摘要:

AbstractThis paper proposes and describes R‐net, a network with a new reservation access protocol that is very suitable for implementation with optical fibre in high speed local area networks. In the operation of R‐net, a framing structure with variable length is superimposed on the network bus to bound the network medium access delay which is a highly desirable feature for real time applications. As long as the frame length constraint is not violated, the performance of R‐net network is not limited by operating data rate, and the utilization can be set to unity by choosing the appropriate network parameters. The proposed network has the advantage of efficient throughput approaching unity for most practical configurations, bounded delay, and at normal load, the network protocol has fair access for all nodes and allows dynamic bandwidth allocation between the nodes connected to the network bus. A performance (delay and utilization) comparison between R‐net and Expressnet is also pr

ISSN:1047-9627    

DOI:10.1002/dac.4510050102

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractThis paper analyses different equalization, coding and signal constellation alternatives for the proposed high‐bit‐rate (800 kb/s) digital subscriber loop transmission interface. The simulation results presented in the paper demonstrate that bit rates above 1000 kb/s at acceptably low bit‐error rates (≤ 10−7) are feasible, if baseband transceivers with appropriate equalization and simple trellis coding are used. It is also shown that baseband transmission and Tomlinson precoding provide a significant performance advantage over bandpass transmission and decision‐feedback equalization, r

ISSN:1047-9627    

DOI:10.1002/dac.4510050103

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

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

ISSN:1047-9627    

DOI:10.1002/dac.4510050104

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractIn this paper, we present an approximation for the probability of cell loss of heterogeneous bursty traffic in broadband integrated packet networks based on the asynchronous transfer mode. The sources considered here alternate between active and silent periods and are characterized by their peak and average transmission rates. The cell loss probability is obtained by considering only the number of active sources at a given time and computing the amount of traffic that exceeds the link capacity. Since the amount of buffered excess traffic is not considered in this computation, this approximation is actually an upper bound of the cell loss probability. The numerical efficiency of this bound enables it to be used as a measure based on which robust and simple resource allocation strategies can be developed for bursty sources. Comparison of this bound with the simulation results has shown that the bound is close to the actual loss probabilities especially for large burst lengths and high utilizations.

ISSN:1047-9627    

DOI:10.1002/dac.4510050105

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractWhile static open loop rate controls may be adequate for handling continuous bit rate (CBR) traffic, relatively smooth data traffic, and relatively low speed bursty data traffic over broadband integrated networks, high speed bursty data sources need more dynamic controls. Burst level resource allocation is one such dynamic control. Potential benefits and other issues for burst level resource parameter negotiations for bursty data traffic over high speed wide area packet networks have been discussed earlier.1–6A detailed analysis of an adaptive buffer/window negotiation scheme for long file transfers using these concepts is presented in Reference 1. In this paper we discuss two burst level buffer/window negotiation schemes for short intermittent file transfers, focusing on the specific needs of such traffic streams. We develop closed network of queues models to reflect the behaviour of the proposed schemes. These models, while being simple, capture essential details of the control schemes. Under fairly general assumptions, the resulting network of queues is of product form and can be analysed using the mean value analysis. We use such an analysis to compare the proposed schemes and to determine appropriate sizes of trunk buffers to achieve the desired balance between bandwidth utilization and file transfer delay. The effects of other parameters on the performance of these schemes as well as on the buffer sizing rules are also discussed.Burst level (in‐call) parameter negotiation may be carried out by the end system with the network elements or by an interface system (access controller) with the broadband network elements. We discuss implications of this location as well as the needed protocol features. Finally, the service discrimination capabilities desired at the trunk controllers in switching nodes are briefly discus

ISSN:1047-9627    

DOI:10.1002/dac.4510050106

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractA closed form solution that yields the component shift required for the vector representation ofm‐sequences over GF(q2) in terms ofm‐sequences over GF(q2) is presented. Iterative application of this expression then enables the vctor representation ofm‐sequences over GF(q2m) in terms ofm‐sequences over GF(q). These vectorm‐seqeences can be used directly for the selection of frequencies in frequency hopped spread spectrum communicatio

ISSN:1047-9627    

DOI:10.1002/dac.4510050107

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

ISSN:1047-9627    

DOI:10.1002/dac.4510050108

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

ISSN:1047-9627    

DOI:10.1002/dac.4510050101

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY