The Experts below are selected from a list of 18519 Experts worldwide ranked by ideXlab platform
Harlan B. Russell - One of the best experts on this subject based on the ideXlab platform.
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A protocol for construction of Broadcast Transmission schedules in mobile ad hoc networks
IEEE Transactions on Wireless Communications, 2007Co-Authors: Brian J. Wolf, Joseph L. Hammond, D.l. Noneaker, Harlan B. RussellAbstract:In a mobile ad hoc network using Broadcast Transmission scheduling, a terminal that is ready to join the network must first determine the current state of the Transmission-scheduling protocol. In order to transmit and receive packets without interference, the new terminal needs to notify other terminals of its presence and exchange information with them so that it can form a collision-free Broadcast Transmission schedule. A new distributed protocol is described that allows a new terminal to acquire sufficient information about the terminals in its local neighborhood so that it can efficiently integrate itself into the existing Transmission schedule. The protocol is also designed to enable a group of terminals to form a new Transmission schedule if one does not already exist. We show that a large group of terminals can quickly form a new and efficient collision-free Transmission schedule
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Distributed formation of Broadcast Transmission schedules for mobile ad hoc networks
IEEE MILCOM 2004. Military Communications Conference 2004., 1Co-Authors: Brian J. Wolf, Joseph L. Hammond, D.l. Noneaker, Harlan B. RussellAbstract:In a mobile ad hoc packet radio network using Transmission scheduling, when a terminal boots and is ready to join the network, it has no knowledge of the network's current state. In order to send and receive packets without interference, the new terminal must have some means of notifying other terminals of its presence and exchanging information with them so that it can form a collision free Broadcast Transmission schedule. We demonstrate the performance of a distributed protocol designed to allow a new terminal to acquire sufficient information about its local environment to achieve collision free Transmissions. Furthermore, we show that changes to the network are limited to the new terminal's local neighborhood. As a result, the size of the overall network has very little effect on the performance of the protocol. The protocol is not only effective in adding a new terminal; it can also organize a group of terminals into a new network. This is demonstrated for the extreme case of all terminals powering up simultaneously. The overall performance of the algorithm depends primarily on the density of the network and rate at which changes occur in the network.
James R. Redford - One of the best experts on this subject based on the ideXlab platform.
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Television Broadcast Transmission Standards
Encyclopedia of RF and Microwave Engineering, 2005Co-Authors: Alan S. Godber, James R. RedfordAbstract:Since the invention of television, images and sound have been captured, processed, transmitted, received, and displayed using analog technology, where the picture and sound elements are represented by signals that are proportional to the image amplitude and sound volume. In more recent years, as solid-state technology has developed, spurred primarily by the development of computers, digital technology has gradually been introduced into the handling of the television signal, both for image and sound. Many portions of television systems are now hybrid combinations of analog and digital, and it is expected that eventually all television equipment will be fully digital, except for the transducers, cameras, and microphones (whose inputs are analog) and the television displays and loudspeakers (whose outputs are analog). Keywords: rate conversion; common image format; scanning; analog television; packets
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Television Broadcast Transmission Standards
Encyclopedia of Imaging Science and Technology, 2002Co-Authors: Alan S. Godger, James R. RedfordAbstract:Since the invention of television, the images and sound have been captured, processed, transmitted, received, and displayed using analog technology, where the picture and sound elements are represented by signals that are proportional to the image amplitude and sound volume. More recently, as solid-state technology has developed, spurred primarily by the development of computers, digital technology has gradually been introduced into handling the television signal, both for image and sound. The digital electric signal representing the various elements of the image and sound is composed of binary numbers that represent the image intensity, color, and so on, and the sound characteristics. Many portions of television systems are now hybrid combinations of analog and digital, and it is expected that eventually all television equipment will be fully digital, except for the transducers, cameras, and microphones (whose inputs are analog) and the television displays and loudspeakers (whose outputs are analog). The currently used Broadcast television Transmission standards [National Television Systems Committee (NTSC), phase alternate line (PAL) and sequential and memory (SECAM)] for 525- and 625-line systems were designed around analog technology, and although significant portions of those Broadcast systems are now hybrid analog/digital or digital, the “over the air” Transmission system is still analog. Furthermore, other than for “component” processed portions of the system, the video signals take the same “encoded” form from studio camera to receiver and conform to the same standard. The recently developed ATSC Digital Television Standard, however, uses digital technology for “over the air” Transmission, and the digital signals used from the studio camera to the receiver represent the same image and sound, but differ in form in portions of the Transmission system. This variation is such that in the studio, maximum image and sound information is coded digitally, but during recording, special effects processing, distribution around a Broadcast facility, and Transmission, the digital signal is “compressed” to an increasing extent as it approaches its final destination at the home. This permits practical and economical handling of the signal. Keywords: analog TV; black and white TV; multichannel sound; NTSC color TV; sequential and memory (SECAM); phase alternate line (PAL); component analog video; digital video; advanced TV systems; japanese systems; european systems
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Wiley Encyclopedia of Electrical and Electronics Engineering - Television Broadcast Transmission Standards
Wiley Encyclopedia of Electrical and Electronics Engineering, 1999Co-Authors: Alan S. Godber, James R. RedfordAbstract:The sections in this article are 1 Analog Television Systems 2 Advanced Television Systems, Current and Future 3 Acknowledgments
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television Broadcast Transmission standards
Wiley Encyclopedia of Electrical and Electronics Engineering, 1999Co-Authors: Alan S. Godber, James R. RedfordAbstract:The sections in this article are 1 Analog Television Systems 2 Advanced Television Systems, Current and Future 3 Acknowledgments
Muwen Huang - One of the best experts on this subject based on the ideXlab platform.
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A Broadcast Engagement ACK Mechanism for Reliable Broadcast Transmission in Mobile Ad Hoc Networks
IEICE Transactions on Communications, 2005Co-Authors: Jenhui Chen, Muwen HuangAbstract:How to safely or reliably flood a packet via Broadcast scheme to all nodes in computer networks is an important issue. However, it is a big challenge and critical problem to Broadcast data packets over mobile ad hoc networks reliably due to the unsettled wireless links, high mobility, and the lack of the acknowledgment (ACK) scheme. Many solutions deal with this problem by adopting multiple unicast Transmissions to achieve reliable Broadcast Transmission in network layer. Unfortunately, it will cause severe duplicate Transmissions and thus rapidly consume the limited network bandwidth. One simplest way to solve this drawback is to Broadcast data packets in data link layer. But a serious problem will be arisen that replied ACK frames will collide at the sending node if we enforce each mobile node to reply an ACK after receiving the Broadcast data frame. Therefore, in order to overcome the thorny problem, we proposed a Broadcast engagement ACK mechanism (BEAM), which is completely compatible with the IEEE 802.11 protocol, for reliable Broadcast Transmission in the data link layer. We also show that the overhead of raising the reliability of Broadcast Transmission in network layer would be significantly reduced in data link layer. Simulation results show that the proposed BEAM can reach approximate 100% reliability even in heavy traffic load. We also indicate that the BEAM could be combined with other network layer Broadcast schemes to approach higher flooding ratio as well as reduce bandwidth consumption effectively. key words: ad hoc, Broadcast, network, MAC, reliability, wireless
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A Broadcast engagement ACK mechanism for reliable Broadcast Transmission in mobile ad hoc networks : Special section on advances in ad hoc mobile communications and networking
IEICE Transactions on Communications, 2005Co-Authors: Jenhui Chen, Muwen HuangAbstract:How to safely or reliably flood a packet via Broadcast scheme to all nodes in computer networks is an important issue. However, it is a big challenge and critical problem to Broadcast data packets over mobile ad hoc networks reliably due to the unsettled wireless links, high mobility, and the lack of the acknowledgment (ACK) scheme. Many solutions deal with this problem by adopting multiple unicast Transmissions to achieve reliable Broadcast Transmission in network layer. Unfortunately, it will cause severe duplicate Transmissions and thus rapidly consume the limited network bandwidth. One simplest way to solve this drawback is to Broadcast data packets in data link layer. But a serious problem will be arisen that replied ACK frames will collide at the sending node if we enforce each mobile node to reply an ACK after receiving the Broadcast data frame. Therefore, in order to overcome the thorny problem, we proposed a Broadcast engagement ACK mechanism (BEAM), which is completely compatible with the IEEE 802.11 protocol, for reliable Broadcast Transmission in the data link layer. We also show that the overhead of raising the reliability of Broadcast Transmission in network layer would be significantly reduced in data link layer. Simulation results show that the proposed BEAM can reach approximate 100% reliability even in heavy traffic load. We also indicate that the BEAM could be combined with other network layer Broadcast schemes to approach higher flooding ratio as well as reduce bandwidth consumption effectively.
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PAPER Special Section on Advances in Ad Hoc Mobile Communications and Networking A Broadcast Engagement ACK Mechanism for Reliable Broadcast Transmission in Mobile Ad Hoc Networks
2005Co-Authors: Jenhui Chen, Muwen Huang, NonmemberAbstract:SUMMARY How to safely or reliably flood a packet via Broadcast scheme to all nodes in computer networks is an important issue. However, it is a big challenge and critical problem to Broadcast data packets over mobile ad hoc networks reliably due to the unsettled wireless links, high mobility, and the lack of the acknowledgment (ACK) scheme. Many solutions deal with this problem by adopting multiple unicast Transmissions to achieve reliable Broadcast Transmission in network layer. Unfortunately, it will cause severe duplicate Transmissions and thus rapidly consume the limited network bandwidth. One simplest way to solve this drawback is to Broadcast data packets in data link layer. But a serious problem will be arisen that replied ACK frames will collide at the sending node if we enforce each mobile node to reply an ACK after receiving the Broadcast data frame. Therefore, in order to overcome the thorny problem, we proposed a Broadcast engagement ACK mechanism (BEAM), which is completely compatible with the IEEE 802.11 protocol, for reliable Broadcast Transmission in the data link layer. We also show that the overhead of raising the reliability of Broadcast Transmission in network layer would be significantly reduced in data link layer. Simulation results show that the proposed BEAM can reach approximate 100% reliability even in heavy traffic load. We also indicate that the BEAM could be combined with other network layer Broadcast schemes to approach higher flooding ratio as well as re
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BEAM: Broadcast engagement ACK mechanism to support reliable Broadcast Transmission in IEEE 802.11 wireless ad hoc networks
IEEE 60th Vehicular Technology Conference 2004. VTC2004-Fall. 2004, 1Co-Authors: Jenhui Chen, Muwen HuangAbstract:To transfer a Broadcast packet safely to all nodes in computer networks is an important issue. However, it is a big challenge to transfer Broadcast packets over wireless networks reliably due to the unsettled wireless links and the lack of an acknowledgment (ACK) scheme. Therefore, we propose a reliable Broadcast scheme named Broadcast engagement ACK mechanism (BEAM) which is completely compatible with the IEEE 802.11 protocol. BEAM is in the data link layer rather than the network layer. This is because the overhead of raising the reliability of Broadcast Transmission in the network layer can be significantly reduced in the data link layer. Simulation results show that BEAM can reach approximately 100% reliability, even in heavy traffic load. Besides, by using the proposed mechanism, the IEEE 802.11 protocol can provide the reliability of unicast Transmissions as well as Broadcast Transmissions and avoid redundant control overhead.
Lajos Hanzo - One of the best experts on this subject based on the ideXlab platform.
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a survey of digital television Broadcast Transmission techniques
IEEE Communications Surveys and Tutorials, 2013Co-Authors: Mohammed Elhajja, Lajos HanzoAbstract:This paper is a survey of the Transmission techniques used in digital television (TV) standards worldwide. With the increase in the demand for High-Definition (HD) TV, video-on-demand and mobile TV services, there was a real need for more bandwidth-efficient, flawless and crisp video quality, which motivated the migration from analogue to digital Broadcasting. In this paper we present a brief history of the development of TV and then we survey the Transmission technology used in different digital terrestrial, satellite, cable and mobile TV standards in different parts of the world. First, we present the Digital Video Broadcasting standards developed in Europe for terrestrial (DVB-T/T2), for satellite (DVB-S/S2), for cable (DVB-C) and for hand-held Transmission (DVB-H). We then describe the Advanced Television System Committee standards developed in the USA both for terrestrial (ATSC) and for hand-held Transmission (ATSC-M/H). We continue by describing the Integrated Services Digital Broadcasting standards developed in Japan for Terrestrial (ISDB-T) and Satellite (ISDB-S) Transmission and then present the International System for Digital Television (ISDTV), which was developed in Brazil by adopteding the ISDB-T physical layer architecture. Following the ISDTV, we describe the Digital Terrestrial television Multimedia Broadcast (DTMB) standard developed in China. Finally, as a design example, we highlight the physical layer implementation of the DVB-T2 standard.
Brian J. Wolf - One of the best experts on this subject based on the ideXlab platform.
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A protocol for construction of Broadcast Transmission schedules in mobile ad hoc networks
IEEE Transactions on Wireless Communications, 2007Co-Authors: Brian J. Wolf, Joseph L. Hammond, D.l. Noneaker, Harlan B. RussellAbstract:In a mobile ad hoc network using Broadcast Transmission scheduling, a terminal that is ready to join the network must first determine the current state of the Transmission-scheduling protocol. In order to transmit and receive packets without interference, the new terminal needs to notify other terminals of its presence and exchange information with them so that it can form a collision-free Broadcast Transmission schedule. A new distributed protocol is described that allows a new terminal to acquire sufficient information about the terminals in its local neighborhood so that it can efficiently integrate itself into the existing Transmission schedule. The protocol is also designed to enable a group of terminals to form a new Transmission schedule if one does not already exist. We show that a large group of terminals can quickly form a new and efficient collision-free Transmission schedule
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Distributed formation of Broadcast Transmission schedules for mobile ad hoc networks
IEEE MILCOM 2004. Military Communications Conference 2004., 1Co-Authors: Brian J. Wolf, Joseph L. Hammond, D.l. Noneaker, Harlan B. RussellAbstract:In a mobile ad hoc packet radio network using Transmission scheduling, when a terminal boots and is ready to join the network, it has no knowledge of the network's current state. In order to send and receive packets without interference, the new terminal must have some means of notifying other terminals of its presence and exchanging information with them so that it can form a collision free Broadcast Transmission schedule. We demonstrate the performance of a distributed protocol designed to allow a new terminal to acquire sufficient information about its local environment to achieve collision free Transmissions. Furthermore, we show that changes to the network are limited to the new terminal's local neighborhood. As a result, the size of the overall network has very little effect on the performance of the protocol. The protocol is not only effective in adding a new terminal; it can also organize a group of terminals into a new network. This is demonstrated for the extreme case of all terminals powering up simultaneously. The overall performance of the algorithm depends primarily on the density of the network and rate at which changes occur in the network.
