DSL (Digital Subscriber Line or Digital Subscriber Loop. A technology that enables high-speed transmission of digital data over regular copper telephone lines. DSL works by using more of the capacity of the phone line. Voice and traditional modems work by modulating a signal in a limited range of frequencies (thousands of cycles); broadband sends a digital signal over a wide frequency (millions of cycles). The accelerated growth of content rich applications and online gaming, which demand high bandwidth, has changed the nature of information networks. High-speed communication is now an ordinary requirement throughout business, government, academic, and home office environments. Internet access, telecommuting, and remote LAN access are three of the clearly defined services that network access providers are offering now. These rapidly growing applications are placing a new level of demand on the telephone infrastructure. In particular, the local loop portion of the network (i.e., the local connection from the subscriber to the local central office) has become a challenge for telephone companies. Historically, this local loop facility has been provisioned with copper cabling which cannot easily support high bandwidth transmission. This environment is now being stressed by the demand for increasingly higher bandwidth capacities. Although this infrastructure could be replaced by a massive rollout of fiber technologies, the cost to do so would be insupportable in today's business models and, more importantly, the time to accomplish such a transition is unacceptable because the market demand exists today! Telephone companies are already faced with growing competition and unprecedented customer demands a new category of companies, Internet Service Providers (ISPs), has emerged in this market as providers of data services. Traditionally ISPs have used the telephone company infrastructure. However, thanks to deregulation, they now have direct...
