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

A unified messaging system that provides a multimedia mailbox. The system allows a subscriber to access stored multimedia messages, such as voicemail messages, facsimile messages, combined voice and facsimile messages and video messages, not only through a public switched telephone network using a telephone but also over a data network, such as the Internet or an intranet, using a personal computer. The system provides voicemail access over the telephone network, indicating message number, etc. with the ability to play messages to the telephone user as desired. For text type messages, such as facsimile and e-mail, the system converts the text into speech and plays the speech to the telephone user. The system allows a personal computer user to obtain the data network access using an Internet browser. The browser is used to access a home page of the system and get information about the messages stored, and is used to download (get) and play the messages at the personal computer via data streaming in the case of a voice or video messages or view the messages in the case of text type messages, such as facsimile and e-mail. The user can also perform the other typical messaging functions over the data network connection that are provided for telephone access, such as viewing a message list, saving and deleting messages, group list administration and other administration tasks.

A system for accessing multimedia mailboxes and messages over the internet and via telephone

As wireless video is the fastest growing form of data traffic, methods for spectrally efficient on-demand wireless video streaming are essential to both service providers and users. A key property of video on-demand is the asynchronous content reuse , such that a few popular files account for a large part of the traffic but are viewed by users at different times. Caching of content on wireless devices in conjunction with device-to-device (D2D) communications allows to exploit this property, and provide a network throughput that is significantly in excess of both the conventional approach of unicasting from cellular base stations and the traditional D2D networks for “regular” data traffic. This paper presents in a tutorial and concise form some recent results on the throughput scaling laws of wireless networks with caching and asynchronous content reuse, contrasting the D2D approach with other alternative approaches such as conventional unicasting, harmonic broadcasting , and a novel coded multicasting approach based on caching in the user devices and network-coded transmission from the cellular base station only. Somehow surprisingly, the D2D scheme with spatial reuse and simple decentralized random caching achieves the same near-optimal throughput scaling law as coded multicasting. Both schemes achieve an unbounded throughput gain (in terms of scaling law) with respect to conventional unicasting and harmonic broadcasting, in the relevant regime where the number of video files in the library is smaller than the total size of the distributed cache capacity in the network. To better understand the relative merits of these competing approaches, we consider a holistic D2D system design incorporating traditional microwave (2 GHz) and millimeter-wave (mm-wave) D2D links; the direct connections to the base station can be used to provide those rare video requests that cannot be found in local caches. We provide extensive simulation results under a variety of system settings and compare our scheme with the systems that exploit transmission from the base station only. We show that, also in realistic conditions and nonasymptotic regimes, the proposed D2D approach offers very significant throughput gains.

Wireless Device-to-Device Caching Networks: Basic Principles and System Performance

A Message Storage and Deliver System (MSDS) is connected to the public switched telephone network (PSTN) and receives incoming calls with these calls being facsimile, voice, or data transmissions. The MSDS detects the type of call and stores the message signal in a database. The MSDS is also connected to the Internet and has a hyper-text transfer protocol deamon (HTTPD) for receiving requests from users. The HTTPD forwards requests for certain files or messages to a network server which transmits at least part of the message to the HTTPD and then to the user. In addition to requests for certain documents, the HTTPD may also receive a request in the form of a search query. The search query is forwarded from the HTTPD to an application program for conducting the search of the database. The results of the search are forwarded through the HTTPD to the user. The user may then select one or more files or messages from the search results and may save the search for later reference.

Systems and methods for storing, delivering, and managing messages

Network Simulator NS2

Using conventional broadcasting, if we want to support a 120-minute popular movie every 10 minutes, we need 12 video channels. Assuming the set-top box at the client end can buffer portions of the playing video on a disk, pyramid broadcasting schemes can reduce the bandwidth requirements to 5.7 channels. We present a new scheme which only needs 3.2 channels. For a movie with length D minutes, if we want to reduce the viewer waiting time to D/N minutes, we only need to allocate H(N) video channels to broadcast the movie periodically, where H(N) is the harmonic number of N, H(N)=1+1/2+...+1/N. In order to support video-on-demand service for a popular movie, the new scheme greatly reduces the bandwidth requirements.

Harmonic broadcasting for video-on-demand service

Using multiple channels to broadcast a popular video can reduce the viewer's waiting time to approach video-on-demand service. For a given bandwidth allocation, pyramid broadcasting schemes can provide users with shorter waiting time as compared with conventional broadcasting schemes. However, for a 120-minute movie, the waiting time is only reduced to 20 minutes as we allocate 4 video channels for the movie. The harmonic broadcasting scheme can reduce the waiting time to 4 minutes but it can not support the live telecast. This paper presents a new broadcasting scheme, which can support live videos and reduce the waiting time to 8 minutes for the above case. With the same waiting requirement for a hot video, the new scheme can greatly reduce the bandwidth requirements and provide heterogeneous users' services.

Fast data broadcasting and receiving scheme for popular video service

For a 120-minute popular movie, with 4 video channels, current digital video broadcasting systems can support the movie every 30 minutes. Suppose the set-top box at client end can buffer portions of the playing video on disk. Pyramid broadcasting schemes can support the movie every 19 minutes. We present a new data broadcasting and receiving scheme, which can service the movie every 8 minutes. For a given bandwidth allocation, the new scheme greatly reduces the viewer waiting time. The disk space and transfer rate requirements of the set-top box are also reduced to be feasible.

Staircase data broadcasting and receiving scheme for hot video service

For a popular movie, in order to minimize the service delay with a given bandwidth, currently the harmonic broadcasting scheme can provide users with the shortest waiting time to approach near video-on-demand service. This paper presents an enhanced scheme, which can improve the bandwidth utilization and reduce further the viewers' waiting time.

Enhanced harmonic data broadcasting and receiving scheme for popular video service

In order to approach a video-on-demand (VOD) service, we can allocate more bandwidth to broadcast a popular video more frequently to reduce viewers' waiting time. Using a broadcasting scheme to support a popular video periodically, in order to guarantee a given waiting time, the harmonic broadcasting scheme needs the least bandwidth in the existing schemes. In this paper, we show that using any broadcasting scheme, the minimum bandwidth requirement for the same waiting time is the same as the harmonic broadcasting scheme. Therefore, for a popular video, in order to approach a near VOD service, the harmonic broadcasting scheme is an optimal broadcasting scheme that needs the least bandwidth for a given viewers' waiting time.

Li-Ming Tseng

Papers

Harmonic broadcasting for video-on-demand service

Fast data broadcasting and receiving scheme for popular video service

Staircase data broadcasting and receiving scheme for hot video service

Enhanced harmonic data broadcasting and receiving scheme for popular video service

On optimal broadcasting scheme for popular video service