Telecommunications Wiring,
3rd edition, USBN: 0-13-028696-6
Author: Clyde N. Herrick
Publisher: Prentice Hall PTR, 2001

A great number of people in the EMC community have become interested in telecommunications issues (e.g. wireless LAN, Bluetooth, etc.) due to the EMC and EMI implications. Though the telecommunication business has received a severe pounding in the stock market, the future still looks promising, in the long term, by any measure or standard you want to use. Therefore, it is of interest that we review telecommunications books that are either related or have implications to EMC/ EMI. The first of this type book we have chosen to review deals with telecommunications wiring. The purpose of this review is to introduce the concepts of telecommunications wiring to EMC engineers; there is a very good likelihood that one of the first EMI problems you may be asked to resolve has to do with wiring!

The book is composed of 15 chapters and it is written for those involved in the design and installation of wiring systems for telecommunication equipment. Therefore, the math is light and the amount of illustrations is large. It is easy reading, yet it is highly comprehensive and there is a lot of data put forward. The third edition was created to include digital subscriber line (DSL) technology, as well as current wiring and networking technology. Many books have been written on higher-level subjects in telecommunications such as local area networking, designing LANs, telecommunication systems, and so on. However, the cabling and wiring sections of such books seldom offer any practical information. The cabling should be treated as a "dynamic source"rather than a static one. From the EMC point of view, we know that wiring is dynamic.

Chapter 1 starts with the electrical characteristics of wire. A wiring system is a form of electrical circuit and it is treated as such. The concepts of resistance, inductance, signal to noise ratio, capacitance, and impedance of wiring circuits are discussed. Other EMC related concepts such as digital and analog grounding, cross-talk, and signal attenuation are also discussed. Chapter 2 is a natural progression from chapter 1 since it talks about transmission media, in particular the twisted pair. Twisted pair wiring is, and will be for years, the most often used telecommunications medium. A new driving technology is to use new techniques of transmission to maximize the transmission rate of twisted pairs. New inventions and new transmission techniques have increased the bandwidth capability of twisted pair far beyond what was thought the maximum a few years past. In this chapter, the two types of twisted pair wiring are described in detail: unshielded twisted pairs (UTP), and shielded twisted pairs (STP), together with the concept of cross-talk. A detailed discussion is made of the different applications of twisted pairs. Twisted pair terminations are covered in the chapter as well as the electrical characteristics of twisted pair cabling. The chapter ends with a discussion of flat/ribbon cabling and the tools used for installing twisted pairs.

Chapter 3 discusses coaxial cables. Coax is a time proven cabling medium that can be utilized in most audio/data communication systems and with most telecommunications devices. The additional expense of coaxial cable is usually justified over twisted pair cable if information security and signal bandwidth are important. The book follows the same approach, as used with twisted pairs, in the outline of chapter 3. The chapter also discusses the grounding of coaxial cables and the advantages/disadvantages of coaxial cables over twisted pairs. Chapter 4 is the last to address transmission media and it discusses fiber optics cabling. The chapter spends some time on the principles of fiber optics communications, but then it quickly jumps to address practical matters such as cable construction, cable terminations, specification of the type of fiber optic cable, installation, data rate issues, cable splicing (different types), and the advantages and disadvantages of fiber optics cabling. There is a need to balance the advantages of the three cable types against the cost of installation, cost of maintenance, availability, and future needs before selecting a cable type. Chapter 5 covers the National Electric Code (NEC) set of telecommunication wiring requirements, mostly geared to minimize hazards of electrical shocks, explosions, and fires caused by electrical wiring.

Chapter 6 starts with network topologies, which is really a short introduction to LAN. It covers the different types of network topologies such as BUS, STAR, and RING. Chapter 7 discusses DSL. DSL is a modem-like technology that allows the transmission of voice, video, and data over existing copper telephone lines at megabit speed. DSL provides dedicated bandwidth that is 143 times faster than a 56K modem, 62 times faster than ISDN, and 4 times faster than T1 connection.

From chapter 8 through chapter 15, the author takes the reader through every single step needed for the wiring of a telecommunications system. Chapter 8 starts with the premise that you need to plan for the installation process. It is important that planning and installation guidelines be established and adhered to whenever any major system needs to be installed, upgraded or removed. The chapter presents some of the most important aspects that must be addressed and the reasons behind them. Chapter 9 deals with the actual installation strategy of cabling. There are as many cable schemes as there are buildings. The building topology, the present inventory of data processing equipment, the current in-place wiring, and the future telecommunications plan will all dictate the type of network and wiring media employed. The wiring media and wiring methods should be tailored to the facility and the present and future needs of the business. EMC engineers must first become familiar with the wiring of the facility if an EMC problem is to be resolved. Chapter 10 covers premise wiring systems. Proper connectivity that allows for manageability, flexibility, versatility, and future expansion are needed in the design of the cable system. The cabling must support all logical configurations, such as point-to-point, bus, star, tree, and hybrid. Topics covered in this chapter include: fiber optics networks, commercial building telecommunication cabling standards, campus backbone, equipment rooms and network cabling, cabling architecture, centralized/distributed network architectures, and small business architectures.

Testing and troubleshooting and all the equipment needed for such endeavors are discussed in chapter 11. Testing, troubleshooting, and maintaining a communication system is an involved procedure that encompasses both hardware and software specialists. Some of the testing and troubleshooting can be accomplished by the use of a diagnostic software program. These functions of testing, troubleshooting, and maintaining fall in the lower level of system protocol. All the most common tests are described in the chapter. Documenting the wiring system is explained in chapter 12. Documentation of the cabling system is paramount for effective service to the user community and maintenance of the telecommunication system. Documentation should consist of all the information and data that would be necessary to understand and troubleshoot the system. EMC engineers are advised to look at the documentation in detail before attempting any fixing job. The goal of chapter 13 is to outline the requirements of a telecommunications database and give an example of one such system. A brief discussion on how to manage wiring problems is shown in chapter 14. The final chapter in the book, chapter 15, provides specifications on how to write a bid proposal for the installation of a wiring system for telecommunication equipment.

I found this book useful for those EMC engineers who want to be involved in the telecommunications industry. EMC