Download or read book A Random Access Algorithm for Direct Sequence Spread Spectrum Packet Radio Networks written by Michael Georgiopoulos and published by . This book was released on 1986 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: We propose and analyze a limited sensing random access algorithm, named CRADS, for a multi-user and multi-receiver direct sequence spread spectrum system. Utilizing the regenerative character of the induced by the algorithm output process, we compute throughputs subject to an upper bound on the probability of erroneous data decoding; we also compute the expected per packet delays. The CRADS induces uniformly good delays within its stability region, an is particularly appropriate for environments where the users are highly mobile. (Author).
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 Throughput Analysis of a Random Access Tree Protocol for Spread Spectrum Packet Radio Networks written by Rajan Mani and published by . This book was released on 1988 with total page 178 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Research in Progress written by and published by . This book was released on 1991 with total page 274 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Random Access Algorithms in Multi user Communication Systems for Spread Spectrum and Non spread spectrum Environments written by Michael Georgiopoulos and published by . This book was released on 1986 with total page 294 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 1992 with total page 1572 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Sequence Selection for Spread spectrum Packet Radio Systems written by Mark Steven Schmidt and published by . This book was released on 1983 with total page 114 pages. Available in PDF, EPUB and Kindle. Book excerpt: A direct-sequence spread-spectrum scheme is applied to multiple-access packet radio systems. Algorithms that find signature sequence phases of Gold sequences with low correlation parameter values are explored. The average probabilities of error for sets of Gold sequences are shown to be dependent on the phases of the sequences. Keywords: Packet radio, Spread spectrum, Multiple access. (rh).
Download or read book Research in Progress written by United States. Army Research Office and published by . This book was released on 1983 with total page 316 pages. Available in PDF, EPUB and Kindle. Book excerpt: Vols. for 1977- consist of two parts: Chemistry, biological sciences, engineering sciences, metallurgy and materials science (issued in the spring); and Physics, electronics, mathematics, geosciences (issued in the fall).
Download or read book Bit to Bit Error Dependence in Direct Sequence Spread Spectrum Multiple Access Packet Radio Systems written by Robert K Morrow (Jr) and published by . This book was released on 1988 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt: Slotted direct-sequence spread-spectrum multiple-access (DS/SSMA) packet broadcasting systems with random signature sequences are analyzed within the framework of the lower three layers of the International Standards Organization Reference Model of Open Systems Interconnection. At the physical layer, we show that a widely-used Gaussian approximation (which we call the Standard Gaussian Approximation) for the probability of data bit error in a chip and phase asynchronous system is accurate only when there are a large number of simultaneous users on the channel; otherwise, this approximation can be optimistic by several orders of magnitude. For interfering signals with fixed delays and phases relative to the desired signal, however, the Standard Gaussian Approximation is quite accurate for any number of simultaneous users. To obtain a closer approximation to the probability of data bit error for an asynchronous system, we introduce the Improved Gaussian Approximation, which involves finding the distribution of the multiple-access interference variance over all possible delay and phase values and then taking a Gaussian approximation over the support of the distribution and averaging the results. To accurately analyze packet performance at the data link layer, we first use the theory of moment spaces to gain insight on the effect of bit-to-bit error dependence caused by the constant relative delays and (possibly) phases of the interfering signals over the duration of a desired packet. (rh).
Download or read book Throughput Performance of Spread Spectrum Multiple Access Packet Radio Networks written by James Scott Storey and published by . This book was released on 1986 with total page 410 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this dissertation, an integrated model of an unslotted spread spectrum multiple access (SSMA) packet radio network is developed. The model combines a detailed model of the radio channel, accounting for the effect of multi-user interference, with a network model that traces the evolution of the number of interfering transmissions and accounts for the half-duplex nature of the radios. A new analysis of the performance of a Viterbi decoder in a packet radio environment allows the model to be used for a system with convolutional Forward Error Correction (FEC) coding. The synchronization process is also analyzed and incorporated into the integrated model. The model makes use of several approximations for tractability. A discrete event simulation is used to validate these approximations. The integrated model leads to numerical results which show the throughput and the probability of success for a packet as a function of the channel level and network level parameters. Specifically, for the radio channel, these parameter include the modulation format, the received signal power, the spread spectrum bandwidth expansion, and the presence or absence of FEC coding. Also, the throughput is found as a function of the synchronization parameters, such as the detection thresholds and correlation times, for several different synchronization circuits and preamble structures. At the network level, the parameters are the traffic rate and the network size. The random access protocols considered include unslotted ALOHA and channel load sensing, which is an extension of carrier sensing to an SSMA network. (jhd).
Download or read book A Random Access Algorithm for Environments with Capture and Limited Feedback Capabilities written by P. Papantoni-Kazakos and published by . This book was released on 1988 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: We consider synchronous packet radio systems, deploying spread-spectrum encoding. In such systems, capture events occur, where in the presence of k simultaneous packet transmissions, a single packet is captured with probability P(k). We adopt the case where P(k) = p q to the (k-1) power, k = or> 1, for some system probabilities p and q, where ternary feedback per slot is available, where in the event of capture the identity of the captured packet is not revealed, and where capture in the presence of a single packet transmission and capture in the presence of multiple transmissions are not distinguishable events. For the above system, we present and analyze a full sensing window random access algorithm. Due to the system model considered, the algorithm inevitably induces losses. Its performance characteristics are the fraction of lost traffic and the per successfully transmitted packet expected delays. We compute the values of those characteristics, for various values of the system and the algorithmic parameters, and for the limit Poisson user model. The algorithm can attain low delays while simultaneously inducing relatively few losses.
Download or read book An Adaptive Transmission Protocol for Direct Sequence Spread Spectrum Packet Radio Networks written by Karthik Gajaraj and published by . This book was released on 2004 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Packet Radio Networks written by Clifford A. Lynch and published by Pergamon. This book was released on 1987 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ant Routing Searching and Topology Estimation Algorithms for Ad Hoc Networks written by Santpal Singh Dhillon and published by IOS Press. This book was released on 2008 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt: The idea of universal connectivity has led to the concept of ad hoc networks. Ad hoc networks are self-configuring, self-organizing networks that are formed on the fly. This book studies the performance of a dynamic, self-adaptive routing paradigm known as 'ant routing'; analyzing the behavior of searching and how it performs on graph topologies.
Download or read book Packet Radio Networks Under Dynamic Jamming written by and published by . This book was released on 1989 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this report is (a) to briefly review and classify the various research efforts developed so far in the broad area of Spread Spectrum (S2) Random-Access Packet Radio Networks (sometimes referred to as Code-Division Random-Access or CRDA) and (b) to point out certain directions that we perceive as being important to the Army, particularly in relation to the intelligent jamming of such networks. (JHD).
Download or read book Multiple Coupled Random Access Techniques for Packet Radio Networks written by Lawrence Charles Siegel and published by . This book was released on 1978 with total page 61 pages. Available in PDF, EPUB and Kindle. Book excerpt: The random accessing problem for packet radio networks is considered. The contention resolving tree algorithm of Capetanakis is applied to a model in which packets are transmitted by terminals and received by repeaters, with the possibility of geometries in which more than one repeater hears a single terminal. It is shown that naive applications of the tree algorithm of this multiple-coupled random access problem lead to algorithms which deadlock. A deadlock-free algorithm, restricted-entry algorithm for the multiple-coupled random access problem, is developed. The deadlock-free property is proved. An algorithm describing how new terminals join the network is presented. (Author).
Download or read book Networking and Computation written by Thomas G. Robertazzi and published by Springer Nature. This book was released on 2020-03-17 with total page 217 pages. Available in PDF, EPUB and Kindle. Book excerpt: This useful volume adopts a balanced approach between technology and mathematical modeling in computer networks, covering such topics as switching elements and fabrics, Ethernet, and ALOHA design. The discussion includes a variety of queueing models, routing, protocol verification and error codes and divisible load theory, a new modeling technique with applications to grids and parallel and distributed processing. Examples at the end of each chapter provide ample material for practice. This book can serve as an text for an undergraduate or graduate course on computer networks or performance evaluation in electrical and computer engineering or computer science.
