Download or read book Frequency Hopped Spread Spectrum Packet Radio Networks written by KHAIRI ASHOUR. MOHAMED and published by . This book was released on 1993 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Packet error probabilities in frequency hopped spread spectrum packet radio networks Markos frequency hopping patterns considered written by M. Georgiopoulos and published by . This book was released on 1987 with total page 58 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Random Access Algorithm for Frequency Hopped Spread Spectrum Packet Radio Networks written by and published by . This book was released on 1986 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors consider packet radio multi-user spread-spectrum environments, where frequency hopping spread spectrum techniques are deployed for protection against intelligent adversaries. When the users in such environments are mobile and bursty, random access frequency hopping transmission algorithms should be adopted, for efficiency in throughput and delay control. This paper proposes and analyzes such an algorithm, named Collision Resolution Algorithm for Frequency Hopping (CRAFH). The CRAFH is a limited sensing random access algorithm utilizing receiver oriented frequency hopping patterns. In its design, the experience from random access algorithms for non spread spectrum multi-user channels is utilized. Utilizing the regenerative character of the induced by the algorithm transmission process, the authors compute throughputs and expected per packet delays. In the presence of interferences between transmissions to different receivers, we compute throughputs, subject to an upper bound on the probability of erroneous data decoding. The CRAFH induces uniformly good delays within its stability region, and is particularly appropriate for environments where the users are highly mobile.
Download or read book Packet Error Probabilities in Frequency Hopped Spread Spectrum Packet Radio Networks Markov Frequency Hopping Patterns Considered written by M. Georgiopoulos and published by . This book was released on 1987 with total page 31 pages. Available in PDF, EPUB and Kindle. Book excerpt: We compute the packet error probability induced in a frequency-hopped spread spectrum packet radio network, which utilizes first order Markov frequency hopping patterns. The frequency spectrum is divided into q frequency bins and the packets are divided into M bytes each. Every user in the network sends each of the M bytes of his packet at a frequency bin, which is different from the frequency bin used by the previous byte, but equally likely to be any one of the remaining q-1 frequency bins (Markov frequency hopping patterns). Furthermore, different users in the network utilize statistically independent frequency hopping patterns. Provided that, K users have simultaneously transmitted their packets on the channel, and a receiver has locked on to one of these K packets, we present a method for the computation of P sub e (K) (i.e. the probability that this packet is incorrectly decoded). Furthermore, we present numerical results (i.e. P sub e (K) versus K) for various values of the multiple access interference K, when Reed Solomon (RS) codes are used for the encoding of packets. Finally, some useful comparisons, with the packet error probability induced, if we assume that the byte errors are independent, are made; based on these comparisons, we can easily evaluate the performance of our spread spectrum system.
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 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 Spread Spectrum in Mobile Communication written by Olav Berg and published by IET. This book was released on 1998 with total page 480 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presenting a technology that adapts radio communication to computational data information processing networks, first reviews the concepts of modern mobile communication and the user requirements and operational environment that influence the design of mobile systems. Then focuses on mobility issues for a decentralized network topology and the effects of spread spectrum modulation on radios used in packet-switched networks. Shows how connecting radio terminals using packet switching provides a highly flexible and efficient solution for mobile users. Annotation copyrighted by Book News, Inc., Portland, OR
Download or read book Frequency Hop Spread Spectrum Packet Radio with Hermitian Codes written by and published by . This book was released on 2000 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hermitian codes are an attractive alternative to Reed-Solomon codes for use in frequency-hop (FH) spread-spectrum packet radio networks. For a given alphabet size a Hermitian code has a much longer block length than a Reed-Solomon code. This and other considerations suggest that Hermitian codes may be superior for certain applications. Analytical results are developed for the evaluation of the packet error probability for FH transmissions using Hermitian coding. We find there are several situations for which Hermitian codes provide much lower packet error probabilities than can be obtained with Reed-Solomon codes. In general, as the code rate decreases or the symbol alphabet size increases the relative performance of the Hermitian codes improves with respect to the Reed-Solomon codes. Performance evaluations are presented for an additive white Gaussian noise channel and for certain partial-band interference channels, and the packet error probability is evaluated for both errors-only and errors-and-erasures decoding.
Download or read book Spread Spectrum Mobile Radio Communications written by S. C. Gupta and published by . This book was released on 1984 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this report, we present some additional results on the performance of Frequency Hopped Multilevel FSK (FH-MFSK) systems under mobile environment. This is followed by a review on packet radio networks and some results on the performance of a packet transmission technique in mobile radio channels. Simulation studies confirm the theoretical performance estimate of a FH-MFSK hard-limited receiver operating under adjacent cell interference conditions. Both simulation and approximate theoretical considerations testify the usefulness of a nonparametric receiver based on rank-sums. This receiver also possesses a robustness against changing probability models. It is believed that this receiver is a competing alternative to the parametric receivers, such as the hard-limited receiver. Originator-supplied keywords include: Spread Spectrum, Mobile Radio, Packet transmission, Packet Radio Network; and Adjacent Cell Interference.
Download or read book Spread Spectrum Radio Networks written by Michael B. Pursley and published by . This book was released on 1987 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the final report for Contract DAAG29-84-K-008 (ARO Proposal 21576-EL) for the period June 22, 1984 to July 20, 1987. Keywords: Packet radio networks, Frequency-hop packet radio, Error-control coding, and Time-hopping.
Download or read book Poetry from Bombay written by Jagdish Shivpuri and published by . This book was released on 1977 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Use of Side Information in Adaptive Protocols for Spread Spectrum Packet Radio Networks written by and published by . This book was released on 1995 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: A summary of the results obtained in research sponsored by the Army Research Office under contract DAALO3-92-c-0018 and conducted during the period July 1, 1992 to August 31, 1995 is presented. Reliable data distribution within spread spectrum packet radio networks requires high performance from the network protocols. The high variability of the qualities of the links and the unique characteristics of frequency hop spread spectrum signaling impose special requirements for network protocols that are to be employed in frequency hop packet radio networks. Side information that can be extracted from the received spread spectrum signals that are embedded in noise and interference provides information about the quality of the links in the packet radio network. This research investigated several techniques for utilizing side information to aid the network protocols in establishing reliable routes in a mobile, tactical packet radio network.
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 A Design Concept for Reliable Mobile Radio Networks with Frequency Hopping Signaling written by Anthony Ephremides and published by . This book was released on 1988 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: The design of a packet radio network must reflect the operational requirements and environmental constraints which it is subject. In this report we outline those features that distinguish the High Frequency (HF) Intra Task Force (ITF) Network form other packet radio networks, and we present a design concept for this network that encompasses organizational structure, waveform design, and channel access. Network survivability is achieved through the use of distributed network control and frequency-hopping spread-spectrum signaling. We show how the execution of the fully distributed Linked Cluster Algorithm can enable a network to reconfigure itself when it is affected by connectivity changes such as those resulting from jamming. Additional resistance against jamming is provided by frequency hopping, which leads naturally to the use of code division multiple access (CDMA) techniques that permit the simultaneous successful transmission by several users. Distributed algorithms that exploit CDMA properties have been developed to schedule contention-free transmissions for much of the channel access in this network. Contention-based channel access protocols can also be implemented in conjunction with the Linked Cluster network structure. The design concept presented in this report provides a high degree of survivability and flexibility to accommodate changing environment conditions and user demands. (RH).
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 Throughput and Delay Characteristics for a Slow Frequency Hopped Aircraft to Aircraft Packet Radio Network written by Scott R. Harrison and published by . This book was released on 1990 with total page 123 pages. Available in PDF, EPUB and Kindle. Book excerpt: Current lack of data transfer capability between tactical aircraft results in decreased mission effectiveness or the need to equip every aircraft with all the sensors and data processing equipment to perform each task expected of them. In the Air Force, these developments established the need for aircraft-to-aircraft data communications so that navigation, threat and targeting information could be shared within a flight and so that digital voice communications could also be maintained. Data rates within a flight of fighter aircraft to support these requirements will need to be between 100 and 250 kilobits/second (KBPS) and between 2.4 KBPS and 16 KBPS between the flight and a command and control aircraft. Other sources place the former figure as high as 512 KBPS. To increase the security of these radio channels, against both jamming and intrusion, anti-jam and low probability of interception (LPI) techniques must be used. One method of achieving these capabilities is to use spread spectrum techniques such as frequency hopping. The Air Force is currently concentrating its efforts around the Joint Tactical Information Distribution System (JTIDS). This system is, however, lacking in data rate capacity, LPI capability, and, while it is jam-resistant, it does not have anti-jam capabilities. This thesis seeks to develop a mathematical representation of a frequency hopping, aircraft-to-aircraft, packet radio network, in order to obtain baseline figures for the bandwidth required and delay for such a system. (edc).
Download or read book On Distributed Spread Spectrum Packet Radio Networks written by Elvino Silveira Sousa and published by . This book was released on 1985 with total page 346 pages. Available in PDF, EPUB and Kindle. Book excerpt:
