bluuebunny/crossref_metadata_2025_split huggingface dataset:
A passive network termination for BISDN optical subscriber lines
Authors: Liberg Øyvind 
Published: July 2007

AbstractConsiderable cost saving and overall simplification can be achieved if the protocol for the access digital section is made identical to the one at the T interface. The network termination (NT1) may then be realized as a passive device, such as a simple connector. All active functions associated with the NT1 can then be performed on a time‐shared basis from the premises of the network provider. This scheme obviates the need for remote power feeding and activation mechanisms of the NT1. The time sharing of active functions, such as optical time domain reflectometry (OTDR) for supervision of the physical conditions of the lines, allows a substantial cost reduction of the subscriber access. It is shown that this technique yields a more efficient maintenance scheme than that afforded by an active NT1, resulting in a cost saving also in the long term. Ways of implementing the passive NT1 are discussed, and also its position in the evolution of passive optical networks (PON) towards BISDN.
OAM mechanisms for BISDN UNI and access networks
Authors: Uno Hiroshi , Maeda Youichi , Kanayama Yukiharu 
Published: July 2007

AbstractThis paper clarifies operation and maintenance (OAM) requirements for broadband integrated services digital network (BISDN) customer access systems including user‐network interface (UNI), and proposes basic OAM mechanisms. Access networks employ a logical networking architecture based on the asynchronous transfer mode (ATM) virtual path (VP) concept to provide all services efficiently, economically. Services are independent of the network's physical configuration. Thus, OAM functions for the access network are required to support physical and ATM layer capabilities. UNI physical performance and failure information flows to ensure user service quality are described. A fault localization mechanism is introduced that determines whether the failure lies on the network provider side or customer side. It uses failure information flows and loop back testing at the network terminator 1 (NT1). As connection‐related virtual path connection (VPC) availability indication is necessary for user‐to‐network applications and user‐to‐user applications, two alternative VPC‐related availability indication mechanisms are studied. Furthermore, basic performance monitoring mechanisms for ATM layer are described.
Intelligence in ATM terminals
Authors: Hellemans Patrick , Decuypere Hubert 
Published: July 2007

AbstractIn this paper we propose to migrate the intelligence for telecommunication services from the network into the terminals. In the first three sections we elaborate on the approach taken. The descending cost of processing equipment and the increased flexibility offered by ATM networks open new perspectives for the terminal business. In addition, only limited services will be offered by early ATM networks. Terminal‐based intelligence may overcome this initial gap. The physical configuration of such a terminal is presented in Section 4. In Section 5 the functional configuration of the terminal is proposed. The control module realizes a generic platform for the execution of telecommunication applications. This platform gives access both to local peripherals and to the telecommunication services offered by the network. The top layer consists of the telecommunication applications. In Section 6 a number of these applications are discussed. The remote execution application is of special interest since it gives remote access to telecommunication applications hosted on other IATs, so enlarging the capabilities of the local IAT.
A simple detector for trellis‐coded PSK mobile radio systems
Authors: Elnoubi Said , Youssef El‐Sayed , Helal Khaled 
Published: July 2007

AbstractA simple detector for a trellis‐coded PSK mobile radio system is proposed. A precoder is added to the regular TC‐PSK modulator before convolution coding, and a simple one‐bit differential detector is used in the receiver. The decision is made symbol by symbol based on the output samples. The bit error rate of this system is evaluated in fast Rayleigh fading characterizing mobile radio channels by numerical integration.
An optimal policy for competitive processing of high‐ and low‐priority arrivals
Authors: Delic Hakan , Papantoni‐Kazakos P. 
Published: July 2007

AbstractWe consider two mutually independent traffic streams whose arrivals are stored in an infinite capacity buffer. The two arrival traffics are modelled by renewal processes and are competing for service by a single processor, where one of the processes requires a strict upper bound on the total delay per arrival. It is assumed that the processing per arrival, for both processes, is a constant; the value of this constant is different for each of the two traffic streams.Given the above model, we consider policies that operate in a non‐interruptive mode. We first find the optimal scheduling policy, which attains throughput one and minimizes the expected delays of both traffic streams. The delays induced by the latter policy are analysed via a methodology based on the regenerative theorem. The theoretical results are supported by numerical examples.
Integration of interactive and distribution services: Impact on the network architecture and signalling
Authors: de Prycker M. , Verhoeyen M. , Decuypere H. 
Published: July 2007

AbstractThe integration of interactive and distribution services has an impact on both the architecture of the network and the signalling protocols. A configuration where both services are offered via ATM is discussed here. For multimedia services a layered service model is described. The impact of this layered model on the signalling is explained.
A shared‐memory virtual channel queue for ATM broadband terminal adaptors
Authors: Chao H. Jonathan , Smith Donald E. 
Published: July 2007

AbstractIn order to take advantage of the low entry cost of the future public ATM (asynchronous transfer mode) network with shared facilities, it is highly desirable to interconnect different hosts and local area networks (LANs) to the ATM network. The interface between the computer hosts or LANs and the ATM network, commonly called a broadband terminal adaptor (BTA), provides the necessary format conversion for the data packets and the ATM cells. It is conceivable that multiple packets from different virtual channels are interleaved as they arrive at the receive‐end BTA. The BTA must have a sufficiently large buffer, called a virtual channel queue (VCQ), to temporarily store the partially received packets. Once a complete packet has been received, it is forwarded to the host or LAN. Whenever the buffer fills with all incomplete packets, a packet must be discarded to make room for others. In this paper, we first study, through computer simulations, the buffer size requirement of a shared‐memory VCQ for different numbers of virtual channels at various packet loss probabilities. We then present two different implementation architectures for the shared‐memory VCQ, and compare their hardware complexity. The second architecture with linked‐queue approach, adopted in our work, requires less buffer and has better scalability to accommodate a large number of virtual channels. Various possible error conditions, such as cell losses in the ATM network and the VCQ buffer overflow, are considered. Corresponding solutions are proposed and included in the VCQ designs.
A hybrid approach to the transmission of telephony over a passive optical network
Authors: Mudhar Richard 
Published: July 2007

AbstractPassive optical networks (PONs) are attractive for the provision of telephony via optical fibre in the local loop, and have generally tended to concentrate on the use of time‐division multiple access for transmission. This paper describes a hybrid transmission method using sub‐carrier multiplexing (SCM) and time division multiplexing (TDM) which seeks to reduce the overall complexity of the system, thereby lowering costs.
Bandwidth allocation and selective discarding for variable bit rate video and bursty data calls in ATM networks
Authors: Decina Maurizio , Toniatti Tiziana 
Published: July 2007

AbstractCongestion control mechanisms are required in ATM networks to fairly and efficiently allocate network resources to the various service types. Bandwidth allocation is a preventive control mechanism. On the basis of the traffic description given by the source, of the traffic load along the connection route and of the cell performance requirements, this mechanism gives a criterion to accept or reject a virtual connection request. A bandwidth called ‘equivalent bandwidth’ is allocated in order to ensure the cell transport objectives.This paper proposes a definition of equivalent bandwidth for stream, bursty data and variable bit rate video (VBRV) sources. The equivalent bandwidth values are evaluated by simulation considering both homogeneous and heterogeneous sources. In the heterogeneous mixes with different cell loss probability requirements the selective discarding mechanism permits a more efficient utilization of the network resources.
Performance of M‐QAM modulations for indoor radio communications with combined diversity and equalization techniques
Authors: Casadevall Fernando J. , Valdovinos Antonio 
Published: July 2007

AbstractDigital indoor radio communications systems have become an attractive proposal as they could provide the user high quality voice and low rate data services with total mobility. However, indoor communications are affected by multipath propagation that restricts their application imposing an upper limit on the system data rate. To overcome this drawback diversity and channel equalization could be considered. In this paper the performances of 4, 16 and 64‐QAM modulations in a radio communications indoor environment are presented. The results show that a system without protection has very limited performance. Diversity techniques are efficient when the radio channel can be assumed to be non‐selective. For systems operating in selective fading channels joint equalization and diversity techniques are necessary to fight the degrading effect introduced by the channel. Moreover, if correlation between the two diversity channels is taken into account, the system performances remain almost unchanged, assuming that the correlation coefficient between the two diversity branches is lower than 0.6 to 0.7 approximately.
A codec for HDTV signal transmission through terrestrial and satellite digital links
Authors: Cominetti Mario , Molo Francesco 
Published: July 2007

AbstractA codec for digital transmission of HDTV is described. The bit‐rate compression algorithm is based on advanced techniques such as spatial discrete cosine transform (DCT), temporal differential PCM (DPCM), variable length coding. The codec is designed to operate with both the interlaced studio systems 1125/60 and 1250/50, and, thanks to the inherent flexibility of the packet structure, a wide range of line bit‐rates can be used as a compromise between video quality and bit‐rate constraints of the digital transmission link. The flexibility of the HDTV codec is highlightened through examples of applications over satellite digital links in practical situations.
HDMAC encoder—first generation: Experience and applications
Authors: Bathe Paul 
Published: July 2007

AbstractThis article deals with the first generation of HDMAC ENCODER equipment. Methods for bandwidth reduction, processing to obtain a compatible picture and the test concept for the encoder will be presented. In addition, the 140‐Mbit/s transmission system for HDMAC will be described and future methods for transmission and application of HDMAC illustrated.
Performance evaluation of error recovery schemes in high‐speed networks
Authors: Nilsson Arne A. , Lai Fuyung 
Published: July 2007

AbstractError control in high speed communication networks is usually applied either as a link‐by‐link scheme or an end‐to‐end scheme. The performance of such schemes is analyzed in this paper. The impact of errors due to transmission errors as well as dropped packets due to buffer overflow is incorporated in the models.
Design of a non‐blocking shared‐memory copy network for ATM
Authors: Bianchini Ronald P. , Kim Hyong S. 
Published: July 2007

AbstractThe design of a copy network is presented for use in an ATM (asynchronous transfer mode) switch supporting BISDN (broadband integrated services digital network) traffic. Inherent traffic characteristics of BISDN services require ATM switches to handle bursty traffic with multicast connections. In typical ATM switch designs a copy network is used to replicate multicast cells before being forwarded to a point‐to‐point routeing network. In such designs, a single multicast cell enters the switch and is replicated once for each multicast connection. Each copy is forwarded to the routeing network with a unique destination address and is routed to the appropriate output port. Non‐blocking copy networks permit multiple cells to be multicasted at once, up to the number of outputs of the copy network. Another critical feature of ATM switch design is the location of buffers for the temporary storage of transmitted cells. Buffering is required when multiple cells require a common switch resource for transmission. Typically, one cell is granted the resource and is transmitted while the remaining cells are buffered. Current switch designs associate discrete buffers with individual switch resources. Discrete buffering is not efficient for bursty traffic as traffic bursts can overflow individual switch buffers and result in dropped cells, while other buffers are under‐used. A new non‐blocking copy network is presented in this paper with a shared‐memory input buffer. Blocked cells from any switch input are stored in a single shared input buffer. The copy network consists of three banyan networks and shared‐memory queues. The design is scalable for large numbers of inputs due to low hardware complexity, O (Nlog2N), and distributed operation and control. It is shown in a simulation study that a switch incorporating the shared‐memory copy network has increased throughput and lower buffer requirements to maintain low packet loss probability when compared to a switch with a discrete buffer copy network.
Novel algorithm for time division multiple access in broadband ISDN passive optical networks
Authors: Glade M. , Keller H. 
Published: July 2007

AbstractFor shared access to a broadband communication network using the asynchronous transfer mode (ATM) a passive optical network (PON) has previously been proposed. A novel algorithm to evaluate the time division multiple access (TDMA) protocol which controls the traffic from the various subscribers towards the shared access equipment (upstream direction) is proposed. It uses counters to estimate the moment of a data packet arrival at the subscriber side. By this ‘look‐ahead’ technique no extra upstream channels are needed to initiate the polling by the subscriber. The algorithm guarantees fair access for all subscribers and minimizes the necessary overhead. Both the maximum access delay and overhead may be readily calculated, and the obtained results were supported by numerical simulation. Applicability in the standard broadband network environment has been proved by hardware design simulation.
On the combined effect of DPSK modulation level and block coding on cellular capacity
Authors: Gejji Raghvendra R. 
Published: July 2007

AbstractIn this paper we consider how closely the theoretical limiting cellular capacity, given recently as a function of CIR (carier‐to‐interference ratio) by Gejji, may be achieved by commonly used modulation and coding schemes such as DPSK and BCH coding. Specifically, we consider the variation in channels/cell with CIR in the face of varying modulation level and block coding length. We also compare performance with the limit given recently. It is seen that the advantage of QPSK over 8PSK is reduced in the presence of coding compared to without coding. It is also seen that the ratio of actual capacity to the limiting value is constant over a range of CIR values.
Efficient algorithms for multiple destinations routeing
Authors: Leung Yiu‐Wing , Yum Tak‐Shing 
Published: July 2007

AbstractA number of important problems in computers and telecommunications, such as distributed databases and multipoint multimedia conferencing, all require the solution of a generic problem called multiple destinations routeing (MDR). In this paper, we formulate the MDR problem as a zero‐one integer programming problem and propose a technique to reduce the computation required for the optimum solution. Three heuristics are designed for large MDR problems. Heuristic A can offer different degrees of optimality with different amounts of time allowed for the solution. Heuristic B is a modification of Prim's algorithm for the minimum spanning tree. It gives a fairly good solution with very little computation. Heuristic C is based on Heuristic B and is for minimizing the number of edges in the multicast tree (i.e. assuming that all edge weights are the same). It always gives a better solution than Heuristic B. Simulation on two example networks shows that Heuristics A and C always give better solutions (or lower cost connection paths) than the improved RS algorithm, which has up to now been the best heuristic.
Deterministic access protocols for packet radio networks
Authors: Paschos S. A. , Anagnostou M. E. , Afrati F. N. 
Published: July 2007

AbstractIn this paper, multiple‐phase deterministic protocols for packet radio networks are introduced and analysed. Two modes of information transfer are considered, namely (a) broadcasting and (b) point‐to‐point transmission. We explore systematic ways of designing multiple‐phase protocols and apply them on Manhattan networks. The proposed protocols are studied primarily from the point of view of throughput efficiency. Delay analysis is also presented.
ATM—success or failure? Economic remarks on the introduction of broadband technology in Europe
Authors: Anstötz Karin 
Published: July 2007

AbstractThe introduction of ATM and broadband‐based equipment into the European market requires considerable capital investment. It will result in a structural technological change, affecting the competitiveness of the European economy. Successful introduction depends on how both ATM network equipment and broadband based end‐user equipment are brought onto the market. This paper focuses on economic benefits and anticipating marketing strategies, applicable in Europe with its specific, historically evolved structures. The price to pay for this ‘in‐sight information’ is leaving out a global comparison. Refraining from evaluation whether conditions are good or bad for Europe or other areas, the article explains what conditions can be found there recently and where are the chances and challenges right now.
Burstiness and resource management in ATM networks
Authors: Boyer Jacqueline , Dupuis Alain , Guillemin Fabrice 
Published: July 2007

AbstractNetworks based upon the asynchronous transfer mode (ATM) provide for high flexibility to cope with a wide range of applications, some of them producing highly sporadic traffic. Therefore, the problem of burstiness has become in the last few years a key issue for such networks. A basic question is how to dimension network buffers in the presence of bursty traffic? In this paper we investigate the concept of burstiness and its impact on resource management. In burstiness characterization encountered in the literature, special attention has been given to the squared coefficient of variation of inter‐arrival time Cv2 in a cell arrival process. In order to observe the impact of bursty traffic on a queue, we develop in the present paper a ‘bursty’ traffic model, namely the two‐stage hyper‐Bernoulli cell arrival process, HBP2, for short. We numerically solve the HBP2/D/1/K queue. We especially derive the rejection probability Ploss. Numerical results are then thoroughly studied and we discuss the relevance for burstiness characterization of Cv2 and peak to mean rate ratio B. We draw attention to the concept of local overload, i.e. when the arrival rate is greater than the server rate. This seems to be the most relevant phenomenon in the impact of a bursty traffic on a queue. These results are finally applied to the problem of resource management in ATM networks.
The zebrafish vitronectin receptor: Characterization of integrin αV and β3 expression patterns in early vertebrate development
Authors: Ablooglu Ararat J. , Kang Jian , Handin Robert I. , Traver David , Shattil Sanford J. 
Published: July 2007

AbstractαVβ3 is a receptor for vitronectin and other extracellular matrix ligands, and it has been implicated in angiogenesis and osteoclast function in mammals. We have cloned full‐length cDNAs of zebrafish integrin αV (itgαV), and two paralogous zebrafish β3 integrins (itgβ3.1 and itgβ3.2). Whole‐mount in situ hybridization analysis revealed that αV and β3.1 share overlapping expression domains in apical ectodermal ridge, ventricular myocardium, hypothalamus, posterior tuberculum, medial tectal proliferation zone, and in the odontogenic field of the bilateral pharyngeal dentitions. In contrast to β3.1, β3.2 is transiently expressed throughout the developing embryo. In situ hybridization profiles and heterologous expression of proteins in tissue culture cells suggest that β3.1 is the major β3 paralog that associates with αV in zebrafish. Furthermore, when β3.1 expression profiles are compared to those of other potential αV partners (β1, β5, and β8), pharyngeal dentitions appear to represent a unique expression field for αV and β3.1. Developmental Dynamics 236:2268–2276, 2007. © 2007 Wiley‐Liss, Inc.
Testable design for cell‐based design ASICs and its application to VLSI image signal processor
Authors: Kawai Hiroyuki , Nakagawa Shin‐Ichi , Yoshimoto Masahiko , Horiba Yasutaka , Ogihara Takuji , Tada Akiharu 
Published: July 2007

AbstractThis paper proposes a testing method which provides an efficient test for the library macrocell built in a large‐scale and high‐speed application‐specific IC (ASIC) of a cell‐based design, especially in the parallel processor for the image processing VLSI. The proposed method consists of the test pattern assembly tool and the testability design for the efficient test. The test pattern is assembled automatically from the test pattern library of the macrocell and the access sequence description, which describes the access procedure from the external pins of the LSI and/or scan registers to the input/output pins of the macrocell built in the LSI.By the foregoing description, the access to the macrocell through the sequential circuit also is possible. With regard to the design for testability, the clock control method, the bus driver circuit, and the test mode control method are newly devised and are combined with the system bus and the scan register.The proposed method is applied to the high‐speed image processing VLSI. The test patterns for four library macrocells in the LSI (two RAMs, multiplier, and PLA) were assembled in one day. The proposed method can also be applied to the user developed macrocell which is utilized iteratively in an LSI. The increase of the number of transistors and the transistor area is suppressed to 3.1 percent (in regard to logic unit) and 0.6 percent (in regard to the whole chip area), respectively. It is verified that there is little decrease of the operational speed in the system operation and does not affect the high‐speed image processing.