Statistical multiplexing of multiple time-scale Markov streams

Caption title.Includes bibliographical references (p. 25-27).Supported by the Army Research Office. DAAL03-92-G-0115 Supported by a 1967 Natural Science and Engineering Council Fellowship form the Government of Canada.David N.C. Tse, Robert G. Gallager and John N. Tsitsiklis

The Statistical Analysis of the Live TV Bit Rate

This paper studies the statistical nature of TV channels streaming variable bit rate distribution and allocation. The goal of the paper is to derive the best-fit rate distribution to describe TV streaming bandwidth allocation, which can reveal traffic demands of users. Our analysis uses multiplexers channel bandwidth allocation (PID) data of 13 TV live channels. We apply 17 continuous and 3 discrete distributions to determine the best-fit distribution function for each individual channel and for the whole set of channels. We found that the generalized extreme distribution fitting most of our channels most precisely according to the Bayesian information criterion. By the same criterion tlocationscale distribution matches best for the whole system. We use these results to propose parameters for streaming server queuing model. Results are useful for streaming servers scheduling policy design process targeting to improve limited infrastructural resources, traffic engineering through dynamic routing at CDN, SDN

Optimal Operating Point in MIMO Channel for Delay-Sensitive and Bursty Traffic

Abstract — We consider a system with a bursty and delay-sensitive data source to be transmitted over a constant-rate MIMO channel with no CSI information at the transmitter. Given the diversity-multiplexing tradeoff region of the MIMO channel, we find the optimal multiplexing rate that optimizes the end-to-end loss probability. Based on the effective bandwidth model of the source, we present an analytical tradeoff between the error probability over the MIMO channel and the probability of delay violation. We illustrate the optimal operating points for i.i.d. sources and Markov-modulated sources and show the relation between source burstiness, delay bound, and optimal multiplexing rate. I

Asymptotic buffer overflow probabilities in multiclass multiplexers : part I : the GPS policy

Cover title.Includes bibliographical references (p. 34-37).Supported by a Presidential Young Investigators award. DDM-9158118 Matching funds from Draper Laboratory. Supported by ARO. DAAL-03-92-G-0115Dimitris Bertsimas, Ioannis Ch. Paschalidis, John N. Tsitsiklis

A review of connection admission control algorithms for ATM networks

The emergence of high-speed networks such as those with ATM integrates large numbers of services with a wide range of characteristics. Admission control is a prime instrument for controlling congestion in the network. As part of connection services to an ATM system, the Connection Admission Control (CAC) algorithm decides if another call or connection can be admitted to the Broadband Network. The main task of the CAC is to ensure that the broadband resources will not saturate or overflow within a very small probability. It limits the connections and guarantees Quality of Service for the new connection. The algorithm for connection admission is crucial in determining bandwidth utilisation efficiency. With statistical multiplexing more calls can be allocated on a network link, while still maintaining the Quality of Service specified by the connection with traffic parameters and type of service. A number of algorithms for admission control for Broadband Services with ATM Networks are described and compared for performance under different traffic loads. There is a general description of the ATM Network as an introduction. Issues to do with source distributions and traffic models are explored in Chapter 2. Chapter 3 provides an extensive presentation of the CAC algorithms for ATM Broadband Networks. The ideas about the Effective Bandwidth are reviewed in Chapter 4, and a different approach to admission control using online measurement is presented in Chapter 5. Chapter 6 has the numerical evaluation of four of the key algorithms, with simulations. Finally Chapter 7 has conclusions of the findings and explores some possibilities for further work

Statistical Multiplexing of Multiple Time-Scale Markov Streams

We study the problem of statistical multiplexing of cell streams that have correlations at multiple time-scales. Each stream is modeled by a singularly perturbed Markov-modulated process with some state transitions occurring much less frequently than others. One motivation of this model comes from variable-rate compressed video, where the fast time-scale dynamics may correspond to correlations between adjacent frames, while the slow time-scale dynamics may correspond to correlations within the same scene of a video sequence. We develop a set of !arge deviations results to estimate the buffer overflow probabilities in various asymptotic regimes in the buffer size, rare transition probabilities, and the number of streams. Using these results, we characterize the multiplexing gain in both the channel capacity and the buffering requirements and highlight the impact of the slow time-scale of the streams

Providing quality of service over high speed electronic and optical switches

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2003.Includes bibliographical references (leaves 235-239).This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.In a network, multiple links are interconnected by means of switches. A switch is a device with multiple input and output links, and its job is to move data from the input links to the output links. In this thesis, we focus on a number of fundamental issues concerning the quality of service provided by electronic and optical switches. We discuss various mechanisms that enable the support of quality of service requirements. In particular, we explore fundamental limitations of current high speed packet switches and develop new techniques and architectures that make possible the provision of certain service guarantees. We then study optical wavelength switches and illustrate how similar ideas can be applied in a manner consistent with the current state of optical switching technology. First, we focus on providing rate guarantees over packet switches. We develop a method called rate quantization which converts the set of desired rates into a certain discrete set such that the quality of service guarantees can be greatly improved with a small resource speedup. Moreover, quantization simplifies rate provisioning for dynamically changing traffic demands since it allows service opportunities for different input output link pairs to be scheduled with minimal dependence. We illustrate an isomorphism between packet switch schedulers and Clos networks to develop such schedulers.(cont.) Next, we evaluate the amount of resource speedup necessary for single stage switches to support multicast rates. This speedup limits the scalability of a single stage multicast switch a great deal. We present an in depth study of multistage switches and propose a number of architectures, along with associated routing and scheduling algorithms. We illustrate how the presence of multiple paths between input output pairs can be exploited to improve the performance of a switch and simplify the scheduling algorithms. Some of our architectures are capable of providing multicast rate guarantees without a need for a resource speedup. We extend our results on switch schedulers and use them for providing service guarantees over optical wavelength switches. We will take the limitations of the optical crossconnects and unavailability of optical memory technology into account, and modify the procedure we developed for electronic switches to make them suitable for various optical wavelength switches. These results will provide understanding of when to move optical switching closer to the end users for an efficient utilization of resources in networks with both optical and electronic technologies.by Can Emre Koksal.Ph.D