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

We present the design, implementation, and evaluation of B4, a private WAN connecting Google's data centers across the planet. B4 has a number of unique characteristics: i) massive bandwidth requirements deployed to a modest number of sites, ii) elastic traffic demand that seeks to maximize average bandwidth, and iii) full control over the edge servers and network, which enables rate limiting and demand measurement at the edge.These characteristics led to a Software Defined Networking architecture using OpenFlow to control relatively simple switches built from merchant silicon. B4's centralized traffic engineering service drives links to near 100% utilization, while splitting application flows among multiple paths to balance capacity against application priority/demands. We describe experience with three years of B4 production deployment, lessons learned, and areas for future work.

/pdf/b4-experience-with-a-globally-deployed-software-defined-wan-2ejcv4i1og.pdf

B4: experience with a globally-deployed software defined wan

The Transmission Control Protocol.

We examine the cooling radiation from forming galaxies in hydrodynamic simulations of the LCDM model (cold dark matter with a cosmological constant), focusing on the Ly? line luminosities of high-redshift systems. Primordial composition gas condenses within dark matter potential wells, forming objects with masses and sizes comparable to the luminous regions of observed galaxies. As expected, the energy radiated in this process is comparable to the gravitational binding energy of the baryons, and the total cooling luminosity of the galaxy population peaks at z ? 2. However, in contrast to the classical picture of gas cooling from the ~106 K virial temperature of a typical dark matter halo, we find that most of the cooling radiation is emitted by gas with T < 20,000 K. As a consequence, roughly 50% of this cooling radiation emerges in the Ly? line. While a galaxy's cooling luminosity is usually smaller than the ionizing continuum luminosity of its young stars, the two are comparable in the most massive systems, and the cooling radiation is produced at larger radii, where the Ly? photons are less likely to be extinguished by dust. We suggest, in particular, that cooling radiation could explain the two large (~100 kpc), luminous (LLy? ~ 1044 ergs s-1) blobs of Ly? emission found in the narrowband survey of a z = 3 protocluster by Steidel and collaborators. Our simulations predict objects of the observed luminosity at about the right space density, and radiative transfer effects can account for the observed sizes and line widths. We discuss observable tests of this hypothesis for the nature of the Ly? blobs, and we present predictions for the contribution of cooling radiation to the Ly? luminosity function of galaxies as a function of redshift.

https://scholarworks.umass.edu/cgi/viewcontent.cgi?article=1347&context=astro_faculty_pubs

Cooling Radiation and the Lyα Luminosity of Forming Galaxies

Security has become the primary concern in many telecommunications industries today as risks can have high consequences. Especially, as the core and enable technologies will be associated with 5G network, the confidential information will move at all layers in future wireless systems. Several incidents revealed that the hazard encountered by an infected wireless network, not only affects the security and privacy concerns, but also impedes the complex dynamics of the communications ecosystem. Consequently, the complexity and strength of security attacks have increased in the recent past making the detection or prevention of sabotage a global challenge. From the security and privacy perspectives, this paper presents a comprehensive detail on the core and enabling technologies, which are used to build the 5G security model; network softwarization security, PHY (Physical) layer security and 5G privacy concerns, among others. Additionally, the paper includes discussion on security monitoring and management of 5G networks. This paper also evaluates the related security measures and standards of core 5G technologies by resorting to different standardization bodies and provide a brief overview of 5G standardization security forces. Furthermore, the key projects of international significance, in line with the security concerns of 5G and beyond are also presented. Finally, a future directions and open challenges section has included to encourage future research.

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A Survey on Security and Privacy of 5G Technologies: Potential Solutions, Recent Advancements, and Future Directions

Batch arrival queue with N -policy and single vacation

Disclosed is hop-count based content caching. The present invention implements hop-count based content cache placement strategies that efficiently decrease traffics of a network by the routing node's primarily judging whether to cache a content chunk by grasping an attribute of the received content chunk; the routing node's secondarily judging whether to cache the content chunk based on a caching probability of ‘1/hop count’; and storing the content chunk and the hop count information in the cache memory of the routing node when the content chunk is determined to cache the content chunk as a result of the secondary judgment.

Method for managing content caching based on hop count and network entity thereof

A traffic measurement system and a traffic analysis method are provided. The traffic measurement system includes a plurality of measurement devices that collect all of packets flowing through Internet links, extract traffic data required to analyze traffic from the collected packets, and process the extracted data into predetermined flow types, and an analysis server that identifies applications of traffic by analyzing the traffic data transferred from the plurality of measurement devices as a whole, classifies the identified applications into predetermined traffic types, and outputs the classification result. The traffic measurement system measures the traffics in the Internet network and processes the measured traffics to generate detailed traffic statistical data according to applications. In particular, the traffics are analyzed considering measurement data from various points, and the data for identifying the applications are extracted from headers of the applications included in payloads of IP packets in real time. Accordingly, detailed traffic analysis result is provided.

Traffic measurement system and traffic analysis method thereof

Cloud computing can bring many advantages for companies such as cost efficiency, reducing time to access to the market, ease to use, flexibility and adaptability to change to different condition, etc. However, the adoption rate in Vietnam is still in the beginning stage with not many adopters. As a result, this study focuses on the adoption of cloud computing among Vietnamese companies. Eight factors were identified as determinants of cloud computing adoption by combining the two widely applied IT theories i.e. Diffusion on Innovation and Technology-Organization-Environment framework. In the future with eight factors we will conduct survey, factor analysis and logistic regression to determine factors affecting cloud computing adoption.

Seung Hyun Yoon

Papers

Batch arrival queue with N -policy and single vacation

Method for managing content caching based on hop count and network entity thereof

Traffic measurement system and traffic analysis method thereof

The determinant of adoption in cloud computing in Vietnam

Queue length and waiting time analysis of a batch arrival queue with bilevel control