Praise for the Third Edition: "This is one of the best books available. Its excellent organizational structure allows quick reference to specific models and its clear presentation . . . solidifies the understanding of the concepts being presented."IIE Transactions on Operations EngineeringThoroughly revised and expanded to reflect the latest developments in the field, Fundamentals of Queueing Theory, Fourth Edition continues to present the basic statistical principles that are necessary to analyze the probabilistic nature of queues. Rather than presenting a narrow focus on the subject, this update illustrates the wide-reaching, fundamental concepts in queueing theory and its applications to diverse areas such as computer science, engineering, business, and operations research.This update takes a numerical approach to understanding and making probable estimations relating to queues, with a comprehensive outline of simple and more advanced queueing models. Newly featured topics of the Fourth Edition include:Retrial queuesApproximations for queueing networksNumerical inversion of transformsDetermining the appropriate number of servers to balance quality and cost of serviceEach chapter provides a self-contained presentation of key concepts and formulae, allowing readers to work with each section independently, while a summary table at the end of the book outlines the types of queues that have been discussed and their results. In addition, two new appendices have been added, discussing transforms and generating functions as well as the fundamentals of differential and difference equations. New examples are now included along with problems that incorporate QtsPlus software, which is freely available via the book's related Web site.With its accessible style and wealth of real-world examples, Fundamentals of Queueing Theory, Fourth Edition is an ideal book for courses on queueing theory at the upper-undergraduate and graduate levels. It is also a valuable resource for researchers and practitioners who analyze congestion in the fields of telecommunications, transportation, aviation, and management science.

Fundamentals of Queueing Theory

Optical wireless communication (OWC) refers to transmission in unguided propagation media through the use of optical carriers, i.e., visible, infrared (IR), and ultraviolet (UV) bands. In this survey, we focus on outdoor terrestrial OWC links which operate in near IR band. These are widely referred to as free space optical (FSO) communication in the literature. FSO systems are used for high rate communication between two fixed points over distances up to several kilometers. In comparison to radio-frequency (RF) counterparts, FSO links have a very high optical bandwidth available, allowing much higher data rates. They are appealing for a wide range of applications such as metropolitan area network (MAN) extension, local area network (LAN)-to-LAN connectivity, fiber back-up, backhaul for wireless cellular networks, disaster recovery, high definition TV and medical image/video transmission, wireless video surveillance/monitoring, and quantum key distribution among others. Despite the major advantages of FSO technology and variety of its application areas, its widespread use has been hampered by its rather disappointing link reliability particularly in long ranges due to atmospheric turbulence-induced fading and sensitivity to weather conditions. In the last five years or so, there has been a surge of interest in FSO research to address these major technical challenges. Several innovative physical layer concepts, originally introduced in the context of RF systems, such as multiple-input multiple-output communication, cooperative diversity, and adaptive transmission have been recently explored for the design of next generation FSO systems. In this paper, we present an up-to-date survey on FSO communication systems. The first part describes FSO channel models and transmitter/receiver structures. In the second part, we provide details on information theoretical limits of FSO channels and algorithmic-level system design research activities to approach these limits. Specific topics include advances in modulation, channel coding, spatial/cooperative diversity techniques, adaptive transmission, and hybrid RF/FSO systems.

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Survey on Free Space Optical Communication: A Communication Theory Perspective

Light-Emitting Diodes. (Monographs in Electrical and Electronic Engineering.) By A. A. Bergh and P. J. Dean. Pp. viii+591. (Clarendon: Oxford; Oxford University: London, 1976.) £22.

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Light-emitting diodes

Course Description This is an advanced course in which we explore the field of Statistical Optics. Topics covered include such subjects as the statistical properties of natural (thermal) and laser light, spatial and temporal coherence, effects of partial coherence on optical imaging instruments, effects on imaging due to randomly inhomogeneous media, and a statistical treatment of the detection of light. Development of this more comprehensive model of the behavior of light draws upon the use of tools traditionally available to the electrical engineer, such as linear system theory and the theory of stochastic processes.

http://ieeexplore.ieee.org/iel5/3/23094/01073023.pdf

Statistical optics

The solid-state lighting is revolutionizing the indoor illumination. Current incandescent and fluorescent lamps are being replaced by the LEDs at a rapid pace. Apart from extremely high energy efficiency, the LEDs have other advantages such as longer lifespan, lower heat generation, and improved color rendering without using harmful chemicals. One additional benefit of LEDs is that they are capable of switching to different light intensity at a very fast rate. This functionality has given rise to a novel communication technology (known as visible light communication—VLC) where LED luminaires can be used for high speed data transfer. This survey provides a technology overview and review of existing literature of visible light communication and sensing. This paper provides a detailed survey of 1) visible light communication system and characteristics of its various components such as transmitter and receiver; 2) physical layer properties of visible light communication channel, modulation methods, and MIMO techniques; 3) medium access techniques; 4) system design and programmable platforms; and 5) visible light sensing and application such as indoor localization, gesture recognition, screen-camera communication, and vehicular networking. We also outline important challenges that need to be addressed in order to design high-speed mobile networks using visible light communication.

Visible Light Communication, Networking, and Sensing: A Survey, Potential and Challenges

We report a visible-light wireless point-to-point communication link operating at 513 Mbit/s gross transmission rate (net Mbit/s). The bit-error ratio of the uncoded data was smaller than for an illumination level of lx. The link was based on a commercial thin-film high-power phosphorescent white LED, an avalanche photo diode, and off-line signal processing of discrete multitone signals. Quadrature-amplitude modulation, bit- and power-loading, as well as symmetrical clipping were successfully employed in pushing the gross transmission rate beyond 500 Mbit/s. Adaptation of the clipping level increased the data rate only by 2%, while simulations predicted an enhancement of 20%. Obstacles towards higher data rates as well as potential remedies are discussed. We predicted that data rates of over 1 Gbit/s can be achieved with the same setup and under the same experimental conditions if these obstacles are overcome.

513 Mbit/s Visible Light Communications Link Based on DMT-Modulation of a White LED

Emergence of white-light LEDs allows the combination of lighting and information broadcast functionality in one optical source. We investigate analytically and by Monte Carlo simulations feasible data transmission rates in a moderate-size office room, where we assume illumination conforming to standards and the use of commercially available LEDs and photodiodes. The performances of systems relying on baseband [i.e., pulse-amplitude modulation (PAM)] and discrete multitone (DMT) transmission show that data rates of more than 100 Mbit/s can be expected despite the rather low bandwidth of the system.

/pdf/broadband-information-broadcasting-using-led-based-interior-1rk2uzlykq.pdf

Broadband Information Broadcasting Using LED-Based Interior Lighting

This article presents recent achievements and trends in high-speed indoor visible light communication (VLC) research. We address potential applications and future visions for the VLC technology, where transport of information is “piggybacked” on the original lighting function of LED-based lamps. To mature this technology and transfer it into practice, our recent research is focused on real-time implementation and trials. For the first time, a bidirectional real-time VLC prototype achieving data rates of up to 500 Mb/s is presented. This system paves the way for future real world applications. Finally, we discuss the remaining technical challenges as well as the research outlook in the field of high-speed VLC systems.

High-speed visible light communication systems

We report the first visible light link based on WDM and DMT modulation of a single RGB-type white LED, operating at an aggregate rate of 803 Mbit/s within the FEC 2·10−3 limit.

803 Mbit/s visible light WDM link based on DMT modulation of a single RGB LED luminary

Zusammenfassung: Durch doppelte Nutzung ermöglichen Weißlicht-LEDs Synergie von Raumbeleuchtung und drahtloser optischer Kommunikation/ Nachrichtenverteilung. Für einen mit LEDs gut ausgeleuchteten mittelgroßen Büroraum wird die erreichbare Datenrate bei Basisbandund DMT-Übertragung ermittelt, wobei der Einsatz handelsüblicher LEDs und Photodioden angenommen wird. Die Resultate zeigen, dass trotz relativ geringer Systembandbreite Bitraten von mehr als 100 Mbit/s zu erwarten sind. Summary: Emergence of white-light LEDs allows synergy of lighting and broadcast/communication function in one optical source. We investigate possible data transmission rates in a moderate-size office room where we assume illumination conforming to standards and the use of commercially available LEDs and photodiodes. The performances of systems relying on base-band and DMT transmission show that data rates of more than 100 Mbit/s can be expected despite the rather low bandwidth of the system.

Klaus-Dieter Langer

Papers

513 Mbit/s Visible Light Communications Link Based on DMT-Modulation of a White LED

Broadband Information Broadcasting Using LED-Based Interior Lighting

High-speed visible light communication systems

803 Mbit/s visible light WDM link based on DMT modulation of a single RGB LED luminary

High-Speed Wireless Indoor Communication via Visible Light