cool chain of food products and reduce losses.
This paper examines and shows possible solutions to technical challenges that still hinder practical applications of wireless sensor networks in the field of food transport supervision. The high signal attenuation by water-containing products limits the communication range to less than 0. Communication protocols have to provide compatibility with widely accepted standards for integration into the global Internet, which has been achieved by programming an implementation of the constrained application protocol for wireless sensor nodes and integrating into IPv6-based networks.
The sensor's battery lifetime can be extended by optimizing communication protocols and by in-network pre-processing of the sensor data. The feasibility of remote freight supervision was demonstrated by our full-scale 'Intelligent Container' prototype. In order for future aerospace propulsion systems to meet the increasing requirements for decreased maintenance, improved capability, and increased safety, the inclusion of intelligence into the propulsion system design and operation becomes necessary.
These propulsion systems will have to incorporate technology that will monitor propulsion component conditions, analyze the incoming data, and modify operating parameters to optimize propulsion system operations. This implies the development of sensors, actuators, and electronics, with associated packaging, that will be able to operate under the harsh environments present in an engine.
However, given the harsh environments inherent in propulsion systems, the development of engine-compatible electronics and sensors is not straightforward. The ability of a sensor system to operate in a given environment often depends as much on the technologies supporting the sensor element as the element itself. If the supporting technology cannot handle the application, then no matter how good the sensor is itself, the sensor system will fail. An example is high temperature environments where supporting technologies are often not capable of operation in engine conditions.
Further, for every sensor going into an engine environment, i. The communication wires may be within or between parts, or from the engine to the controller. As more hardware is added, more wires, weight, complexity, and potential for unreliability is also introduced. Thus, wireless communication combined with in-situ processing of data would significantly improve the ability to include sensors into high temperature systems and thus lead toward more intelligent engine systems.
Distributed architecture for prognostics is an essential step in prognostic research in order to enable feasible real-time system health management. Communication overhead is an important design problem for such systems. In this paper we focus on communication issues faced in the distributed implementation of an important class of algorithms for prognostics - particle filters.
In spite of being computation and memory intensive, particle filters lend well to distributed implementation except for one significant step - resampling. We propose new resampling scheme called parameterized resampling that attempts to reduce communication between collaborating nodes in a distributed wireless sensor network. Analysis and comparison with relevant resampling schemes is also presented.
A battery health management system is used as a target application. A new resampling scheme for distributed implementation of particle filters has been discussed in this paper. Analysis and comparison of this new scheme with existing resampling schemes in the context for minimizing communication overhead have also been discussed. Our proposed new resampling scheme performs significantly better compared to other schemes by attempting to reduce both the communication message length as well as number total communication messages exchanged while not compromising prediction accuracy and precision.
Future work will explore the effects of the new resampling scheme in the overall computational performance of the whole system as well as full implementation of the new schemes on the Sun SPOT devices. Exploring different network architectures for efficient communication is an importance future research direction as well. Wireless communication links for brain-machine interface applications.
Recent technological developments have given neuroscientists direct access to neural signals in real time, with the accompanying ability to decode the resulting information and control various prosthetic devices and gain insight into deeper aspects of cognition. These developments - along with deep brain stimulation for Parkinson's disease and the possible use of electro-stimulation for other maladies - leads to the conclusion that the widespread use electronic brain interface technology is a long term possibility.
This talk will summarize the various technical challenges and approaches that have been developed to wirelessly communicate with the brain, including technology constraints, dc power limits, compression and data rate issues. Ultrafast all-optical technologies for bidirectional optical wireless communications. In this Letter, a spherical retro-modulator architecture is introduced for operation as a bidirectional transceiver in passive optical wireless communication links. It is found that the S-LAH79 structure provides the optimal refraction and nonlinearity for the desired retroreflection and modulation capabilities.
The wireless microphone is a lightweight, portable, wireless voice communications device for use by the crew of the space shuttle orbiter. The wireless microphone allows the crew to have normal hands-free voice communication while they are performing various mission activities. The unit is designed to transmit at or kilohertz and employs narrow band FM modulation.
Two orthogonally placed antennas are used to insure good reception at the receiver. Background: Teaching wireless communications and networking is not an easy task because it involves broad subjects and abstract content. Methodology: A pedagogical method that combined lectures, labs, assignments, exams,…. This guidebook is divided into four parts: Part 1. Planning and Managing a Communications Project: Discusses the overall scope of a project, including planning, funding, procurement, and management. Part 2. Wireless Communications Technology: Discuss In this paper, a new compact wideband monopole antenna is presented for wireless communication applications.
This antenna comprises of a new radiating patch, a new arc-shaped strip, microstrip feed line, and a notched ground plane.
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The proposed radiating patch is combined with a rectangular and semi-circular patch and is integrated with a partial ground plane to provide a wide impedance bandwidth. The new arc-shaped strip between the radiating patch and microstrip feed line creates an extra surface on the patch, which helps further widen the bandwidth. Inserting one step notch on the ground plane further enhances the bandwidth. Stable radiation patterns with acceptable gain are achieved.
Also, a measured bandwidth of This antenna is compatible with a good number of wireless standards, including UWB band, Wimax 5. An improved broadband E patch microstrip antenna for wireless communications. A broadband probe-fed microstrip antenna with E-shaped patch on a single-layer air substrate is investigated. Bandwidth enhancement of the antenna is achieved by inserting two parallel slots into its radiating patch. The effects of the antenna parameters are analyzed, and their optimal values for broadband operation are obtained. The design parameters are formulated as a function of the center frequency, and the empirical equations are validated by simulation.
A comparison between simulated and measured results is presented, and it showed satisfactory agreement. Moreover, the effect of incorporating more parallel slots into the radiating patch is investigated. Flash floods warning technique based on wireless communication networks data.
Flash floods can occur throughout or subsequent to rainfall events, particularly in cases where the precipitation is of high-intensity. Unfortunately, each year these floods cause severe property damage and heavy casualties. At present, there are no sufficient real time flash flood warning facilities found to cope with this phenomenon. Here we show the tremendous potential of flash floods advanced warning based on precipitation measurements of commercial microwave links. As was recently shown, wireless communication networks supply high resolution precipitation measurements at ground level while often being situated in flood prone areas, covering large parts of these hazardous regions.
We present the flash flood warning potential of the wireless communication system for two different cases when floods occurred at the Judean desert and at the northern Negev in Israel. In both cases, an advanced warning regarding the hazard could have been announced based on this system. This work was also supported by a grant from the Yeshaya Horowitz Association, Jerusalem. This model consists of a power station, an information receiver and multiple users that can work in either BackCom mode or harvest-then-transmit HTT mode. The time block is mainly divided into two parts corresponding to the data backscattering and transmission periods, respectively.
The users first backscatter data to the information receiver in time division multiple access TDMA during the data backscattering period. When one user works in the BackCom mode, the other users harvest energy from the power station. During the data transmission period, two schemes, i. To maximize the system throughput, the optimal time allocation policies are obtained. Simulation results demonstrate the superiority of the proposed model. Docket No. Amendment of part 27 of its rules to Govern the Operation of Wireless Communications Services in the 2.
Wireless infrared indoor communications : how to combat the multipath distortion. The present investigation deals with one of the most prospective candidates for high-speed in-house wireless communications , namely, Multi-Spot Diffusing Configuration MSDC. Since it uses optical medium for data transmission, it possesses inherent potential for achieving very high capacity level. Channel characteristics in MSDC are simulated and the causes for channel distortion are analyzed. Then, conditions for creation of a virtually ideal channel are derived. It is shown that the 3 dB-channel bandwidth can be extended up to frequencies beyond 2 GHz.
The large bandwidth comes at the cost of poor power efficiency. In order to compensate for this, a novel receiver optical front-end design is proposed and its performance is analyzed. Taking advantage of unique properties of holographic optical elements, conventional optical front-end consisting of a concentrator and a filter, is replaced by a single holographic curved mirror. Utilization of such a holographic optical element improves the signal-to-shot noise ratio by up to Wireless networking intensify the tractability in the home and office environment to connect the internet without wires but at the cost of risks associated with stealing the data or threat of loading malicious code with the intention of harming the network.
In this paper, we proposed a novel method of establishing a secure and reliable communication link using optical wireless communication OWC. For security, spatial diversity based transmission using two optical transmitters is used and the reliability in the link is achieved by a newly proposed method for the construction of structured parity check matrix for binary Low Density Parity Check LDPC codes. Experimental results show that a successful secure and reliable link between the transmitter and the receiver can be achieved by using the proposed novel technique. Demand for high data rate wireless communications is pushing up amplifier power, bandwidth and frequency requirements.
Some systems are using vacuum electron devices again because solid-state power amplifiers are not able to efficiently meet the new requirements. The traveling wave tube is the VED of choice because of its excellent broadband capability as well as high power efficiency and frequency. But TWTs are very expensive on a per watt basis below about watts of output power.
We propose a new traveling wave tube that utilizes cathode ray tube construction technology and electrostatic focusing. We discuss several traveling wave tube slow wave circuits that lend themselves to the new construction. We will present modeling results and data on prototype devices. In this paper, we propose and experimentally demonstrate a multiple-input multiple-output orthogonal frequency division multiplexing MIMO-OFDM underwater wireless optical communication UWOC system, with a gross bit rate of The system is capable of realizing robust data transmission within a relatively large reception area, leading to relaxed alignment requirement for UWOC.
New approach to wireless data communication in a propagation environment. This paper presents a new idea of perfect signal reconstruction in multivariable wireless communications systems including a different number of transmitting and receiving antennas. The proposed approach is based on the polynomial matrix S-inverse associated with Smith factorization. Crucially, the above mentioned inverse implements the so-called degrees of freedom. It has been confirmed by simulation study that the degrees of freedom allow to minimalize the negative impact of the propagation environment in terms of increasing the robustness of whole signal reconstruction process.
Now, the parasitic drawbacks in form of dynamic ISI and ICI effects can be eliminated in framework described by polynomial calculus. Therefore, the new method guarantees not only reducing the financial impact but, more importantly, provides potentially the lower consumption energy systems than other classical ones. In order to show the potential of new approach, the simulation studies were performed by author's simulator based on well-known OFDM technique. Review of optical wireless communications for data centers. A data center DC is a facility either physical or virtual, for running applications, searching, storage, management and dissemination of information known as cloud computing, which consume a huge amount of energy.
A DC includes thousands of servers, communication and storage equipment and a support system including an air conditioning system, security, monitoring equipment and electricity regulator units. Data center operators face the challenges of meeting exponentially increasing demands for network bandwidth without unreasonable increases in operation and infrastructure cost. In order to meet the requirements of moderate increase in operation and infrastructure cost technology, a revolution is required.
Reliable Communications for Short-Range Wireless Systems - Google книги
One way to overcome the shortcomings of traditional static wired data center architectures is use of a hybrid network based on fiber and optical wireless communication OWC or free space optics FSO. In that case the network topology is flexible and adapts quickly to changes in traffic, heat distribution, power consumption and characteristics of the applications.
In addition, OWC could provide an easy way to maintain and scale up data centers. As a result total cost of ownership could be reduced and the return on investment could be increased. In this talk we will review the main OWC technologies applicable for data centers, indicate how energy could be saved using OWC multichannel communication and discuss the issue of OWC pointing accuracy for data center scenario. The challenge study is a project based learning curriculum at Technical High School aimed at the construction of a wireless communication system.
The first period was engineering issues in the construction of an artificial satellite and the second period was a positional locating system based on the general purpose wire-less device--ZigBee device.
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