The Hype of DSLTechnologies

The local providers are extremely excited at the possibility of installing higher speed communications and preserving their local cable plants. No one wants to abandon the local copper loop, but getting more data reliably across the local loop is imperative.

Therefore, the ability to breathe new life into the cable plant is an extension of the facilities in place. This also means that they can create a new form of revenue streams from the old copper. Consumers are looking for high-speed access (primarily to access the Internet) for whatever the application.

Yet, at the same time, consumers are looking for a bargain. They do not want to spend a lot of money on their communications services.

The providers are trying to bump up their revenues, with out major new investments. They would like to launch as many new service offerings on their existing cable plant and increase the costs to the end user.

This is a business decision, not a means of trying to rake the consumer over the coals.Yet, a happy medium must be found of providing services and generating revenues with limits on expenses.

To do this, the xDSL family offers the opportunity to meet the demands while holding down investment costs. The key ingredient for success is to minimize costs and satisfy the consumer. Make no mistake—if the local provider does not offer high-speed services, someone else will.

xDSL Coding Techniques

Many approaches were developed as a means of encoding data onto xDSL circuits. The more common are carrier less amplitude phase (CAP) modulation and discreet multitone (DMT) modulation. Quadrature phase modulation (QAM) has also been used, but the important part is the standardization. The industry as a rule selected DMT, but several developers and providers have used CAP.It is therefore appropriate to summarize both of these techniques.