bluuebunny/crossref_metadata_2025_split huggingface dataset:
Queueing behaviour of two interconnected buffers of a packet network with application to the evaluation of packet routeing policies
Authors: Stavrakakis Ioannis 
Published: July 2007

AbstractIn this paper, the behaviour of two interconnected nodes of a packet communication network is analysed. The packet arrival process to the first node is described by an i.i.d. discrete time process. The packet arrival process to the second node consists of two mutually independent streams; one stream carries the packet output process from node 1; the other stream carries a packet traffic described by a dependent discrete time process. For this system, the following quantities are derived: (a) the first two moments of the buffer occupancy and the mean packet delay in the first node; (b) a description of the packet output process of the first node; (c) the first two moments of the buffer occupancy and the mean packet delay in the second node.In the sequel, the behaviour of the buffers is investigated under some simple routeing policies in node 1. The objective at this point is to evaluate the queueing behaviour of both buffers under some routeing policies and it is not to seek for the optimal packet routeing policy in the first node. It is shown how the routeing policy in node 1 can be incorporated in the description of the packet output process of node 1 and, then, the behaviour of buffer 2 be accurately evaluated.The numerical results show that the queueing behaviour of buffer 2 cannot be accurately evaluated by incorporating a Bernoulli approximation on the output process of node 1. Furthermore, it is shown that different routeing policies in the first node result in different intensities of the queueing problems in the second node, although the packet output rate from the first node is constant for all routeing policies considered. It turns out that a routeing policy which best randomizes the packet output process results in the least significant queueing problems in the second node. The latter implies that routeing decisions should be based not only on the desired packet traffic rates (which achieve optimality in the load distribution among the nodes), but also on the packet randomization affect of the routeing policy considered.
Analysis of the self‐framing performance of mBnB line codes
Authors: Fair I. J. , Krzymien W. A. 
Published: July 2007

AbstractThis paper introduces a method to analyse the self‐framing properties of mBnB line codes. Consideration of correlation in the received bit stream yields a three step analysis technique: (1) evaluation of the probability that any n‐bit sequence in the received bit stream simulates a codeword, (2) development of a mathematical description of the desired lock entry and lock exit algorithms, and (3) the derivation and evaluation of equations which give framing performance for the frame search strategy of interest. Following discussion of the analysis technique, the framing performance of a 7B8B code is investigated. The results of the analysis are compared with those obtained by simulation to confirm the validity of the analysis technique.
Hierarchical NTSC compatible HDTV system architecture — A North American perspective
Authors: Toth Arpad G. , Tsinberg Mikhail , Rhodes Charles W. 
Published: July 2007

AbstractHigh definition television (HDTV) has become a major world‐wide event in the television arena. Since the early 1980s, when HDTV was first demonstrated by Japan, a number of alternative systems have emerged. These systems clearly reflect the business and political objectives of the particular countries or organizations. In North America, which is the largest single consumer market in the world, technical, business and political considerations are shaping the evolution of HDTV.This paper describes a possible advanced television (ATV) architecture for North America and defines its functional modules and corresponding interfaces. The developed model is recommended as a design tool for standardizing ATV in North America and analysing interrelationships of the functional modules on the economic basis. The paper proposes an ‘hierarchical’ ATV emission system with full NTSC compatibility and HDTV quality. Solutions are recommended for terrestrial broadcast, CATV and satellite. This work describes a total systems approach to HDTV called HDS‐NA (high definition system for North America). The two emission signals of HDS‐NA: HDMAC‐60 and HDNTSC are characterized. RF alternatives for the terrestrial broadcast of HDTV are also discussed.
A broadband switching experiment
Authors: Briley B. E. , Tokar J. V. 
Published: July 2007

AbstractA broadband switching experiment was presented at the ISS'87 and Telecom'87 conferences in Phoenix, Arizona, and Geneva, Switzerland, respectively and at the March 1988 Fair in Hanover, West Germany. This experiment was significant in that it illustrated techniques for switching broadband signals with a wide range of frequencies, formats and ultimate purposes. In particular, simultaneous switching (within the same switch fabric) of 30 MHz PFM, 45 Mb/s PCM, and 140 Mb/s PCM was demonstrated. These signals carried full‐motion, full‐colour NTSC video for desk‐to‐desk video teleconferencing, off‐the‐air broadcast video programming, and surveillance camera video. They also carried RGB video, digitized stored video images, and computer‐computer communications. Software features afforded a friendly human interface, allowing multiple, flexible service capabilities. Further, the experimental system, when deployed in Phoenix, demonstrated control of its capabilities via a narrowband ISDN link to an optically remoted 5ESS® switch module one km distant, which homed on a 5ESS host switch about 32 km further away. The technologies employed in the switch and the surrounding equipment are detailed, and the significance of this experiment relative to the broadband ISDN (BISDN) thinking is discussed.
A broadband central office for ATM
Authors: De Prycker M. , Bauwens J. 
Published: July 2007

AbstractRecently, a growing interest has been shown towards fast packet switching, ATD (asynchronous time division), or the more general term ATM (asynchronous transfer mode) in a number of companies and organizations such as CCITT and RACE. In Belgium a broadband experiment is planned using this technique. This paper focuses its attention on the central office (switching exchange).This exchange is a multistage network constructed with independent switching elements based on the self‐routing principle. The load control in the exchange is provided by a static load control mechanism applied to the logical connections granted on these links. Simulation results show that this load control mechanism can work perfectly if used in the proper environment.
World‐wide standardization of broadband ISDN
Authors: Byrne W. R. , Papanicolaou A. , Ransom M. N. 
Published: July 2007

AbstractA growing market demand for high‐performance voice, data, image and video networks, coupled with advances in high‐speed technologies has heightened interest in broadband ISDN (BISDN) throughout the world. Network providers, equipment manufacturers and standards bodies are working jointly to accelerate the definition of BISDN interfaces in anticipation of emerging market opportunities. BISDN is being designed as the foundation upon which to implement very flexible, high‐bandwidth, high‐performance networks. A multiplexing concept called asynchronous transfer mode (ATM), which can offer bandwidth on demand at rates exceeding 150 Mb/s, high‐speed packet switching, and an efficient protocol which adapts existing information streams into the ATM format are key attributes of the emerging BISDN network standards. This paper reviews the motivations behind BISDN, explains its key attributes and challenges and discusses possible strategies for evolving today's network toward BISDN.
Experimentation on asynchronous switching techniques for broadband ISDN
Authors: Melen R. , Giorcelli S. , Garetti E. , Demichelis C. , Perardi F. 
Published: July 2007

AbstractThis paper deals with a proposed implementation exploiting the new asynchronous transfer mode (ATM) multiplexing and switching techniques. In particular, the basic architectural and functional choices are outlined and various aspects are examined regarding the implementation of a switching arrangement using ATM switching techniques, giving some indication about its hardware and software architecture and the foreseeable system performance.
An ATM self‐routeing switch architecture
Authors: Imagawa Hitoshi , Urushidani Shigeo , Hagishima Koichi 
Published: July 2007

AbstractThis paper describes a new ATM self‐routeing switch architecture for integrated voice, video and data communications. The proposed switch consists of multi‐stage circulated shift registers and output buffers and uses the difference between incoming and outgoing line numbers as a routeing header. Every cell with a routeing header is easily, routed to its destination line with no contention in the switch. Point‐to‐multipoint connections can also be provided without additional complicated hardware. The routeing algorithm, switching mechanism and applications of the proposed switch are discussed.
Integrated BISDN access connection
Authors: Nilsson Gunnar , Westin Tommy 
Published: July 2007

AbstractThe broadband ISDN (BISDN) or integrated broadband communication (IBC) customer access connection (CAC) must meet a wide variety of technical and economic requirements in order to be competitive with dedicated network accesses and cope with the evolution of future services. Many proposals for broadband implementations are based on various service scenarios. Such scenarios may very well be applicable to certain user categories or at certain points in time. The CAC to be defined, however, has not to be based ononesuch scenario–but has to be able efficiently to support all the varying and evolving customer needs during a long period of time. In this paper the requirements are analysed and a CAC system concept fulfilling the basic requirements is put forward bearing in mind the interaction with relevant basic technology. A step‐by‐step evolution scenario for the BISDN/IBC network with emphasis on the CAC system introduction is outlined and finally some standardization issues are highlighted.
Fibre backbone for cable TV using multi‐channel am video trunking
Authors: Chiddix James A. 
Published: July 2007

AbstractThis paper updates a scenario for the evolutionary integration of optical fibre transmission technology into existing cable television networks first presented in 1988. The resulting ‘fibre backbone’ yields a hybrid fibre/coaxial network with significantly better reliability and transmission quality than present systems. System and electro‐optical component advances in the last year are reviewed, and the merits of various modulation techniques are examined. The fibre backbone approach emphasizes continuing the broadband delivery of a large number of video signals to the consumer.
Multiservice CATV—from the viewpoint of the IBCN
Authors: Stefler S. 
Published: July 2007

AbstractIn countries where basic telecommunication services cannot satisfy all demands, as in Hungary and some other countries, the function of CATV may be different from that in the developed countries. While maintaining the primary, program distribution function it is expedient to use the cable TV as a local, autonomous data network too. From this viewpoint the up‐to‐date CATV network is a forerunner of the integrated broadband communication networks (IBCNs). Surveying these possibilities, and their economical implementation, is in the interest of many telecommunications administrations. The Research Institute of the Hungarian PTT (the PKI) has for some time been dealing with the multi‐purpose application possibilities of cable TV systems too. In the framework of this research work, PKI has recently established an experimental cable TV network which is suitable for examining other functions as well.
Remarks on standard fibre‐optic LANs
Authors: Beale N. C. L. 
Published: July 2007

AbstractThis paper explains the importance of standard fibre‐optic LANs, and gives an overview of the state of development of the main emerging fibre‐optic LAN standards. Fibre‐optic enhancements to 802·3, 802·4 and 802·5 are discussed, as well as FDDI and FDDI‐2. A brief mention is made of 802·6 and SONET, which are not LANs but are relevant to the discussion. The need for a rational cabling infrastructure is mentioned, as is the need for conformance tests. Some of the practical reasons why it makes sense to have fibre available at the end stations are discussed.
QAM and QPRS digital broadband cable systems
Authors: Sreenath K. , Feher Kamilo , Sasase Iwao 
Published: July 2007

AbstractThe performance of high‐level modulation schemes in non‐linear broadband digital communication systems is investigated. The tolerance of 16‐, 64‐, 256‐QAM and 49‐, 225‐QPRS schemes to these non‐linearities is given in terms of their phase margins. Our research results show that high level QAM schemes are less sensitive to non‐linearities when operated in offset mode. Comparison of non‐linearly amplified broadband QAM and QPRS schemes reveals that QPRS schemes need less carrier‐to‐noise ratio (CNR) than corresponding QAM schemes for identical operating conditions. Also, when the non‐linearities are not severe, the degradation in performance is controlled by AM/PM characteristic of the broadband amplifier.
A BISDN customer access architecture optimized in relation to network implementation technology
Authors: Trondoli Alberto , Vago Gian Angelo 
Published: July 2007

AbstractThis paper aims at identifying an architecture model for a fibre‐optic‐based customer access network optimized at the minimum cost for the implementation technology and passive components inserted between the distribution centre and the subscriber premises. The optimization has been carried out on the basis of technical and economic considerations by taking into account the technology and market trends foreseen in this field. Moreover, a prediction of the cost reduction trend in the short‐and medium‐term scenario (up to 1995) has been derived for both the various passive components and the overall network implementation costs.
ATM switches—basic architectures and their performance
Authors: Rathgeb Erwin P. , Theimer Thomas H. , Huber Manfred N. 
Published: July 2007

AbstractThe prospect of a broadband ISDN based on the ATM principle has stimulated the development of new, high‐performance switching node architectures. In this paper different options for the switching networks used in such a node will be discussed in some detail. First, some generic architectures for the individual switching elements will be presented including the aspects of buffering and collision resolution, followed by a short classification of different types of switching networks and some performance figures for delta networks, a class of multi‐stage, single‐path interconnection networks. In the last section, the sensitivity of the performance results with respect to the traffic assumptions will be discussed.
A multistage ATM switch with interstage buffers
Authors: Kim Hyong Sok , Leon‐Garcia Alberto 
Published: July 2007

AbstractAsynchronous transfer mode (ATM) is the transport technique for the broadband ISDN recommended by CCITT (I.121). Many switches have been proposed to accommodate the ATM that requires fast packet switching capability.1‐8 The proposed switches for the broadband ISDN can be classified as being of input queueing or output queueing type. Those of the input queueing type have a throughput performance which is approximately 58 per cent that of the output queueing type. However, output queueing networks require larger amounts of hardware than input queueing networks. In this paper, we propose a new multistage switch with internal buffering that approaches a maximum throughput of 100 per cent as the buffering is increased. The switch is capable of broadcasting and self‐routeing. It consists of two switching planes which consist of packet processors, 2 x 2 switching elements, distributors and buffers located between stages and in the output ports. The internal data rate of the proposed switch is the same as that of the arriving information stream. In this sense, the switch does not require speed‐up. The switch has log2 N stages that forward packets in a store‐and‐forward fashion, thus incurring a latency of log2 N time periods. Performance analysis shows that the additional delay is small.
A three‐stage architecture for very large packet switches
Authors: Liew Soung C. , Lu Kevin W. 
Published: July 2007

AbstractThis paper proposes a three‐stage broadband packet switch architecture with more than 16,000 ports for a future central office. The switch is constructed by interconnecting many independent switch modules of small size which can be implemented using modifications of various well‐studied switch fabric designs. Channel grouping is used to provide multiple paths for each input‐output pair in order to decrease delay and increase throughput. We show that, for a given size, switch modules with channel grouping are simpler to realize than those without channel grouping. A datagram packet routeing approach is adopted in order to avoid table look‐up that would be required by virtual‐circuit routeing. Ways of preserving the sequence integrity of packets under this situation are presented. Performance analyses show that a 32,768 x 32,768 switch with acceptable performance can be constructed based on switch fabrics of no more than 128 ports.
Development of murine hepatic sinusoidal endothelial cells characterized by the expression of hyaluronan receptors
Authors: Nonaka Hidenori , Tanaka Minoru , Suzuki Kaori , Miyajima Atsushi 
Published: July 2007

AbstractEndothelial cells (ECs) display distinct structural and functional characteristics depending on the tissue and developmental stage; however, the development of tissue‐specific ECs remains poorly understood. Here, we describe the development of hepatic sinusoids in mice based on the expression of hyaluronan receptors Stab2 and Lyve‐1. Flk‐1+ cells in and around the liver bud begin to express Stab2 at embryonic day (E) 9.5, before the formation of vascular lumen. Hepatic sinusoidal endothelial cells (HSECs) begin to express Lyve‐1 at E10.5, and both markers continue to be expressed in HSECs thereafter. Although HSECs and lymphatic ECs (LECs) are known to share functional and phenotypic characteristics, we clearly show that HSECs can be distinguished from LECs by the expression of molecular markers and higher endocytotic activity. Our results provide new insight into the development of tissue‐specific ECs and phenotypic criteria to distinguish HSECs from other types of ECs, including LECs. Developmental Dynamics 236:2258–2267, 2007. © 2007 Wiley‐Liss, Inc.
Analysis and synthesis of continuous‐time hysteretic neural networks
Authors: Jin'no Kenya , Saito Toshimichi 
Published: July 2007

AbstractIn this article the authors propose a continuous‐time neural network which includes bipolar hysteretic elements. They then consider the problem of synthesis in order to satisfy the following conditions: I) the system has no oscillating solutions; II) any desired patterns are stored as stable output vectors; and III) the total number of false stable output vectors is made as small as possible. The authors then prove a sufficient condition for I) and the necessary and sufficient conditions for II). Based on these results, they propose a synthesis procedure which is also effective for III). The domain of attraction of stable outputs may be easily calculated using a fast algorithm using exact solutions. The efficiency of the procedure is confirmed through experimental results.
Several properties of permissive feedbacks in petri nets with external input places
Authors: Takai Shigemasa , Kodama Shinzo , Ushio Toshimitsu 
Published: July 2007

AbstractThis paper considers the controlled discrete event systems modeled by Petri nets with external input places. A maximal element in the set of permissive feedbacks is called a maximally permissive feedback. First, a simpler condition is derived for its unique existence which does not require constructing the set of permissive feedbacks.Next, a necessary and sufficient condition is derived for the reachable set under the unique maximally permissive feedback to be equal to the set of markings which satisfy the given predicate. Moreover, synthesis of the unique maximally permissive feedback is demonstrated for a simple manufacturing system.
II‐cascade wave digital filters that have zero sensitivity at each matching point and realize arbitrary transfer functions
Authors: Ishiwata Shunichi , Nishihara Akinori , Fujii Nobuo 
Published: July 2007

AbstractThe circuit with zero sensitivity at the matching points is desirable in the sense that a very low sensitivity can be expected in the passband. It should also be noted that the wave digital filter (WDF) with a II‐cascade structure has the advantage that the sensitivity in the stopband is lower than WDF with a T‐cascade structure. However, the synthesis method has not been known for WDF with a II‐cascade structure with the zero amplitude sensitivity at the matching points which can realize an arbitrary transfer function. This paper is an attempt to realize such a WDF.First, it is shown what type of sections should be used as the reference section of a doubly resistor‐terminated reactance filter. The two terminating resistances are set equal to avoid the situation where the sensitivity at the matching point turns out to be nonzero because of the effect of the terminating resistance ratio. Then the replacement of the multiplier is shown so that the forementioned state is maintained, even if the multiplier coefficients are quantized.It is shown that WDF exists corresponding to each section, where the forementioned replacement can be applied and the structural boundedness is retained even after the coefficients are quantized. As a result, it is shown that WDF actually exists with a II‐cascade structure with the zero amplitude sensitivity at the matching points which can realize an arbitrary transfer function.
Relation between generalized radial basis function (GRBF) networks and neural networks
Authors: Miyazaki Akio , Yamada Tsuyoshi 
Published: July 2007

AbstractThe problem of learning an input‐output mapping from a given set of samples can be handled by applying the theory of approximation, e.g., the spline approximation and regularization. It is well known that by formulating this kind of learning problem based on the regularization theory, generalized radial basis function (GRBF) networks are derived.The GRBF network has a three‐layered structure (input layer–intermediate layer–output layer). This suggests that the network is related closely to the multilayer neural network.This paper discusses the relation between the GRBF network and the neural network, and it is shown that the three‐layered neural network can be derived approximately from the GRBF network using the projection transform and the inverse projection transform. Based on this result, a construction method for the neural network is presented and the method is applied to the pattern class discrimination problem.