d in more detail in Chapter 8. End Notes 1. You can also carry a non-SONET framed signal; however, the majority of systems now deployed are used as adjuncts to SONET-namely, they carry a SONET signal. 2. It is also possible to pack both a send and a receive signal onto a single strand, but most telecom systems utilize a fiber pair. Dense Wavelength Division Multiplexing (DWDM) Systems 3. The methodologies embodied in these trade-off considerations are really no different from the trade-off considerations of the 1950s when contemplating the deployment of a 12-channel analog loop carrier as contrasted with the deployment of 12 distinct analog loops, or from considerations in the 1970s when contemplating the deployment of a 24-channel digital loop carrier as contrasted with the deployment of 24 distinct (analog) loops. 4. For example, note this quote from J. McQuillan, "Broadband Networking at the Crossroad," NGN 2001 Promotional Materials, October 11, 2001: "Ten years of price competition in voice have been compressed into three years for Internet prices. And price erosion is accelerating: A contract for an OC-3 from New York to Los Angeles for the year 2002 dropped in price by 92 percent in just four months." 5. T1 and T2 systems have been more predominant in the loop environment than T3 systems; however, with the introduction of fiber- based feeder systems, particularly the Bell System/Lucent SLC-96 system, an increasing number of DS3 systems (originally called FT3) have been deployed in support of loop applications. 6. Refer to Bellcore, Telecommunications Transmission Engineering, ISBN 1-878108-04-2 (1990): 396 ff. 7. www.cir-inc.com/index.cfm?loc=news/view&id=85 Excerpting from the November 2001 report by Communications Industry Researchers, Inc. (CIR) titled "Metro Optical Networking Market Opportunities," which states Are we there yet? For close to five years, the metro DWDM market has failed to fulfill the vaunted promises of significant growth opportunities. CIR's research prognosticates that 2003 will be 