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Chapter 18 surveys routing algorithms in communication networks, where nodes are aware of the geographic position of themselves and their neighboring nodes. Guaranteed delivery is a salient property of the algorithms, assuming destination location is accurate, all nodes have the same transmission radius, and there are no obstacles. [ABSTRACT FROM PUBLISHER]

Mao Zedong once said 'All genuine knowledge originates in direct experience'. Appendix B describes the experiences gained through a range of development projects, all concerned with the design, development, demonstration and maintenance of real broadband signalling systems. The authors of this appendix have participated in the development of a variety of systems offering broadband capabilities, all of which support some form of broadband signalling between the service user and service provider. The process of designing and building such systems can provide invaluable insights into issues such as development methods, signalling performance, programming interface definitions, etc., none of which are apparent from purely paper-based studies or through the standards specification process. [ABSTRACT FROM PUBLISHER]

The article presents information on wireless communications. The field of mobile wireless communications is currently one of the fastest growing segments of the telecommunications industry. Wireless devices have nowadays found extensive use and have become an indispensable tool on the everyday life of many people. both the professionally and personally. To gain insight into the momentum of the growth of the wireless industry, it is sufficient to state the tremendous growth in the number of worldwide subscribers of wireless systems. This figure has risen from only one mobile subscriber per 100 inhabitants worldwide in 1990 to 26 subscribers per 100 inhabitants in 1999 and the growth continues. This increasing number of subscribers is obviously reflected in monetary terms as well.

Discusses wireless data networks. Concept of internetworking; Functions of the Open System Interconnection (OSI) reference model; Purposes of each layers of the OSI model.

Focuses on the history of wireless technologies. Concept of the operational wireless telegraph apparatus developed by Guglielmo Marconi; Timeline on the evolution of wireless technologies; Functions of packet radio.

The article presents information about the packet transmission in a Code Division Multiple Access (CDMA) radio network. The author starts with dual-class traffic and then extends the analysis to multimedia systems. These two classes are characterized by a set of parameters. The Class 2 mobiles must be capable of variable rate transmission, dependent on available residual capacity and the base station capable of the corresponding reception. The information transmission rate to be used by the Class 2 users will be decided by the base station, using information about the population distribution in the system, and in the constrained transmit power case, knowledge of the received power ratio parameter. In practice, the user-population distribution may be a slowly changing variable. This would imply that Class 2 information rate changes do not have to be effected too often.

The article focuses on adaptive communications and the book layout. To justify the content of the book and to make suggestions on how the book should be studied, a generic block diagram of a digital communication system has been shown. The standard building blocks, information source, source encoder, encryptor, channel encoder and data modulator are used to produce a narrowband signal, for example, binary phase shift keying, quaternary phase shift keying or M-ary quadrature amplitude modulation MQAM carrying information content. The spreading of the signal spectra is obtained by real or complex multiplication of the narrowband signal by a code.

The article presents a throughput delay performance of a centralized unslotted Direct Sequence/Code Division Multiple Access (DS/CDMA) packet radio network (PRN) using bit rate adaptive location aware channel load sensing protocol (CLSP). The reverse link of a single-cell unslotted DS/CDMA PRN with infinite population and circle cell coverage centered to a hub station. Users communicate via the hub using different codes for packet transmissions with the same quality of service requirements. The radio packets considered herein are of medium access control layer.

Any continuous-time analogue signal can be converted into a digital signal by making discrete both the time and the amplitude axes. The process of making the amplitude axis discrete is called quantization. It consists of dividing the amplitude axis in contiguous intervals and in associating to all the amplitudes within any interval a single amplitude value chosen among them. A regenerator receives the incoming pulse stream and transmits a new regenerated pulse stream that replicates the original sequence as closely as possible. To regenerate the signal, timing information must be known so that the regenerated pulse stream can be transmitted with the proper intervals between the pulses.

The SDH technique poses peculiar timing issues that deserve a closer look. Historically, the timing aspects of telecommunications networks have often been reduced to a set of pragmatic parameters and limits to verify, while their underlying rationale has not been normally considered part of the education of telecommunications engineers. Moreover, new timing issues have been raised by SDH, which implies new phenomena generating jitter and wander. In spite of the numerous advantages offered by SDH compared to PDH, SDH made the issue of controlling the jitter and wander of the transported tributaries more delicate than in traditional PDH networks.

Network synchronization is a comprehensive expression that addresses in a wide sense any distribution of time and frequency over a network of clocks. This article deals with both the above aspects. First, network synchronization is introduced from a historical point of view, pointing out how network synchronization issues evolved with telephone networks. The tactics of point-to-point timing transfer is addressed in particular, describing how it can be achieved on PDH and SDH links and the relevant architectures. Network synchronization, at first an unknown issue as not relevant to network operation and performance, has played a role of increasing importance in telecommunications throughout this evolution process, especially since transmission and switching turned digital.

This article presents the introductory matter for the journal "Synchronization of Digital Telecommunications Networks." It provides a table of the contents, preface, acknowledgements, abbreviations and index of topics. Network synchronization has gained increasing importance in telecommunications throughout the last 30 years, especially since transmission and switching turned digital. Infact, the quality of most services offered by network operators to their customers is affected by network synchronization performance.

Investigates the performance gains achieved using adaptive antenna arrays at the base stations in a cellular network. Details on how adaptive antenna array modeled for employment in a network level simulator; Reviews of some of the different models available for simulating multipath environments; Presentation of the metric used for characterizing the performance of mobile cellular network without adaptive antenna arrays.

Discusses the application of Code Division Multiple Access (CDMA) third-generation mobile systems in communication services. Description on the utilization of CDMA in wireless communication systems; Development of the system for multiple access environment; Fundamentals for the frequency-domain spreading of the spectrum transmission.

Chapter 13 focuses on the transport layer in micro-cell and macro-cell wireless networks. The task in the transport layer is to organize the speed of transmission, acknowledgement and possible retransmission of every packet of a data transfer. It deals primarily with network congestion and reduced bandwidth problems. [ABSTRACT FROM PUBLISHER]

Chapter 2 reviews existing solutions to the location management problem. Mobile phone users move among base stations but do not always register with the current base station, to avoid communication overhead and excessive battery consumption. There exists a trade-off between the frequency of location update by the mobile phone user and the delay in locating a user when a phone call is made. [ABSTRACT FROM PUBLISHER]

Chapter 12 considers the design of digital audio broadcasting systems, which transmit whole ensembles consisting of multiple radio programs on a single channel. The task is to arrange services into a collection of ensembles for each request area, and to assign channels to the resulting ensembles. [ABSTRACT FROM PUBLISHER]

The article presents preliminary information on the January 2002 issue of the journal "GSM and UMTS: The Creation of Global Mobile Communication."

Chapter 12 covers the development of channels in new transmission media, such as satellites and fiber optics, as well as improvements to hard wire connections made possible because circuit designers have produced the hardware at the right time and at the right cost. The growing traffic of "conversations" between machines of various descriptions has accelerated the trend towards "digitization" of signals in the telephone network. The design of circuits capable of accepting data corrupted by noise, restoring and retransmitting them is discussed. [ABSTRACT FROM PUBLISHER]

Chapter 6 models computer networks by a graph and the two-terminal and all-terminal reliability (availability) are developed in terms of event spaces and cut- and tie-sets. More advanced graph transformations are introduced. Exact and approximate solutions are discussed. Design of backbone networks using minimum cost and maximum reliability spanning trees and enhancement methods are developed. [ABSTRACT FROM PUBLISHER]

The article focuses on the issues associated with the design of radio frequency (RF) hardware for a wideband software defined radio (SDR) capable of accommodating European mobile standards over the 1-5 GHz range, as a tool to illustrate the key design issues. SDR RF hardware design has two significant differences compared to traditional, single mode, requirements: first, no predetermined operating frequency; secondly, its channel bandwidth is also not predetermined. These two factors give rise to major design challenges with transceiver filtering and linearity.

This chapter focuses on communications subsystem performance enhancements potentially attainable via use of vibrating micromechanical resonator circuits in MEMS-based transceiver architectures. Section 12.2 begins by reviewing the issues involved with transceiver miniaturization, specifically focusing on the need for high Q. Section 12.3 follows with an overview of various micromechanical signal processing circuits, describing micromechanical tanks, filters, mixer-filters, and switches and providing sufficient detail to facilitate the incorporation of such circuits into communications subsystems. Specific transceiver architectures using such devices are then presented in Sections 12.4 and 12.5, with a focus on the specific performance enhancements afforded by each approach. Section 12.6 then serves as a reminder that this is still a fledgling technology, emphasizing the present limitations of this technology and giving a sprinkling of the specific research problems that must be solved before the architectures of Sections 12.4 and 12.5 can become a reality. Sections 12.7 and 12.7.4.1 finally close the chapter with details on techniques for combining mechanical and transistor circuits onto single chips. [ABSTRACT FROM PUBLISHER]

Can a silicon-based technology like Si/SiGe HBT exhibit performance compatible with the demands of the low-power wireless communications marketplace, and does it retain the low cost and manufacturability of its silicon pedigree? This chapter will attempt to answer that question by summarizing the progress and prospects for this technology in the area of low-power mobile communications systems, with particular emphasis on circuit and device performance. It is organized in the following manner. Section 4.2 outlines the advantages and disadvantages of silicon technology for applications to high-frequency low-power communications circuits. Section 4.3 summarizes the key device design aspects of SiGe devices, particularly with respect to high-frequency applications. Section 4.4 provides an assessment of passive component technology in Si/SiGe technology. Section 4.5 provides a direct comparison of the performance of silicon-based HBTs to those based on III-V technologies. Finally, Section 4.6 provides an overview of reported circuit performance in Si/SiGe HBT technology, with emphasis on low-power communications applications. [ABSTRACT FROM PUBLISHER]

This chapter describes a series of novel concepts to increase microwave power amplifier efficiency. Within modern wireless systems, power amplifiers must meet exacting linearity specifica-tions, which tend to be at odds with the need for high efficiency. To characterize these specifications and associated trade-offs, the authors first review the linearity requirements and dynamic range requirements of representative high performance communication systems. They then demonstrate concepts for power amplifier improvement that can meet the system requirements. [ABSTRACT FROM PUBLISHER]

Following a brief overview of the basic constructing elements for modern planar microwave/millimeter-wave passive circuits, this chapter presents two innovative approaches to meet the above-mentioned technical challenges of high-Q passive components for high-frequency applications. The first approach, based on a unique process named SIMPOL (silicon/metal/polyimide), aims at realizing low-loss, high-isolation interconnects and passive components on low-resistivity, CMOS-grade silicon substrates. The second approach for high-Q passive components is based on the photonic bandgap (PBG) concept. These are basically periodic structures that can be used to control the propagation, reflection, or radiation of electromagnetic waves in a slightly different way compared to conventional waveguiding or filtering techniques. [ABSTRACT FROM PUBLISHER]

Chapter 9 deals with the phenomenon of non-linear amplification of synchronous CDMA signals. This phenomenon appears at the satellite amplifier for down-link transmission. Performance analysis provides the optimum value of the input 'back-off' required for linear amplification. [ABSTRACT FROM PUBLISHER]

This chapter gives the most detailed analysis and guidelines for discrete and integrated amplifiers, providing deep insight into semiconductor performance and circuitry necessary to get the best results from the devices. It includes a discussion of the properties of the amplifiers, gain stability, and matching, and an evaluation of one-, two-, and three-stage amplifiers with internal dc coupling and feedback, as are frequently found in integrated circuits. Examples of ICs currently on the market, are also provided. Another important topic in this chapter is the choice of bias point and matching for digital signal handling, and insight into such complex issues as the adjacent channel power ratio. A discussion of differential amplifiers, frequency doublers, AGC, biasing and push-pull/parallel amplifiers comes next, followed by an in-depth section on power amplifiers, including several practical examples and an investigation of amplifier stability analysis. A selection of power-amplifier datasheets and manufacturer-recommended applications completes the chapter. [ABSTRACT FROM PUBLISHER]

Chapter 10 deals with the techniques available for the mitigation of multipath effects. There is an extensive discussion of diversity reception including: Diversity methods; Improvements obtainable from diversity; The effect on data systems; Practical diversity systems; Post-detection diversity; Time diversity; Diversity on handportables; Other techniques that are described include: Interleaving; Channel equalisation - adaptive and non-linear equalisers; Channel coding; Speech coding; The RAKE receiver; Smart antennas; Wideband modulation and mitigation bandwidth. [ABSTRACT FROM PUBLISHER]

Chapter 9 deals with man-made noise and interference. It covers: The characterisation of pulses and impulsive noise; Measurement parameters for impulsive noise including Amplitude Probability Distribution (APD) and Noise Amplitude Distribution (NAD); Specifications for noise-measuring equipment; Practical equipment for measuring APD and NAD; Impulsive noise measurements in urban and suburban environments; Assessment of receiver performance for analogue and digital signals using APD and NAD; Interference in radio systems, protection ratio and grade of service; Single and Multiple interferers. [ABSTRACT FROM PUBLISHER]

Chapter 7 is devoted to a discussion of the propagation of narrowband and wideband signals in other important mobile radio scenarios such as from outside to inside buildings and totally within buildings. Narrowband and wideband signals are considered. Ray tracing is introduced as a deterministic approach to a problem that has hitherto been tackled mainly by a statistical approach. The chapter also covers: The characterisation of pulses and impulsive noise; Measurement parameters for impulsive noise including Amplitude Probability Distribution (APD) and Noise Amplitude Distribution (NAD) Specifications for noise-measuring equipment; Practical equipment for measuring APD and NAD; Impulsive noise measurements in urban and suburban environments; Assessment of receiver performance for analogue and digital signals using APD and NAD; Interference in radio systems, protection ratio and grade of service; Single and Multiple interferers. [ABSTRACT FROM PUBLISHER]

The airlink subsystem is defined as the span between the user host's connection point and the subscriber unit. It includes the service provider's message switch/area controller, base stations, and the radio modem. There are at least four current philosophical control approaches: (1) decentralized, (2) partially decentralized, (3) partially centralized, and (4) centralized. Each of these approaches is examined in order, from highly decentralized to highly centralized. [ABSTRACT FROM PUBLISHER]

The variety of public network choices cited in the preceding chapter leads some potential users to despair at what seems a plethora of alternatives. Actually, specific user requirements can quickly eliminate many network candidates. This permits a more straightforward assessment of realistic alternatives. A few of those salient user characteristics are discussed in this chapter. [ABSTRACT FROM PUBLISHER]

Packet systems are the least uniform and most complex. Examples of the enormous range of products are presented in this chapter, in increasing degrees of complexity, beginning with the client modem and working through servers and gateways to the host application. [ABSTRACT FROM PUBLISHER]

This chapter deals with special loops that are basically one-loop synthesizers. There is a conflict between speed and step size, and the author details ways of minimizing this conflict. Multiloop sampler loops are explained, and it is shown how a delay line can be used to improve noise performance. It concludes with a description of the fractional N phase-locked loop, a spin-off of the digiphase system. [ABSTRACT FROM PUBLISHER]