Overview

In previous chapters, we have explored the use of optical networks for metro and long-haul network applications. The access network is the last leg of the telecommunications network that runs from the service provider s facility to the home or business. With fiber now directly available to many office buildings in metropolitan areas, networks based on SONET/SDH or Ethernet-based technologies are being used to provide high-speed access to large business users. Business users are big consumers of data services, many of which are delivered in the form of leased lines at various speeds ranging from 1.5 Mb/s to several gigabits per second. While this is happening, the telephone and cable companies are also placing a significant emphasis on the development of networks that will allow them to provide a variety of services to individual homes and small to medium businesses. This is the focus of this chapter.

Today, homes get essentially two types of services: plain old telephone service (POTS) over the telephone network and broadcast analog video over the cable network. Recently added to this mix are data services for Internet access using either digital subscriber line (DSL) technology over the telephone network or cable modem service over the cable network.

Early efforts on developing high-capacity access networks were devoted to developing networks that would accommodate various forms of video, such as video-on-demand and high-definition television. However, the range of services that users are expected to demand in the future is vast and unpredictable. Today, end users are interested...