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From the Publisher: The indispensable guide to wireless communications—now fully revised and updated! Wireless Communications: Principles and Practice, Second Edition is the definitive modern text for wireless communications technology and system design. Building on his classic first edition, Theodore S. Rappaport covers the fundamental issues impacting all wireless networks and reviews virtually every important new wireless standard and technological development, offering especially comprehensive coverage of the 3G systems and wireless local area networks (WLANs) that will transform communications in the coming years. Rappaport illustrates each key concept with practical examples, thoroughly explained and solved step by step. Coverage includes: An overview of key wireless technologies: voice, data, cordless, paging, fixed and mobile broadband wireless systems, and beyond Wireless system design fundamentals: channel assignment, handoffs, trunking efficiency, interference, frequency reuse, capacity planning, large-scale fading, and more Path loss, small-scale fading, multipath, reflection, diffraction, scattering, shadowing, spatial-temporal channel modeling, and microcell/indoor propagation Modulation, equalization, diversity, channel coding, and speech coding New wireless LAN technologies: IEEE 802.11a/b, HIPERLAN, BRAN, and other alternatives New 3G air interface standards, including W-CDMA, cdma2000, GPRS, UMTS, and EDGE Bluetooth wearable computers, fixed wireless and Local Multipoint Distribution Service (LMDS), and other advanced technologies Updated glossary of abbreviations and acronyms, and a thorolist of references Dozens of new examples and end-of-chapter problems Whether you're a communications/network professional, manager, researcher, or student, Wireless Communications: Principles and Practice, Second Edition gives you an in-depth understanding of the state of the art in wireless technology—today's and tomorrow's.

Frequencies from 100 GHz to 3 THz are promising bands for the next generation of wireless communication systems because of the wide swaths of unused and unexplored spectrum. These frequencies also offer the potential for revolutionary applications that will be made possible by new thinking, and advances in devices, circuits, software, signal processing, and systems. This paper describes many of the technical challenges and opportunities for wireless communication and sensing applications above 100 GHz, and presents a number of promising discoveries, novel approaches, and recent results that will aid in the development and implementation of the sixth generation (6G) of wireless networks, and beyond. This paper shows recent regulatory and standard body rulings that are anticipating wireless products and services above 100 GHz and illustrates the viability of wireless cognition, hyper-accurate position location, sensing, and imaging. This paper also presents approaches and results that show how long distance mobile communications will be supported to above 800 GHz since the antenna gains are able to overcome air-induced attenuation, and present methods that reduce the computational complexity and simplify the signal processing used in adaptive antenna arrays, by exploiting the Special Theory of Relativity to create a cone of silence in over-sampled antenna arrays that improve performance for digital phased array antennas. Also, new results that give insights into power efficient beam steering algorithms, and new propagation and partition loss models above 100 GHz are given, and promising imaging, array processing, and position location results are presented. The implementation of spatial consistency at THz frequencies, an important component of channel modeling that considers minute changes and correlations over space, is also discussed. This paper offers the first in-depth look at the vast applications of THz wireless products and applications and provides approaches for how to reduce power and increase performance across several problem domains, giving early evidence that THz techniques are compelling and available for future wireless communications.

When computer networks link people as well as machines, they become social networks. Such computer-supported social networks (CSSNs) are becoming important bases of virtual communities, computer-supported cooperative work, and telework. Computer-mediated communication such as electronic mail and computerized conferencing is usually text-based and asynchronous. It has limited social presence, and on-line communications are often more uninhibited, creative, and blunt than in-person communication. Nevertheless, CSSNs sustain strong, intermediate, and weak ties that provide information and social support in both specialized and broadly based relationships. CSSNs foster virtual communities that are usually partial and narrowly focused, although some do become encompassing and broadly based. CSSNs accomplish a wide variety of cooperative work, connecting workers within and between organizations who are often physically dispersed. CSSNs also link teleworkers from their homes or remote work centers to main organizational offices. Although many relationships function off-line as well as on-line, CSSNs have developed their own norms and structures. The nature of the medium both constrains and facilitates social control. CSSNs have strong societal implications, fostering situations that combine global connectivity, the fragmentation of solidarities, the de-emphasis of local organizations (in the neighborhood and workplace), and the increased importance of home bases.

As the standardization of 5G solidifies, researchers are speculating what 6G will be. The integration of sensing functionality is emerging as a key feature of the 6G Radio Access Network (RAN), allowing for the exploitation of dense cell infrastructures to construct a perceptive network. In this IEEE Journal on Selected Areas in Communications (JSAC) Special Issue overview, we provide a comprehensive review on the background, range of key applications and state-of-the-art approaches of Integrated Sensing and Communications (ISAC). We commence by discussing the interplay between sensing and communications (S&C) from a historical point of view, and then consider the multiple facets of ISAC and the resulting performance gains. By introducing both ongoing and potential use cases, we shed light on the industrial progress and standardization activities related to ISAC. We analyze a number of performance tradeoffs between S&C, spanning from information theoretical limits to physical layer performance tradeoffs, and the cross-layer design tradeoffs. Next, we discuss the signal processing aspects of ISAC, namely ISAC waveform design and receive signal processing. As a step further, we provide our vision on the deeper integration between S&C within the framework of perceptive networks, where the two functionalities are expected to mutually assist each other, i.e., via communication-assisted sensing and sensing-assisted communications. Finally, we identify the potential integration of ISAC with other emerging communication technologies, and their positive impacts on the future of wireless networks.

(Most chapters contain a Summary.) Preface xiii. SECTION II. INTRODUCTION. 1. Atoms, Bits, and Networks. Introduction. Common Network Technologies. Networking Concepts and Techniques. Engineering Computer Networks. In Closing. 2. The Telephone Network: Concepts, History, and Challenges. Concepts. End-Systems. Transmission. Switching. Signaling. Cellular Communications. Historical Sketch. Challenges. Summary. 3. The Internet: Concepts, History, and Challenges. Concepts. Basic Internet Technology. Addressing. Routing. Endpoint Control. History. Challenges. Summary. 4. Atm Networks: Concepts, History, and Challenges. Virtual Circuits. Fixed-Size Packets. Small Packet Size. Statistical Multiplexing. Integrated Service. History. Challenges. Summary. SECTION II. TOOLS AND TECHNIQUES. 5. Protocol Layering. Protocols and Protocol Layering. Importance of Layering. Problems With Layering. Iso-Osi Reference Model. The Seven Layers. Summary. 6. System Design. Introduction. Resource Constraints and Their Metrics. Common Design Techniques. Performance Analysis and Tuning. Summary. 7. Multiple Access. Introduction. Choices and Constraints. Base Technologies. Centralized Access Schemes. Distributed Schemes. Summary. 8. Switching. Introduction. Circuit Switching. Packet Switching. Switch Fabrics. Buffering. Multicasting. Summary. 9. Scheduling. Introduction. Requirements. Fundamental Choices. Scheduling Best-Effort Connections. Scheduling Guaranteed-Service Connections. Comparison. Packet Dropping. Summary. 10. Naming and Addressing. Introduction. Naming and Addressing. Hierarchical Naming. Addressing. Addressing in the Telephone Network. Addressing in the Internet. Nsaps: Addressing in ATM Networks. Name Resolution. Datalink Layer Addressing. Finding Datalink Layer Addresses. Summary. 11. Routing. Introduction. Routing Protocol Requirements. Choices. Routing in the Telephone Network. Distance-Vector Routing. Link-State Routing. Choosing Link Costs. Hierarchical Routing. Internet Routing Protocols. Routing Within a Broadcast Lan. Multicast Routing. Routing With Policy Constraints. Routing for Mobile Hosts. Summary. 12. Error Control. Causes of Bit Errors. Bit-Error Detection and Correction. Causes of Packet Errors. Packet-Error Detection and Correction. Summary. 13. Flow Control. Model. Classification. Open-Loop Flow Control. Closed-Loop Flow Control. Hybrid Flow Control. Summary. 14. Traffic Management. Introduction. An Economic Framework for Traffic Management. Traffic Models. Traffic Classes. Time Scales of Traffic Management. Scheduling. Renegotiation. Signaling. Admission Control. Peak-Load Pricing. Capacity Planning. Summary. SECTION III. PRACTICE. 15. Common Protocols. Introduction. Telephone Network Protocols. Internet Protocols. Atm Network Protocols. Ip Over Atm. Summary. 16. Protocol Implementation. Introduction. Factors Affecting Protocol Stack Performance. Common Protocol Stack Procedures. Partitioning Strategies. Interface Among Protocol Layers. Protocol Implementation. Some Rules of Thumb. Summary. References. Glossary. Answers to Review Questions and Selected Exercises. Index. 0201634422T04062001

Two-time winner of the best Computer Science and Engineering textbook of the year award from the Textbook and Academic Authors AssociationFor a one/two-semester courses in Computer Networks, Data Communications, and Communications Networks in CS, CIS, and Electrical Engineering departments. With a focus on the most current technology and a convenient modular format, this best-selling text offers a clear and comprehensive survey of the entire data and computer communications field. Emphasizing both the fundamental principles as well as the critical role of performance in driving protocol and network design, it explores in detail all the critical technical areas in data communications, wide-area networking, local area networking, and protocol design

The International Journal of Computer Networks & Communications (IJCNC) is a top reputed, Scopus indexed, UGC approved Journal, also Listed in ERA that publishes research articles which contribute new results in all areas of Computer Networks & Communications. The journal focuses on all technical and practical aspects of Computer Networks & Data Communications

The development of resource-sharing networks can facilitate the provision of a wide range of economic and reliable computer services. Computer-communication networks allow the sharing of specialized computer resources such as data bases, programs, and hardware. Such a network consists of both the computer resources and a communications system interconnecting them and allowing their full utilization to be achieved. In addition, a resource-sharing network provides the means whereby increased cooperation and interaction can be achieved between individuals. An introduction to computer-to-computer networks and resource sharing is provided and some aspects of distributed computation are discussed.

STARNET is a broadband backbone optical wavelength-division multiplexing (WDM) local area network (LAN). Based on a physical passive star topology, STARNET offers all users two logical subnetworks: a high-speed reconfigurable packet-switched data subnetwork and a moderate-speed fix-tuned packet-switched control subnetwork. Thus, STARNET supports traffic with a wide range of speed and continuity characteristics. We report the analysis and implementation of an entire STARNET two-node network, from the optical to the computer layer, at the Optical Communications Research Laboratory (OCRL) of Stanford University. To implement the two logical subnetworks, we designed and implemented two different techniques: combined modulation and multichannel subcarrier multiplexing (MSCM). OCRL has already demonstrated several combined modulation techniques such as phase shift-keyed and amplitude shift-keyed (PSK/ASK), and differential phase shift-keyed and amplitude shift-keyed (DPSK/ASK), yielding combined ASK/DPSK modulation receiver sensitivities better than -32 dBm. OCRL has designed and implemented a high-speed high-performance packet-switched STARNET computer interface which enables high-throughput transfer to/from host computer, low latency switching, traffic prioritization, and capability of multicasting and broadcasting. With this interface board, OCRL has achieved average transmit and receive throughputs of 685 Mb/s and 571 Mb/s, respectively, out of the 800 Mb/s theoretical maximum of the host computer bus. The incurred packet latency due to the interface for a specified multihop network configuration has been simulated to be 24 /spl mu/s. Using simulation and experimental results, it is shown that STARNET is highly suitable for high-speed multimedia network applications.

This text is intended as a comprehensive guide to the design and analysis of computer communications protocols. It introduces a sound discipline for the design of complete and consistent protocol systems, independent of where they are used. This volume discusses the fundamental problems of designing logically consistent methods of communication between multiple computer processes. Standard protocol design problems, such as error control and flow control, are covered in detail, but also structured design methods and the construction of formal validation models. The book contains complete listings and explanations of new protocol validation and design tool called SPIN. Author is in charge of protocol design at Bell Labs. Professionals who bought Tanenbaum's COMPUTER NETWORKS, 2/E and Comer's TCP/IP will buy this. This is the first book to cover automated protocol design and validation tools extensively.

The future of mobile communications looks exciting with the potential new use cases and challenging requirements of future 6th generation (6G) and beyond wireless networks. Since the beginning of the modern era of wireless communications, the propagation medium has been perceived as a randomly behaving entity between the transmitter and the receiver, which degrades the quality of the received signal due to the uncontrollable interactions of the transmitted radio waves with the surrounding objects. The recent advent of reconfigurable intelligent surfaces in wireless communications enables, on the other hand, network operators to control the scattering, reflection, and refraction characteristics of the radio waves, by overcoming the negative effects of natural wireless propagation. Recent results have revealed that reconfigurable intelligent surfaces can effectively control the wavefront, e.g., the phase, amplitude, frequency, and even polarization, of the impinging signals without the need of complex decoding, encoding, and radio frequency processing operations. Motivated by the potential of this emerging technology, the present article is aimed to provide the readers with a detailed overview and historical perspective on state-of-the-art solutions, and to elaborate on the fundamental differences with other technologies, the most important open research issues to tackle, and the reasons why the use of reconfigurable intelligent surfaces necessitates to rethink the communication-theoretic models currently employed in wireless networks. This article also explores theoretical performance limits of reconfigurable intelligent surface-assisted communication systems using mathematical techniques and elaborates on the potential use cases of intelligent surfaces in 6G and beyond wireless networks.

The statistical nature of Monte Carlo techniques presents significant computational problems in the simulation of computer communications networks. A variety of techniques has been developed over the years to improve the computational efficiency of simulation models of general queuing networks, some of which have been applied to communication networks. The authors review the status of efficiency-enhancing techniques as they relate to the simulation of computer communications networks, present some novel approaches, and suggest promising areas for future research.>

BACKGROUND: Recent technological advances in integrated circuits, wireless communications, and physiological sensing allow miniature, lightweight, ultra-low power, intelligent monitoring devices. A number of these devices can be integrated into a Wireless Body Area Network (WBAN), a new enabling technology for health monitoring. METHODS: Using off-the-shelf wireless sensors we designed a prototype WBAN which features a standard ZigBee compliant radio and a common set of physiological, kinetic, and environmental sensors. RESULTS: We introduce a multi-tier telemedicine system and describe how we optimized our prototype WBAN implementation for computer-assisted physical rehabilitation applications and ambulatory monitoring. The system performs real-time analysis of sensors' data, provides guidance and feedback to the user, and can generate warnings based on the user's state, level of activity, and environmental conditions. In addition, all recorded information can be transferred to medical servers via the Internet and seamlessly integrated into the user's electronic medical record and research databases. CONCLUSION: WBANs promise inexpensive, unobtrusive, and unsupervised ambulatory monitoring during normal daily activities for prolonged periods of time. To make this technology ubiquitous and affordable, a number of challenging issues should be resolved, such as system design, configuration and customization, seamless integration, standardization, further utilization of common off-the-shelf components, security and privacy, and social issues.

Starting with the historical evolution of computer and communications networks and their security, the book then arrives at the main definitions of cryptography and network security. Next, the basics of information theory, how to measure information, the information associated with a certain source are also discussed. Source codes are presented, along with the concepts of information transmission, joint information, conditional entropy, mutual information and channel capacity. Computer networks are discussed, including the main protocols and network architectures, and the important TCP/IP protocol. Network security, a topic intrinsically connected to computer networks and the Internet, is presented, along with information about basic hacker attacks, alternatives to prevent attacks, data protection and secure protocols. The information theoretical aspects of cryptography are described including the hash function. An appendix includes a review of probability theory. Illustrations and graphics will help the reader understand the theory.

This paper introduces AntNet, a novel approach to the adaptive learning of routing tables in communications networks. AntNet is a distributed, mobile agents based Monte Carlo system that was inspired by recent work on the ant colony metaphor for solving optimization problems. AntNet's agents concurrently explore the network and exchange collected information. The communication among the agents is indirect and asynchronous, mediated by the network itself. This form of communication is typical of social insects and is called stigmergy. We compare our algorithm with six state-of-the-art routing algorithms coming from the telecommunications and machine learning fields. The algorithms' performance is evaluated over a set of realistic testbeds. We run many experiments over real and artificial IP datagram networks with increasing number of nodes and under several paradigmatic spatial and temporal traffic distributions. Results are very encouraging. AntNet showed superior performance under all the experimental conditions with respect to its competitors. We analyze the main characteristics of the algorithm and try to explain the reasons for its superiority.