 Seven Fiber Services (MFS), which is now part of Worldcom Communica- tions. Today there are literally over 100 CLECs providing a bypass of the local telephone company; however, because it is expensive to pro- vide connectivity to a building, the primary focus is on installing a fiber loop that provides connectivity to office buildings that may have hundreds to thousands of workers. While the derogatory term "cherry picking" is used to infer that the bypass provides access only to larger customers in terms of billing, it also explains why bypass "bypasses" smaller buildings and homes where the cost of providing service would be higher than any expected profit from providing the service. Unlike the local telephone company that must provide universal ser- vice, there is no such requirement for bypass operators. Thus, they are free to select large revenue sources and bypass the small consumer, which explains why FTTH including fiber being routed into office buildings and apartment buildings is not expected to significantly increase its penetration rate before the year 2006 or SO. Team-Fly® CHAPTER Fiber in the Building Chapter Eight Until this chapter our primary focus concerning optical equipment was either on distinct components, such as lasers, LEDs, and photode- tectors, or devices used in a LAN or WAN environment. In this chap- ter we focus on fiber in the building, examining the operation and utilization of such products as the fiber modem, fiber multiplexer, and even an optical mode converter. Although a local area network is obviously a network facility installed primarily within a building, this topic is not covered in this chapter. Instead, LANs were covered as a separate entity in Chapter 5 when we examined fiber in the LAN. Thus, the primary focus of this chapter is on the use of optical fiber and equipment used within a building primarily to obtain a trans- mission capacity extending beyond that provided by conventional copper cable. Fiber-Optic Modems Any communications system requires a transmitter, a