rk, how much loss is inserted for interLATA connections? REFERENCES 1. International Telephone Routing Plan, CCITT Rec. E.171, Vol. II, Fascicle II.2, IXth Plenary Assembly, Melbourne, 1988. 2. The Transmission Plan, ITU-T Rec. G.101, ITU Geneva, 1994. 3. Traffic Routing, CCITT Rec. E.170, ITU Geneva, 1992. 4. BOC Notes on the LEC Networks-1994, Special Report SR-TSV-002275, Issue 2, Bellcore, Piscataway, NJ, 1994. 5. Influence of National Systems on Stability and Talker Echo in International Connections, ITU-T Rec. G.122, ITU Geneva, 1993. 6. Control of Talker Echo, ITU-T Rec. G.131, ITU Geneva, 1996. 7. Terms and Definitions, CCITT Rec. B.13, Fascicle I.3, IXth Plenary Assembly, Melbourne, 1988. CONCEPTS IN TRANSMISSION TRANSPORT 9.1 OBJECTIVE A telecommunication network consists of customer premise equipment (CPE), switch- ing nodes, and transmission links as illustrated in Figure 9.1. Chapter 5 dealt with one important type of CPE, namely the telephone subset. The chapter also covered wire- pair connectivity from the telephone subset to the local serving switch over a subscriber loop. Basic concepts of switching were reviewed in Chapter 4, and Chapter 6 covered digital switching. In this chapter we introduce the essential aspects for the design of long-distance links. There are four different ways by which we can convey signals from one switching node to another: 1. Radio 2. Fiber optics 3. Coaxial cable 4. Wire pair Emphasis will be on radio and fiber optics. The use of coaxial cable for this application is deprecated. However, it was widely employed from about 1960 to 1985 including some very-high-capacity systems. One such system (L5) crossed the United States from coast to coast with a capacity in excess of 100,000 simultaneous full-duplex voice channels Figure 9.1 A telecommunication network consists of customer premise equipment (CPE), switching nodes, and interconnecting transmission links. Fundamentals of Telecommunications, Second Edition, by Roger L. Freeman ISBN 0-471-71045-8 Copyright © 2005 by Ro