Buffer occupancy of statistical multiplexers with periodic interchangeable traffic in ATM networks

In this paper we analyze the buffer occupancy in a statistical multiplexer in ATM networks for a special type of traffic, namely, periodic interchangeable (PI) traffic. Certain generalized Ballot theorem is applied to analyze the problem. Explicit formulas for the expected buffer occupancy are derived

Analysis of Buffer Starvation with Application to Objective QoE Optimization of Streaming Services

Our purpose in this paper is to characterize buffer starvations for streaming services. The buffer is modeled as an M/M/1 queue, plus the consideration of bursty arrivals. When the buffer is empty, the service restarts after a certain amount of packets are \emph{prefetched}. With this goal, we propose two approaches to obtain the \emph{exact distribution} of the number of buffer starvations, one of which is based on \emph{Ballot theorem}, and the other uses recursive equations. The Ballot theorem approach gives an explicit result. We extend this approach to the scenario with a constant playback rate using T\`{a}kacs Ballot theorem. The recursive approach, though not offering an explicit result, can obtain the distribution of starvations with non-independent and identically distributed (i.i.d.) arrival process in which an ON/OFF bursty arrival process is considered in this work. We further compute the starvation probability as a function of the amount of prefetched packets for a large number of files via a fluid analysis. Among many potential applications of starvation analysis, we show how to apply it to optimize the objective quality of experience (QoE) of media streaming, by exploiting the tradeoff between startup/rebuffering delay and starvations.Comment: 9 pages, 7 figures; IEEE Infocom 201

Analysis of jitter due to call-level fluctuations

In communication networks used by constant bit rate applications, call-level dynamics (i.e., entering and leaving calls) lead to fluctuations in the load, and therefore also fluctuations in the delay (jitter). By intentionally delaying the packets at the destination, one can transform the perturbed packet stream back into the original periodic stream; in other words: there is a trade off between jitter and delay, in that jitter can be removed at the expense of delay. As a consequence, for streaming applications for which the packet delay should remain below some predefined threshold, it is desirable that the jitter remains small. This paper presents a set of procedures to compute the jitter due to call-level variations. We onsider a network resource shared by a fluctuating set of constant bit rate applications (modelled as periodic sources). As a first step we study the call-level dynamics: supposing that a tagged call sees n0 calls when entering the system, then we compute the probability that at the end of its duration (consisting of, say, i packets) ni calls are present, of which n0,i stem from the original n0 calls. As a second step, we show how to compute the jitter, for given n0, ni, and n0,i; in this analysis generalized Ballot-problems have to be solved. We find an iterative exact solution to these, and explicit approximations and bounds. Then, as a final step, the (packet-level) results of the second step are weighed with the (call-level) probabilities of the first step, thus resulting in the probability distribution of the jitter experienced within the call duration. An explicit Gaussian approximation is proposed. Extensive numerical experiments validate the accuracy of the approximations and bound

Probabilistic Analysis of Buffer Starvation in Markovian Queues

International audienceOur purpose in this paper is to obtain the \emph{exact distribution} of the number of buffer starvations within a sequence of $N$ consecutive packet arrivals. The buffer is modeled as an M/M/1 queue. When the buffer is empty, the service restarts after a certain amount of packets are \emph{prefetched}. With this goal, we propose two approaches, one of which is based on \emph{Ballot theorem}, and the other uses recursive equations. The Ballot theorem approach gives an explicit solution, but at the cost of the high complexity order in certain circumstances. The recursive approach, though not offering an explicit result, needs fewer computations. We further propose a fluid analysis of starvation probability on the file level, given the distribution of file size and the traffic intensity. The starvation probabilities of this paper have many potential applications. We apply them to optimize the quality of experience (QoE) of media streaming service, by exploiting the tradeoff between the start-up delay and the starvation

Methods for evaluation packet delay distribution of ows using Expedited Forwarding PHB, Journal of Telecommunications and Information Technology, 2004, nr 2

The paper regards problem of providing statistical performance guarantees for real-time flows using Expedited Forwarding Per Hop Behavior (EF PHB) in IP Differentiated Services networks. Statistical approach to EF flows performance guarantees, based on calculation of probability that end-to-end packet delay is larger than certain value, allows larger network utilization than previously proposed deterministic approach. In the paper different methods of packet delay distribution evaluation are presented and compared. Considered cases comprise evaluation of delay distribution models for the core network and evaluation of end-to-end packet delay in the network consisted of edge node and chain of core nodes. Results obtained with aid of analytical models are compared with simulation results

A tandem queue with Lévy input: a new representation of the downstream queue length.

In this paper we present a new representation for the steady state distribution of the workload of the second queue in a two-node tandem network. It involves the difference of two suprema over two adjacent intervals. In case of spectrally-positive

Analytical models for the multiplexing of worst case traffic sources and their application to ATM traffic control.

Postprint (published version

Performance analysis of an asynchronous transfer mode multiplexer with Markov modulated inputs

Ankara : Department of Electrical and Electronics Engineering and the Institute of Engineering and Science of Bilkent University, 1993.Thesis (Ph.D.) -- Bilkent Iniversity, 1993.Includes bibliographical references leaves 108-113.Asynchronous Transfer Mode (ATM) networks have inputs which consist of superpositions of correlated cell streams. Markov modulated processes are commonly used to characterize this correlation. The first step through gaining an analytical insight in the performance issues of an ATM network is the analysis of a single channel. One objective of this study is the performance analysis of an ATM multiplexer whose input is a Markov modulated periodic arrival process. Based on the transient behavior of the nD/D/1 queue, we present an approximate method to compute the queue length distribution accurately. The method reduces to the solution of a linear differential equation with variable coefficients. Another general traffic model is the Markov Modulated Poisson Process (MMPP). We employ Pade approximations in transform domain for the deterministic service time distribution in an M MPP/D/1 queue so as to compute the distribution of the buffer occupancy. For both models, we also provide algorithms for analysis in the case of finite queue capacities and for computation of effective bandwidth.Akar, NailPh.D

Journal of Telecommunications and Information Technology, 2004, nr 2

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