e-sensitive, the use of fiber provides telephone companies with a mechanism to increase the transmission rate that subscribers can obtain. In addition, the routing of fiber permits neighborhoods that would be normally too distant from a central office for DSL services via copper twisted-pair cabling to obtain the ability to be eligible for DSL services. The Evolving Cable TV Infrastructure In this section we discuss the evolving CATV infrastructure. We will also note how the development of the Internet and its access via cable modems required a major revision of 45-year-old (at the time of writing) network architecture. Overview Although early cable television systems were developed during the late 1940s as a mechanism to improve reception in rural areas, through the Fiber in the Neighborhood mid-1990s the architecture remained relatively stable. Commencing in the mid-1990s, the growth in the use of the Internet and its graphics- intensive Web pages provided the foundation for the development of a variety of broadband access techniques, including cable modems. In comparison to the telephone network infrastructure, where DSL represents a nonshared, point-to-point technology, the transmission of data over a CATV infrastructure occurs on a shared-network basis. In this arrangement, one or more branches in the network may be config- ured to support the shared use of two TV channels for the transmission of data on a branch or series of branches to and from groups of sub- scribers. Thus, one channel is used for transmission in the downstream direction while the second channel is used for transmission in the uplink direction. Similar to most flavors of DSL, the operation of a cable modem repre- sents an asymmetrical transmission method. In the upstream direction, a data transmission rate between 640 kbits/s and 10.24 Mbits/s is sup- ported in accordance with the method of modulation used as specified by a standard referred to as Data Over Cable System Interface Specification (DOCSIS). In contrast, in the downstream dire