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Transmission Delay (transmission + delay)
Selected AbstractsNovel stability criteria for bidirectional associative memory neural networks with time delaysINTERNATIONAL JOURNAL OF CIRCUIT THEORY AND APPLICATIONS, Issue 5 2002Xiaofeng Liao Abstract In this paper, the bidirectional associative memory (BAM) neural network with axonal signal transmission delay is considered. This model is also referred to as a delayed dynamic BAM model. By combining a number of different Lyapunov functionals with the Razumikhin technique, some sufficient conditions for the existence of a unique equilibrium and global asymptotic stability of the network are derived. These results are fairly general and can be easily verified. Besides, the approach for the analysis allows one to consider several different types of activation functions, including piecewise linear sigmoids with bounded activations as well as C1 -smooth sigmoids. It is believed that these results are significant and convenient in the design and applications of BAM neural networks. Copyright © 2002 John Wiley & Sons, Ltd. [source] Performance evaluation of CSMA/ID MAC protocol for IP over WDM ring networksINTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 11 2008Jih-Hsin Ho Abstract In this paper, a packet pre-classification media access control protocol based on a carrier sense multiple access with idle detection (CSMA/ID) scheme is investigated for supporting IP packets over all-optical WDM ring networks. The purpose of the protocol is to increase throughput and to decrease the packet transmission delay of IP packets over optical networks in a metropolitan area network. This protocol avoids both packet collision and packet fragmentation. In order to improve the utilization of the network, the packets transmitted from a local area network are first pre-classified into various class queues of an access point (AP) according to their length. After checking the available space based on the wavelength received by the receivers of the AP, the packets in the queues are transmitted. An analytical model is developed to evaluate the performance of the protocol, with simulation results showing good network efficiency. The proposed network has short-term variations that introduce unfairness conditions. This problem could be overcome by assigning a quota on individual queues to allow all queues fair access. Copyright © 2008 John Wiley & Sons, Ltd. [source] Dynamic bandwidth recycle algorithm for OVSF,CDMA systemsINTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 3 2006Peng-Jung Wu Abstract This paper presents a dynamic bandwidth recycle algorithm in the downlink of a WCDMA system using orthogonal variable spreading factor codes (OVSF). It consists of a bandwidth recycle algorithm and a bandwidth reservation algorithm. The bandwidth recycle algorithm is used to recycle bandwidth from current serviced connections when the system does not have enough available bandwidth to support a bandwidth request. The bandwidth reservation algorithm is used to reduce transmission delay caused by suddenly increasing bandwidth requests. Four traffic classes, conversational, streaming, interactive, and background classes, defined by universal mobile telecommunication system (UMTS) are considered. Simulation results show that the bandwidth utilization and block rate are improved, the bandwidth guaranteed to conversational and streaming classes are protected, and the delay time of interactive and background classes are kept under an acceptable value even when the traffic load is heavy. Copyright © 2005 John Wiley & Sons, Ltd. [source] The distribution of file transmission duration in the webINTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 5 2004R. Nossenson Abstract It is well known that the distribution of files transmission duration in the Web is heavy-tailed (A practical guide to Heavy Tails: Statistical Techniques and Application. Birkhauser: Boston, 1998; 3,26). This paper attempts to understand the reasons for this phenomenon by isolating the three major factors influencing the transmission duration: file size, network conditions and server load. We present evidence that the transmission-duration distribution (TDD) of the same file from the same server to the same client in the Web is Pareto and therefore heavy tailed. Furthermore, text files transmission delay for a specific client/server pair is not significantly affected by the file sizes: all files transmitted from the same server to the same client have very similar transmission duration distributions, regardless of their size. We use simulations to estimate the impact of network conditions and server load on the TDD. When the server and the client are on the same local network, the TDD of each file is usually Pareto as well (for server files and client requests that are distributed in a realistic way). By examining a wide-area network situation, we conclude that the network conditions do not have a major influence on the heavy-tailed behaviour of TDD. In contrast, the server load is shown to have a significant impact on the high variability of this distribution. Copyright © 2004 John Wiley & Sons, Ltd. [source] ARCMA,adaptive request channel multiple access protocol for wireless ATM networksINTERNATIONAL JOURNAL OF NETWORK MANAGEMENT, Issue 6 2001Professor Anna Ha We propose a new multiple access protocol based on demand assignment. This protocol is designed to reduce contention in the request phase while minimizing transmission delay under various network (ATM) environments. Our protocol uses an adaptive scheme that changes under heavy traffic conditions, and also provides priority to certain delay-sensitive traffic. Copyright © 2001 John Wiley & Sons, Ltd. [source] End-to-end network delay model for heavy-tailed environmentsEUROPEAN TRANSACTIONS ON TELECOMMUNICATIONS, Issue 5 2003David Muñoz-Rodríguez Adequate quality of Internet Protocol (IP) services demand low transmission delays. However, packets traveling in a network are subject to a variety of delays that degrade severely the quality of service in real-time applications. This paper presents a general packet jitter-assessment methodology for a multi-node path in the presence of heavy-tailed traffic. Using the extreme-value theory, it is shown that delay performance is governed by a proposed networking-processing factor |T|lambda dependent on the traffic characteristics, the processing time along the path segments and the number of nodes in a route. |T|lambda allows the establishment of design constraints and the definition of a feasibility space for a routing algorithm in order to guarantee a quality of service (QoS). Copyright © 2003 AEI. [source] Efficient integration of isochronous and data bursty traffics in low earth orbit-mobile satellite systems,INTERNATIONAL JOURNAL OF SATELLITE COMMUNICATIONS AND NETWORKING, Issue 3 2002Alessandro Andreadis Abstract This paper focuses on the radio resource management in low earth orbit-mobile satellite systems (LEO-MSSs) based on a time division multiple access (TDMA) air interface. A novel demand,assignment medium access control (MAC) protocol, named DRAMA+ (dynamic resource assignment multiple access,enhanced version), is proposed, where voice and Web traffic sources obtain transmission slots through requests sent by means of a random access phase. The round-trip propagation delay (RTD) of LEO-MSSs prevents an immediate feedback for each transmission attempt. Therefore, the main concern of the DRAMA+ scheme is to realize an efficient access phase. All the transmission requests successfully received at the satellite are managed by an on board scheduler. We have shown that DRAMA+ outperforms other techniques appeared in the literature in terms of voice quality, transmission delays for bursty data traffics and resource utilization. Moreover, a performance analysis of an ideal version of the DRAMA+ scheme has permitted us to prove the potentialities of the proposed DRAMA+ technique. Stability issues have been addressed as well as the impact on the DRAMA+ performance of the LEO satellite constellation RTD value. Copyright © 2002 John Wiley & Sons, Ltd. [source] Controller design for natural and robotic systems with transmission delaysJOURNAL OF FIELD ROBOTICS (FORMERLY JOURNAL OF ROBOTIC SYSTEMS), Issue 5 2002Abhay Kataria Robust stability and two-dimensional trajectory following problems are considered for n -link robotic systems with transmission delays. Such problems appear in telerobotics, where the controller is physically far from the robot, and in neural control of musculo-skeletal (biological) systems, where muscle actuation and neural sensing are subject to time delays. A typical second-order nonlinear dynamical model is taken with input and output time delays. In a prior work by the authors, a control strategy was developed for stable movement of the planar linkage system, using the standard Q -parameterization and solving an H, control problem to determine the free parameter. In this article, a new control scheme is proposed to eliminate the steady-state errors seen in the tracking performance of the controller derived in the earlier work. Simulation examples are shown to demonstrate the effectiveness of the proposed control methodology. © 2002 Wiley Periodicals, Inc. [source] | ||||||||||||||||||||||