Showing papers on "Communications system published in 2006"

Chaos-based communications at high bit rates using commercial fibre-optic links

Abstract: A thorough study of an all-optical chaotic communication system, including experimental realization real-world testing and performance characterization through bit-error-rate analysis, is presented. Pseudorandom data that are effectively encrypted in the chaotic emitter and sent for transmission are recovered at the receiver with bit-error-rate (BER) values as low as 10-7 for 1 Gb/s data rate. Different data code lengths and bit-rates at the Gb/s region have been tested. Optical transmission using 100km fiber spools in an in-situ experiment and 120km in an installed optical network showed that chaotic communication systems does not act as a considerably deteriorating factor in the final performance.

Cooperation in Wireless Networks: Principles and Applications

Abstract: Cooperation in Wireless Networks: Principles and Applications covers the underlying principles of cooperative techniques as well as several applications demonstrating the use of such techniques in practical systems. The work is written in a collaborative manner by several authors from Asia, America, and Europe. Twenty chapters introduce and discuss in detail the main cooperative strategies for the whole communication protocol stack from the application layer down to the physical layer. Furthermore power saving strategies, security, hardware realization, and user scenarios for cooperative communication systems are introduced and discussed. The book also summarizes the strength of cooperation for upcoming generation of wireless communication systems, clearly motivating the use of cooperative techniques and pointing out that cooperation will become one of the key technologies enabling 4G and beyond. This book puts into one volume a comprehensive and technically rich view of the wireless communications scene from a cooperation point of view.

Wake up device for communications system

Abstract: The present invention teaches a communications system comprising a first communications device for receiving data and a wake up signal. The first communications device comprises an active mode of operation and a sleep mode of operation for reducing power consumption. Further, the system comprises means for switching the first communications device to and from sleep mode in response to receiving the wake up signal. Further, the system comprises a second communications device for transmitting data to the first device during its active mode, while transmitting the wake up signal to the first device during its sleep mode.

Coded Bi-directional Relaying

Abstract: In this paper, bi-directional traffic between two nodes communicating via a relay node is considered. A novel relaying method based on joint data packet encoding in conjunction with exploitation of a priori known information is presented. Moreover, a specially crafted method for combining of the direct and relayed radio signal is suggested. The proposed scheme enables a reduced number of transmissions, whereby enhancing aggregate throughput. Evaluation, where optimal power and rate settings are derived, shows that the proposed method enhances the throughput up to 33% as compared to a (traditional) four-phase bi-directional protocol under a system energy constraint, both with and without the proposed combining method

Reliability Analysis of DSRC Wireless Communication for Vehicle Safety Applications

Abstract: The 802.11-p based dedicated short range communication (DSRC) is being seriously considered as a promising wireless technology for enhancing transportation safety and highway efficiency. However, to-date, there is very little research done in characterizing the reliability of DSRC communication based on real-world experimental data, and its effect on the reliability of vehicle safety applications. Our experimental set-up includes a fleet of three vehicles equipped with DSRC communication system, GPS receiver and a number of vehicle safety applications based on vehicle-to-vehicle communication. This paper analyzes the link-level behavior of DSRC vehicle-to-vehicle communication in a wide variety of traffic environments based on real-world experimental data. In addition, we also characterize the application level reliability of DSRC for vehicle safety communication (VSC) system. Based on our experiments, we show that the reliability of DSRC vehicle-to-vehicle communication is adequate since packet drops do not occur in bursts most of the time. We also show that the application level reliability of VSC applications based on DSRC communication is quite satisfactory. Finally, we develop an analytical model to relate application level reliability with communication reliability and VSC system parameter, laying out a clear way to improve reliability of VSC applications under harsh traffic environments. To the best of our knowledge, this paper is the first to characterize the application-level reliability of DSRC communication for VSC applications based on real-world experimental data. Our findings develop a deep insight into significant characteristics of DSRC communication for highly mobile vehicle-to-vehicle wireless network, which will contribute to better design and evaluation of communication protocols for VSC applications in the future

Method and system for communicating information in a digital signal

Abstract: The present invention relates to a communication method, system and signal, and in particular to a method and system for communicating information in a digital signal. It has particular application to satellite or terrestrial packet-based multi-user radio communication systems. A method for communicating information in a digital signal comprising data symbols is disclosed, wherein the information is encoded in a sequence characteristic of pilot symbols distributed amongst the data symbols, such that a receiver is able to determine the sequence characteristic and retrieve the transmitted information. The invention allows information to be encoded into a sequence characteristic of pilot symbols, rather than relying on modulating such information onto the pilot symbols themselves. This allows a significantly larger number of pieces of information to be transmitted than hitherto possible, and the technique is more resistant to large frequency errors than prior techniques.

Ultra-wideband channel model for communication around the human body

Abstract: Using ultra-wideband (UWB) wireless sensors placed on a person to continuously monitor health information is a promising new application. However, there are currently no detailed models describing the UWB radio channel around the human body making it difficult to design a suitable communication system. To address this problem, we have measured radio propagation around the body in a typical indoor environment and incorporated these results into a simple model. We then implemented this model on a computer and compared experimental data with the simulation results. This paper proposes a simple statistical channel model and a practical implementation useful for evaluating UWB body area communication systems.

Antennas and Propagation for Body Centric Communications

Abstract: Body centric wireless communication is now accepted as an important part of 4th generation (and beyond) mobile communications systems, taking the form of human to human networking incorporating wearable sensors and communications. There are also a number of body centric communication systems for specialized occupations, such as paramedics and fire-fighters, military personnel and medical sensing and support. To support these developments there is considerable ongoing research into antennas and propagation for body centric communications systems, and this paper will summarise some of it, including the characterisation of the channel on the body, the optimisation of antennas for these channels, and communications to medical implants where advanced antenna design and characterisation and modelling of the internal body channel are important research needs. In all of these areas both measurement and simulation pose very different and challenging issues to be faced by the researcher.

Vehicle immersive communication system

Abstract: A vehicle communication system facilitates hands-free interaction with a mobile device in a vehicle or elsewhere. Users interact with the system by speaking to it. The system processes text and processes commands. The system supports Bluetooth wireless technology for hands-free use. The system handles telephone calls, email, and SMS text messages. The user can customize the device via a user profile stored on an Internet web server.

Wireless ground link-based aircraft data communication system with roaming feature

Abstract: A flight information communication system has a plurality of RF direct sequence spread spectrum ground data links that link respective aircraft-resident subsystems, in each of which a copy of its flight performance data is stored, with airport-located subsystems. The airport-located subsystems are coupled by way communication paths, such as land line telephone links, to a remote flight operations control center. At the flight operations control center, flight performance data downlinked from plural aircraft parked at different airports is analyzed. In addition, the flight control center may be employed to direct the uploading of in-flight data files, such as audio, video and navigation files from the airport-located subsystems to the aircraft.

Antennas and propagation for body centric communications

Abstract: Body centric wireless communication is now accepted as an important part of 4th generation (and beyond) mobile communications systems, taking the form of human to human networking incorporating wearable sensors and communications. There are also a number of body centric communication systems for specialized occupations, such as paramedics and fire-fighters, military personnel and medical sensing and support. To support these developments there is considerable ongoing research into antennas and propagation for body centric communications systems, and this paper will summarise some of it, including the characterisation of the channel on the body, the optimisation of antennas for these channels, and communications to medical implants where advanced antenna design and characterisation and modelling of the internal body channel are important research needs. In all of these areas both measurement and simulation pose very different and challenging issues to be faced by the researcher.

Power line sensornet - a new concept for power grid monitoring

Abstract: Significant work has been done on the sensing of utility assets. Most proposed approaches have been based on the principle of using few relatively expensive sensors and wireless communication links to provide a sample of data on the status of the power line. This paper introduces the concept of a distributed power line sensornet (PLS) as an alternative approach to realizing cost-effective power grid monitoring. By way of an example a distributed sensor module is proposed that can be clipped on to an existing power line and have the following four core functions: continuously monitoring critical line parameters in the immediate vicinity of the sensor; estimating the line status and identifying incipient faults in a changing environment; operating as a node of the sensornet communication system; power and fault management while allowing sensing and communication functions. Details of implementation and system impact are presented in the paper, along with simulation results.

Millimeter-wave communication system with directional antenna and one or more millimeter-wave reflectors

Abstract: Embodiments of millimeter-wave communication systems and methods for communicating using millimeter-waves are described. In some embodiments, a directional antenna (102) may direct millimeter-wave signals substantially in a horizontal plane (115), and one or more reflectors (104) may be positioned to reflect the millimeter-wave signals to user devices (108).

A remote sensing and communication system

Abstract: A remote sensing system and method for instrumenting the entries to manhole enclosures, in order to provide a platform and means f sensing environmental parameters within and around the enclosures and wirelessly transmitting those parameters to a distant site. T system comprises a housing (10) with sensor for monitoring environmental prararreter in the vicinity of the manhole. A microcontrol (12) in the housing sends the parameters to a radio module (13), which transmits the parameters to a communication device for alerting a user that a manhole has been tampered with.

Communication system for wireless audio devices

Abstract: The present subject matter provides a system for wireless communications between one or more wireless audio devices and other electronics for providing a rich set of streaming audio, control, programming and enhanced hearing functions.

Acoustic propagation considerations for underwater acoustic communications network development

Abstract: Underwater acoustic communications systems are significantly challenged by the acoustic propagation characteristics of the underwater environment. There are a wide range of physical processes that impact underwater acoustic communications and the relative importance of these processes are different in different environments. In this paper some relevant propagation phenomena are described in the context of how they impact the development and/or performance of underwater acoustic communications networks. The speed of sound and channel latency, absorption and spreading losses, waveguide effects and multipath, surface scattering, bubbles, and ambient noise are all briefly discussed.

Securing Vehicular Communications - Assumptions, Requirements, and Principles

Abstract: Among civilian communication systems, vehicular networks emerge as one of the most convincing and yet most challenging instantiations of the mobile ad hoc networking technology. Towards the deployment of vehicular communication systems, security and privacy are critical factors and significant challenges to be met. Thanks to the substantial research efforts carried out by the community so far, we make the following contributions in this paper: we outline security requirements for vehicular communication systems, we provide models for the system and the communication, as well as models for the adversaries, and propose a set of design principles for future security and privacy solutions for vehicular communication systems.

Control and Automation of Electrical Power Distribution Systems

Abstract: POWER DELIVERY SYSTEM CONTROL AND AUTOMATION Introduction Why Distribution Automation Power Delivery Systems Control Hierarchy What Is Distribution Automation Distribution Automation System Basic Architectures and Implementation Strategies for DA Definitions of Automated Device Preparedness Summary CENTRAL CONTROL AND MANAGEMENT Introduction Power System Operation Operations Environment of Distribution Networks Evolution of Distribution Management Systems Basic Distribution Management System Functions Basic of a Real-Time Control System (SCADA) Outage Management Decision Support Tools Subsystems Extended Control-Feeder Automation Performance Measures and Response Times Data Base Structures and Interfaces Conclusions Appendix 2A: Sample Comprehensive CIM Structure DESIGN, CONSTRUCTION AND OPERATION OF DISTRIBUTION SYSTEMS, MV NETWORKS Introduction Design of Networks LV Distribution Networks Switchgear for Distribution Substations and LV Networks Extended Control of Distribution Substations and LV Networks Summary HARDWARE FOR DISTRIBUTION SYSTEMS Introduction to Switchgear Primary Switchgear Ground Mounted Network Substations Larger Distribution/Compact Substations Pole Mounted Enclosed Switches Pole Mounted Reclosers Pole Mounted Switch Disconnectors and Disconnectors Operating Mechanisms and Actuators Current and Voltage Measuring Devices Instrument Transformers in Extended Control Current and Voltage Sensors PROTECTION AND CONTROL Introduction Protection Using Relays Sensitive Earth Fault and Instantaneous Protection Schemes Protection Using Fuses Earth Fault and Overcurrent Protection for Solid/ Resistance Earthed Networks Earth Faults on Compensated Networks Earth Faults on Unearthed Networks An Earth Fault Relay for Compensated and Unearthed Networks Fault Passage Indication Connection of the FPI to the Distribution System Conductor Distribution System Earthing and Fault Passage Indication AutoReclosing and Fault Passage Indicators The Choice of Indication between Phase Fault and Earth Fault Resetting the Fault Passage Indicator Grading of Fault Passage Indicators Selecting a Fault Passage Indicator Intelligent Electronic Device (IED) Power Supplies for Extended Control Automation Ready Switchgear - FA Building Blocks Examples of Building Blocks Typical Inputs and Outputs for Building Blocks Control Building Blocks and Retrofit Control Logic PERFORMANCE OF DISTRIBUTION SYSTEM Faults on Distribution Networks Performance and Basic Reliability Calculations Calculating the Effects of Extended Control Improving the Reliability of Underground Networks Improving the Reliability of Overhead Networks Improving Performance with Automation Improvements by Combining Design Methods on Underground Circuits COMMUNICATION SYSTEMS FOR CONTROL AND AUTOMATION Introduction Communications and Distribution Automation DA Communication Physical Link Options Wireless Communication Wire Communications Distribution Automation Communications Protocols Distribution Automation Communications Architecture DA Communications User Interface Some Considerations for DA Communications Selection Requirements for Dimensioning the Communications Channel Glossary of Communication Terms Used CREATING THE BUSINESS CASE Introduction Potential Benefits Perceived by the Industry for Substation Automation Potential Benefits Perceived by the Industry for Feeder Automation Generic Benefits Benefits Opportunity Matrix Benefits Flow Chart Dependencies, Shared and Unshared Benefits Capital Deferral, Release, or Displacement Savings in Manpower Savings Related to Energy Other Operating Benefits Summary of DA Functions and Benefits Economic Value-Cost Presentation of Results and Conclusion CASE STUDIES Introduction Case Study 1, Long Rural Feeder Case Study 2, Large Urban Network Glossary Index

Wireless communications system with parallel computing artificial intelligence-based distributive call routing

Abstract: The present invention is directed to devices and methods that provide a user of a decentralized asynchronous parallel-configured wireless communication system for voice, data and live digital video streaming communication with the ability to select various communication paths and calling bandwidths as needed. The system uses a novel Time-Shared Full Duplex (TSFD) protocol for communications. The TSFD protocol allows the transmission of live digital video signals from one wireless device to another wireless device. The system provides local communication as well as optional links to external networks, and does not require a synchronous centralized switching center. It further provides secure operation, emergency notification and a way to collect revenue from the system, and allows for control of the operational state of the internal network and optional remote control of the operational state control of systems external to the network.

Secure open-air communication system utilizing multi-channel decoyed transmission

Abstract: A secure, open-air communication system utilizes a plurality of “decoy” data signals to hide one or more true data signals. The true data signal(s) are channel hopped with the plurality of decoy data signals to form a multi-channel “scrambled” output signal that is thereafter transmitted in an open-air communication system. The greater the number of decoy signals, the greater the security provided to the open-air system. Further security may be provided by encrypting both the true and decoy signals prior to scrambling and/or by utilizing a spatially diverse set of transmitters and receivers. Without the knowledge of the channel assignment(s) for the true signal(s), an eavesdropper may be able to intercept (and, with time, perhaps descramble) the open-air transmitted signals, will not be able to distinguish the true data from the decoys without also knowing the channel assignment(s).

Power Line Communication Interface Device and Method

Abstract: A system for providing communications with a plurality of power distribution equipment via a broadband over power line communication system that provides broadband internet access to a plurality of consumers is provided. In one embodiment, the system may include a computer system having executable program code executable to generate control messages for controlling the plurality of power distribution automation equipment and a plurality of interface devices, wherein each interface device is communicatively coupled to one or more of the plurality of power distribution equipment. The computer system may be configured to transmit control messages to the plurality of power distribution equipment via a communication path that includes the broadband over power line communication system and the plurality of interface devices.

System and method for detecting noise source in a power line communications system

Abstract: A method for detecting noise location information in a power line distribution system is disclosed. In one embodiment, the method includes the steps of receiving link quality data for a first power line communication link between a first and second power line communications device, determining an asymmetry in the link quality data of the link, and determining location information for the noise source based on the location of the first power line communications device or the location of the second power line communications device.

Method for establishing power line communication link

Abstract: A method for providing power line communications in a multi-unit building is provided. One embodiment includes determining the quality of a communication link associated with each of a plurality of communication nodes, selecting one of the plurality of communication nodes based, at least in part, on the quality of the communication links associated with the communication nodes; and establishing communications with an external network through the selected one communication node. In addition, in some embodiments at least one of the communication links associated with the plurality of communication nodes includes a non-conductive radio frequency coupled segment.

Voice controlled multimedia and communications system

Abstract: A portable multimedia and communications device can include a transducive element for receiving sound The device also can include a base unit having a plurality of multimedia units and a processor executing a speech recognition engine for recognizing user speech Each of the plurality of multimedia units can be selectively enabled and operated responsive to user voice commands received via the transducive element and communicated to the base unit via a communication link

Distributed underwater electromagnetic communication system

Abstract: An extended underwater electromagnetic transducer is provided with an electrically insulated transmission line typically connected to a transmitter or receiver or transceiver system. The transmission line allows near-field communications with another transmitter or receiver or transceiver system. The transmission line provided is relatively long, the through water signal path length can be significantly reduced.

Method and apparatus for transmitting data in a time division duplexed (tdd) communication system

Abstract: Techniques to process data for transmission in a time division duplexed (TDD) communication system. In one aspect, the frequency response of a forward link is estimated at a base station based on reverse link transmissions (e.g., pilots) from a terminal. Prior to a data transmission on the forward link, the base station determines a reverse transfer function based on the pilots transmitted by the terminal, “calibrates” the reverse transfer function with a calibration function to derive an estimate of a forward transfer function, and preconditions modulation symbols based on weights derived from the forward transfer function. In another aspect, the terminal estimates the “quality” of the forward link and provides this information to the base station. The base station then uses the information to properly code and modulate data prior to transmission such that the transmitted data can be received by the terminal at the desired level of performance.

Content distribution & communication system for enhancing service distribution in short range radio environment

Abstract: A system for propagating information among wireless communication devices in an efficient manner. More specifically, the invention involves regulating the behavior of a wireless communication device (WCD) between a primarily passive mode where client or slave availability is maximized and a primarily active mode where information propagation or master behavior is maximized. The regulation of the WCD is controlled based on the environment surrounding the WCD, including the devices in effective transmission range of the device, and the current condition of the WCD.

Method and apparatus for maintaining a fingerprint for a wireless network

Abstract: The disclosure is directed to a mobile communication device that measures characteristics or attributes of a first communications network that vary according to physical location within that first communications network to create a fingerprint, or signature, of a location within the first communications network. When the fingerprint of the current location of the mobile device is created it can be compared to a known fingerprint associated with a second communication network to determine the mobile device's proximity to the second communications network. Furthermore, the second and subsequent fingerprint that are generated for a particular communications network can be used to modify the stored fingerprint so as to refine it to improve detecting the proximity to the communications network.

Vehicle communications using the internet

Abstract: Vehicle including a data generating system which obtains or generates information about the vehicle and a communications system coupled to the data generating system for communicating directly with a wireless Internet service provider (ISP) to enable the information obtained or generated by the data generating system to be transmitted via the Internet. The data generating system may be a diagnostic system which diagnoses the state of the vehicle or the state of a component of the vehicle and generates an output indicative or representative thereof. The data generating system may be arranged to obtain or generate information about the operation of the vehicle. Additionally or alternatively, the data generating system may be arranged to obtain or generate information about the presence of contents in the compartment and/or when contents are present, information about contents in the compartment.