Download or read book Performance Evaluation of Frequency Hopped Spread Spectrum Multi Hop Networks written by J. W. Gluck and published by . This book was released on 1988 with total page 55 pages. Available in PDF, EPUB and Kindle. Book excerpt: Primary and secondary multiple-access interference processes are characterized for multi-hop packet radio networks, in which users are assumed to be Poisson-distributed in the plane and to use frequency hopped spread-spectrum signaling with a receiver-oriented assignment of frequency-hopping patterns. The throughput per node and the average forward progress are then evaluated for frequency-hopped multi-hop networks that employ (i) random forward routing with fixed transmission radius (RFR) and(ii) most forward progress routing with fixed transmission radius (MFR). The optimal average number of neighbors and transmission radius are derived for these cases when Reed-Solomon forward-error-control coding with minimum distance decoding or binary convolutional coding with Viterbi decoding is employed.

Download or read book Expected Forward Progress and Throughput of Multi Hop Frequency Hopped Spread Spectrum Networks written by and published by . This book was released on 1987 with total page 53 pages. Available in PDF, EPUB and Kindle. Book excerpt: Secondary multiple-access interference processes are characterized for multi-hop packet radio networks in which users are assumed to be Poisson-distributed in the plane and to use frequency-hopped spread-spectrum signaling with a receiver-oriented assign- ment of frequency-hopping patterns. The throughput per node and the average forward progress are then evaluated for frequency-hopped multi-hop networks which employ (i) random forward routing with fixed transmission radius (RFR) and (ii) most forward pro- gress routing with fixed transmission radius (MF%R). The optimal average number of neighbors and transmission radius are derived for these cases when Reed-Solomon forward-error-control coding with minimum distance decoding or binary convolutional coding with Viterbi decoding is employed.

Download or read book Performance Analysis of Multihop Packet Radio Networks Under Slotted Frequency Hopping Access Scheme written by Hahan Rahardjo and published by . This book was released on 1987 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 704 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Probability of Multiple Correct Packet Receptions in a Multireceiver Frequency Hopped Spread Spectrum System written by and published by . This book was released on 1991 with total page 49 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this report we develop exact expressions and approximations for the probability of exactly l correct packet receptions in a group of m receivers, given that k packets are transmitted simultaneously from users employing frequency-hopping spread-spectrum (FH/SS) and Reed-Solomon (RS) coding. This quantity is essential for the design and performance evaluation of multiple-access protocols in spread-spectrum packet radio networks. The evaluations are carried out for MFSK modulation with noncoherent demodulation and various types of RS minimum-distance decoding with erasures and/or errors decoding. Packet synchronous FH/SSMA systems that are hop-synchronous or hop- asynchronous are considered. The exact expressions developed have computational complexity that grows exponentially with m, thus making their evaluation for large m prohibitive. In light of such difficulties, two approximations are considered: one based on Gaussian multivariate distributions with linear computational requirements in m and k, and another based on the assumption of independent receiver operation (IROA), which has minimum computational complexity. Extensive comparisons of the approximations with the exact results establish their validity over different ranges of the system parameters. (Author).

Download or read book Performance Study of Modified Frequency Hopping Spread Spectrum Multiple Access Packet Communication Systems written by Ki Jong Hong and published by . This book was released on 1982 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Performance of Cellular Frequency Hopped Spread Spectrum Radio Networks written by Jeffrey W. Gluck and published by . This book was released on 1989 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt: Multiple access interference is characterized for cellular mobile networks, in which users are assumed to be Poisson-distributed in the plane and employ frequency-hopped spread-spectrum signaling with transmitter-oriented assignment of frequency-hopping patterns. Exact expressions for the bit error probabilities are derived for binary coherently demodulated systems without coding. Approximations for the packet error probability are derived for coherent and noncoherent systems and these approximations are applied when forward-error-control coding is employed. In all cases, the effects of varying interference power are accurately taken into account according to some propagation law. Numerical results are given in terms of bit error probability for the exact case and throughput for the approximate analyses. Comparisons are made with previously derived bounds and it is shown that these tend to be very pessimistic. Keywords: Communications network; Multiple access; Frequency hopping; Spread spectrum; Error control coding. (jhd).

Download or read book Performance Analysis of Frequency Hopped Spread Spectrum Multiple Access FH SSMA Communication Systems written by Khalid Ali Qaraq'e and published by . This book was released on 1997 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Performance Analysis for Fast Frequency Hopped Spread Spectrum Multiple Access Communications written by E. A. Geraniotis and published by . This book was released on 1981 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Performance Analysis of Multi Channel and Multi Traffic on Wireless Communication Networks written by Wuyi Yue and published by Springer Science & Business Media. This book was released on 2007-05-08 with total page 335 pages. Available in PDF, EPUB and Kindle. Book excerpt: With the rapidly increasing penetration of laptop computers and mobile phones, which are primarily used by mobile users to access Internet s- vices like e-mail and World Wide Web (WWW) access, support of Internet services in a mobile environment is an emerging requirement. Wireless n- works have been used for communication among fully distributed users in a multimedia environment that has the needs to provide real-time bursty traffic (such as voice or video) and data traffic with excellent reliability and service quality. To satisfy the huge wireless multimedia service demand and improve the system performance, efficient channel access methods and analytical methods must be provided. In this way very accurate models, that faithfully reproduce the stochastic behavior of multimedia wireless communication and computer networks, can be constructed. Most of these system models are discrete-time queueing systems. Queueing networks and Markov chains are commonly used for the p- formance and reliability evaluation of computer, communication, and m- ufacturing systems. Although there are quite a few books on the individual topics of queueing networks and Markov chains, we have found none that covers the topics of discrete-time and continuous-time multichannel mul- traffic queueing networks. On the other hand, the design and development of multichannel mul- hop network systems and interconnected network systems or integrated n- works of multimedia traffic require not only such average performance m- sures as the throughput or packet delay but also higher moments of traffic departures and transmission delay.

Download or read book Performance of Fast Frequency hopping Diversity Combiners in Multiple Access Interference for Ad Hoc Networks written by Helene Ejenyi Tayong and published by . This book was released on 2006 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this work is to evaluate the performance of fast frequency-hopping diversity combiners in multiple access interference for ad hoc networks. Multiple access interference (MAI) is the interference that is common in a network with many devices sharing the channel. A model developed in, i.e. the alpha-stable distribution suggested for modeling impulsive signals, is investigated to characterize MAI for an ad hoc network. Impulsive processes are characterized by the presence of spikes or extreme outliers. As such, their probability density functions (pdfs) have heavier tails. Such impulsive behaviors have been verified experimentally in various radio and underwater acoustic channels. The characteristic exponent (the parameter alpha) controls the impulsive behavior of the process. Techniques based on characteristic functions, the Fourier transform of the probability density function (pdf), are used to calculate the probability of error since no-closed form exists for their distributions. Frequency-hopping spread spectrum (FHSS) multiple access radio networks using the same modulation and power is considered. FHSS is a powerful technique used in communication systems to provide protection against jamming and fading. The problem is applicable in wireless random-access communication systems where information about transmitters' positions is not provided. The signal strength attenuates with distance. The focus is on Fast Frequency-hopping (FFH) in order to exploit frequency diversity; a condition where the same data bit is transmitted on multiple independently faded hops. A modulation technique called frequency hopping multilevel frequency shift keying (FH-MFSK) is used to allow many users to effectively share the same frequency band. The Reduced Fuzzy Rank Order Detector (R-FROD), a FFH diversity combiner is studied in this interference environment and its performance is compared with that of hard decision majority vote (HDMV) detector, maximum rank sum receiver (MRSR) and order statistic normalized envelope detector (OS-NED). Simulation results show that the R-FROD is able to outperform the MRSR, OS-NED and HDMV detectors across a range of values for alpha. R-FROD is analyzed in alpha-stable environment using Gaussian and Cauchy membership functions. Simulation results show that either membership function can be used in R-FROD to analyze its performance in an alpha-stable environment. Increasing the hop sequence length reduces the probability of error. The analysis presented is important in the design of efficient interference suppression techniques and in solving mobile wireless communication systems. -- Abstract.

Download or read book Government Reports Annual Index written by and published by . This book was released on with total page 1668 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sections 1-2. Keyword Index.--Section 3. Personal author index.--Section 4. Corporate author index.-- Section 5. Contract/grant number index, NTIS order/report number index 1-E.--Section 6. NTIS order/report number index F-Z.

Download or read book Security for Multihop Wireless Networks written by Shafiullah Khan and published by CRC Press. This book was released on 2014-04-15 with total page 540 pages. Available in PDF, EPUB and Kindle. Book excerpt: Security for Multihop Wireless Networks provides broad coverage of the security issues facing multihop wireless networks. Presenting the work of a different group of expert contributors in each chapter, it explores security in mobile ad hoc networks, wireless sensor networks, wireless mesh networks, and personal area networks. Detailing technologies and processes that can help you secure your wireless networks, the book covers cryptographic coprocessors, encryption, authentication, key management, attacks and countermeasures, secure routing, secure medium access control, intrusion detection, epidemics, security performance analysis, and security issues in applications. It identifies vulnerabilities in the physical, MAC, network, transport, and application layers and details proven methods for strengthening security mechanisms in each layer. The text explains how to deal with black hole attacks in mobile ad hoc networks and describes how to detect misbehaving nodes in vehicular ad hoc networks. It identifies a pragmatic and energy efficient security layer for wireless sensor networks and covers the taxonomy of security protocols for wireless sensor communications. Exploring recent trends in the research and development of multihop network security, the book outlines possible defenses against packet-dropping attacks in wireless multihop ad hoc networks.Complete with expectations for the future in related areas, this is an ideal reference for researchers, industry professionals, and academics. Its comprehensive coverage also makes it suitable for use as a textbook in graduate-level electrical engineering programs.

Download or read book Research in Progress written by and published by . This book was released on 1990 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Who s Who American Law Students written by and published by . This book was released on 1992 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book New Topics in Theoretical Computer Science written by Oleg N. Terikhovsky and published by Nova Publishers. This book was released on 2008 with total page 346 pages. Available in PDF, EPUB and Kindle. Book excerpt: Theoretical computer science focuses on the more abstract, logical and mathematical aspects of computing, such as the theory of computation, analysis of algorithms and semantics of programming languages. This new book presents the latest research in the field from around the globe.

Download or read book Technical Reports Awareness Circular TRAC written by and published by . This book was released on 1988 with total page 492 pages. Available in PDF, EPUB and Kindle. Book excerpt: