Residential Broadband, Second Edition

xDSL Variations

DLCs represent the most recent innovation in telephone company access networks to consumers. However, DLCs do not provide high-speed services by themselves; they are just vehicles for providing legacy services more cost effectively. To provide high-speed services, whether through a DLC or directly connected to a central offices, new modulation, forward error correction, and loop installation steps are required.

While DLC has more or less been standardized among telephone companies, high-speed DSL services have been graced with a variety of services. In fact, one of the issues with xDSL services is that there are too many of them. This had led to market confusion, controversy, and fragmentation. xDSL has not coalesced around ...