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Selected Areas in Communications, IEEE Journal on

Issue 2 • Date Feb 1991

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Displaying Results 1 - 20 of 20
  • CCITT work in teletraffic engineering

    Publication Year: 1991 , Page(s): 131 - 134
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (372 KB)  

    The advantages and drawbacks of standardization in TTE (teletraffic engineering) are examined. It is pointed out that the TTE recommendations of CCITT are intended to be international standards. Unlike signaling systems, interfaces, or protocols, the necessity for standardization in this area is not self-evident. However, standardization of grade of service (GOS) definitions, values, and relevant reference conditions seems to be necessary. Support for engineering methods also offers advantages. TTE-related activities in different CCITT study groups try to satisfy many often contradictory demands. Trends in telecommunications strongly support the view that concentration of TTE studies in CCITT would be desirable View full abstract»

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  • A study of slot reuse in dual bus multiple access networks

    Publication Year: 1991 , Page(s): 248 - 256
    Cited by:  Papers (35)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (772 KB)  

    In dual unidirectional bus networks, packets usually occupy fixed-length slots form the sending station to the end of the network. An erasure node is a specialized station which recognizes packets which have passed their destination stations and releases the slots for subsequent use. The authors derive the optimal locations for erasure nodes and show analytically, for uniform traffic, that only several erasure nodes are needed to achieve throughput close to twice the nominal network bandwidth. The results are tested by simulation of the DQDB (distributed queue dual bus) protocol, which demonstrates a realistic improvement of 40% with only three erasure nodes. Fair access among the stations is improved as well. The authors generalize the analytic results by providing an algorithm for determining the optimal erasure node locations and the throughput improvement, given any arbitrary traffic pattern. The application of this methodology to the related problem of bridged subnetworks is briefly discussed View full abstract»

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  • Packet switch engineering procedures when customer characteristics are uncertain

    Publication Year: 1991 , Page(s): 142 - 150
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (708 KB)  

    A method for packet-switch provisioning which accounts for the effects of uncertainty in estimating customer characteristics is demonstrated. The method models the traffic parameters of the customers as random variables. It is used to calculate the maximum number of customers that can be accommodated while controlling the probability that their traffic control is beyond the nominal capacity of the system. It is shown that, depending on the degree of uncertainty in estimating parameters for the arrival process, the application of the method can have a substantial impact on the provisioning of the switch. Examples in which the effects of uncertainty on engineering are quantified are given View full abstract»

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  • On the performance of a circuit switched link with priorities

    Publication Year: 1991 , Page(s): 212 - 219
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (532 KB)  

    The author studies links carrying calls of distinct classes subject to different degrees of access restriction, e.g. by means of some trunk reservation device. Calls are accepted at random with the probability depending on the class of the call and the load on the link at the arrival instant. Assuming negative exponentially distributed holding times, the author develops a model that allows the computation of the steady-state loss probability, moments of the blocking periods, time-dependent probability of loss, and moments of overflow intervals for each class. Both Poissonian and peaked arrivals, the latter ones modeled by Markov-modulated Poisson processes, are considered. Efficient numerical techniques are described, and a numerical example, including comparisons to simulations, is given View full abstract»

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  • An analytic multiservice performance model for a digital link with a wide class of bandwidth reservation strategies

    Publication Year: 1991 , Page(s): 220 - 225
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (464 KB)  

    The author presents a study of a digital link that carries two traffic streams, each with its own bandwidth and service time requirements. The streams are modeled as two-state Markov-modulated Poisson processes. Thus, in addition to Poisson streams, one can study peaked streams or streams requiring a more complex specification. The author defines a flexible class of controls called extended bandwidth reservation (EXBR) that may be used to achieve a variety of objectives. EXBR includes as special cases most of the control strategies studied in the literature and thus provides a single platform to study different service integration alternatives. The model will predict the blocking performance of each service and the channel throughput. Numerical results illustrating the model are presented View full abstract»

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  • Analysis of command operation procedures (COPs) for reliable data transfer in the European Space Data Network

    Publication Year: 1991 , Page(s): 233 - 240
    Cited by:  Papers (1)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (684 KB)  

    Command operation procedures (COPs) are protocols operating in the transfer layer of the telecommand and telemetry architectures designed by the International Consultative Committee for Space Data Systems. The authors present an evaluation of virtual frame transmission times, throughput efficiency, buffer occupancy, and waiting times for the COP-2. COP-2 represents an ARQ-type (automatic repeat request) protocol with checkpointing that is comparable to the checkpoint mode protocol. A discrete two-class priority service model with random server interruptions is considered. The analysis is based on the concepts of level crossing analysis as defined in J.W. Cohen (1977) and J.G. Shanthikumar (1981). The results of this work will be used by the European Space Agency as design guidelines for the European Data Network View full abstract»

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  • Supporting network management with real-time traffic models

    Publication Year: 1991 , Page(s): 151 - 156
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (464 KB)  

    Real-time routing and flow control in circuit-switched networks is investigated. An algorithm which updates routing tables and flow-control parameters according to changing load conditions is derived. The network is described by means of stochastic difference equations. A control structure imposed by hardware requirements and realistic network status information patterns is considered. It is shown that the global objectives can be achieved by means of shortest-route algorithms with state-dependent route lengths. Implementation issues which are related to traffic estimation and prediction are discussed. The performance of a particular algorithm implementation is investigated by simulation View full abstract»

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  • Performance analysis of a LAN/WAN bridging architecture

    Publication Year: 1991 , Page(s): 265 - 270
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (548 KB)  

    The performance of local area networks (LANs) bridged through a virtual-circuit-based wide area network (WAN) is analyzed. The focus is on understanding end-to-end performance issues from an applications point of view. Results that can be used to traffic engineer the network to meet end-user service objectives on interactive response time and bulk data transfer throughput are derived. It is demonstrated that the use of a windowing protocol in the wide area network provides a robust control mechanism for regulating traffic and delivering high performance View full abstract»

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  • Oscillations and chaos in a flow model of a switching system

    Publication Year: 1991 , Page(s): 171 - 178
    Cited by:  Papers (13)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (644 KB)  

    Field data from digital switching systems in an access tandem environment indicate unexpectedly large queuing delays at moderate occupancies. It is shown that these delays are caused by an effect called traffic synchronization, which is the batching of a system's workload caused by interactions between the system and incident traffic. The authors develop a flow model to study this effect and show that a momentary overload can cause sustained oscillations in the system's queues. There are several steady-state modes of operation, and it is shown that for certain parameter ranges the system is chaotic. Such oscillatory behavior can significantly lower the real-time capacity of the switching system, and controls to limit the synchronization effect are suggested. These controls are incorporated into the flow model and analyzed. The results described are validated by numerical studies, simulations, and field data View full abstract»

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  • DCP, a distributed-control polling MAC protocol: specifications and comparison with DQDB

    Publication Year: 1991 , Page(s): 241 - 247
    Cited by:  Papers (7)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (628 KB)  

    The authors describe and analyze a novel MAC (media access control) protocol called distributed-control polling (DCP), which has been designed to bring together the most interesting features of distributed-control MAC protocols (e.g. distributed queue dual bus or DQDB) and centralized token-passing MAC protocols (e.g. FASNET, FDDI or fiber distributed data interface, and Express-ent). From the fully distributed MAC protocols. DCP acquires the ability to guarantee both a complete utilization of the medium capacity and an access delay of only a few slots at light loads. From the centralized token-passing MAC protocols, DCP inherits a more predictable and fair behavior at heavy loads. The basic ideas of the proposal are: a cycle for acquiring transmission rights, and a balancing function between reservations and empty slots. It is shown that DCP guarantees a complete utilization of the medium capacity and that its behavior at light loads is close to that of DQDB, while at heavy loads it approaches a polling system with limited service and zero reply interval View full abstract»

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  • Cyclic-service systems with probabilistically-limited service

    Publication Year: 1991 , Page(s): 185 - 193
    Cited by:  Papers (9)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (724 KB)  

    An asymmetric cyclic-service system with a probabilistically limited (PL) service policy is analyzed. In such a service policy, the maximum number of customers served at a queue during a server visit is determined by a probability which is independent of system states. Exhaustive, limited-k, and Bernoulli services are special cases of the PL policy. Customer service times and changeover times have general distribution. A numerical technique based on discrete Fourier transforms is proposed to solve for the queue-length distributions. Thus, the waiting and response-time distribution are obtained. A set of numerical examples is presented to validate the approach View full abstract»

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  • CITT E.700 recommendation series-a framework for traffic engineering of ISDN

    Publication Year: 1991 , Page(s): 135 - 141
    Cited by:  Papers (2)  |  Patents (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (704 KB)  

    Traffic engineering of ISDN (integrated services digital network) has become a key area of CCITT recommendations since 1985. The authors report on the first recommendations formalized in a dedicated series on ISDN traffic engineering, the CCITT E.700 series of recommendations. The authors also report on the ongoing work towards an extension of the series to cover integration of mobile services into ISDN, the E.750 series. Future directions related to such emerging issues as intelligent network services and broadband-ISDN/ATM (asynchronous transfer mode) are also reviewed View full abstract»

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  • Performance analysis of the timed token protocol of FDDI and FDDI-II

    Publication Year: 1991 , Page(s): 271 - 278
    Cited by:  Papers (26)  |  Patents (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (644 KB)  

    The performance behavior of an FDDI (fiber distributed data interface) system with synchronous traffic as well as an extended FDDI (FDDI-II) system with isochronous and asynchronous traffic is evaluated. Multiple asynchronous priorities are considered, one priority level at each station. an iterative algorithm to calculate the first two moments of the cycle (i.e. token rotation) time is presented, and the major system characteristics are derived from the analysis in terms of queue-length distributions and mean waiting times of the packets. Since the model considers queues with limited buffer size, loss probabilities of data packets can also be calculated. Some results obtained by the approximate analysis are discussed using example configuration, and the accuracy is validated by detailed computer simulations. The complexity and convergence behavior of the algorithm is studied, and it is shown that the algorithm converges very quickly View full abstract»

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  • An M/G/1 vacation model of an FDDI station

    Publication Year: 1991 , Page(s): 257 - 264
    Cited by:  Papers (21)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (660 KB)  

    The author defines and analyzes an M/G/1 vacation model that can be used to describe a single station in the fiber distributed data interface (FDDI). The M/G/1 model uses a service discipline called the exhaustive limited with limit variation discipline. According to this discipline, the server provides service until either the system is emptied or a randomly chosen limit of l frames has been served. The server then goes on a vacation before returning to service the queue again. The model can be used to gain insight into how the varying (timer-controlled) limit on the number of frames that can be transmitted during token visit at a station affects the mean waiting time in the timed-token protocol of FDDI. The analytical results of the M/G/1 vacation model are applied to an FDDI simulation example View full abstract»

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  • Multichannel circuit switching-performance evaluation of switching networks

    Publication Year: 1991 , Page(s): 226 - 232
    Cited by:  Papers (1)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (548 KB)  

    An approximate analytical method is presented for the estimation of the loss probability for single and multichannel calls in TST (time-space-time) switching networks. Two extended methods are described. The assumptions for the basic method are that: all occupation patterns of the two internal highways between a certain start and destination highway for a given number of occupied channels have the same probability, and that the state probabilities of the start and destination highway are given by a multidimensional Erlang distribution. Based on this method, the second approximation considers calls that are switched from start to destination highway. In a third method, the dependency of the states of all input and output highways is taken into account. The basic approximation has shown the best agreement with the simulation results. The other methods take into account additional properties of TST switching networks for single and multichannel connections. In order to keep the state space in a reasonable size, additional assumptions had to be used which impair the results significantly compared to the basic approximation method View full abstract»

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  • Performance analysis of a rate-control throttle where tokens and jobs queue

    Publication Year: 1991 , Page(s): 165 - 170
    Cited by:  Papers (28)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (564 KB)  

    A rate-control throttle is used for overload control in distributed switching systems and computer and communication networks. Typical implementations of the throttle have a token bank where an arriving job is blocked and rejected if the bank is empty of tokens. The author examines an expanded implementation where an arriving job queues in a finite buffer when the token bank is empty. It is shown that the steady-state throughput and blocking of jobs depends on the capacity of the job buffer and the capacity of the token bank only via the sum of the two capacities, not on their individual values. Thus, the job buffer per se is not needed to enhance the robustness of the throughput of the throttle to unknown exogenous job arrival rates. However, a job buffer (along with a token bank) with adjustable buffer capacities does have the potential to shape the departure process and to adapt between a delay control and a work-rejection control View full abstract»

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  • Limited waiting: an adaptive overload-control strategy for circuit switched networks

    Publication Year: 1991 , Page(s): 157 - 164
    Cited by:  Papers (2)  |  Patents (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (684 KB)  

    The authors present an adaptive control strategy for circuit-switched networks in which calls are permitted to wait for a limited time to be carried on a low-cost preferred route. The strategy uses network resources more efficiently than other conventional approaches, exhibiting lower blocking of calls under overload conditions. The proposed strategy is also adaptive in that, when there is little network congestion, there is no penalty for the policy, in contrast to other schemes in which improved performance under overload is achieved at the cost of degraded performance at lower bounds. The authors analyze an exactly solvable model and present simulation results for a more general network View full abstract»

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  • The M/G/1 queue with permanent customers

    Publication Year: 1991 , Page(s): 179 - 184
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (484 KB)  

    The authors examine an M/G/1 FCFS (first come, first served) queue with two types of customers: ordinary customers, who arrive according to a Poisson process, and permanent customers, who immediately return to the end of the queue after having received a service. The influence of the permanent customers on queue length and sojourn times of the Poisson customers is studied using results from queuing theory and from the theory of branching processes. In particular, it is shown that, when the service time distributions of the Poisson customers and all K permanent customers are negative exponential with identical means, the queue length and sojourn time distributions of the Poisson customers are the (K+1)-fold convolution of those for the case without permanent customers View full abstract»

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  • Analysis of a discrete multipriority queueing system involving a central shared processor serving many local queues

    Publication Year: 1991 , Page(s): 194 - 202
    Cited by:  Papers (12)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (788 KB)  

    The authors consider a multipriority queuing system which involves several distributed local queues and a central server which performs round-robin processor sharing (RRPS). This queuing model, referred to as multiqueue processor sharing (MPS), is an extension of Kleinrock's classical processor sharing model with generalization to multiple priorities and the addition of a buffer at each traffic source for each priority to buffer additional packets queued at that source. The authors present an exact analysis of the MPS model which leads to a closed-form result for the mean packet delay as a function of the packet length for each priority. It is demonstrated by simulation that the result obtained is applicable for accurately computing the average packet delay for a DQDB (distributed queue dual bus) subnetwork, given that stations transmitting on the same bus are not widely separated View full abstract»

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  • Characterizing the variability of arrival processes with indexes of dispersion

    Publication Year: 1991 , Page(s): 203 - 211
    Cited by:  Papers (50)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (840 KB)  

    The author proposes to characterize the burstiness of packet-arrival processes with indexes of dispersion for intervals and counts. These indexes, which are functions of the variance of intervals and counts, are relatively straightforward and can estimate and convey much more information than simpler indexes (such as the coefficient of variation) that are often used to describe burstiness quantitatively. The author defines and evaluates the indexes of dispersion for some of the simple analytical models that are frequently used to represent highly variable processes. The indexes for a number of measured point processes that were generated by workstations communicating to file servers over a local area network are also estimated. It is shown that nonstationary components in the measured packet-arrival data distort the shape of the indexes, and ways to handle nonstationary data are proposed. To show how to incorporate measures of variability into analytical models and to offer an example of how to model the measured packet-arrival processes, the author describes a fitting procedure based on the index of dispersion for counts for the Markov-modulated Poisson process View full abstract»

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Aims & Scope

IEEE Journal on Selected Areas in Communications focuses on all telecommunications, including telephone, telegraphy, facsimile, and point-to-point television, by electromagnetic propagation.

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Editor-in-Chief
Muriel Médard
MIT