VDSL Vs DSL

Digital Subscriber Lines, or DSL, transfers data over the twisted-pair copper lines used to transfer analog phone signals. Speeds of 1.5 Mbs to 20 Mbs are common. The installed base of phone lines makes DSL a highly available option. DSL lines are distance-limited by the strength of electrical signal. Theoretically, 15,000 feet is obtainable, though distances of 10,000 feet or less is generally required to achieve high throughput speeds. The distance from DSL hubs limits availability in rural areas.

Very High Speed Digital Subscriber Lines, or VDSL, utilizes high transmission rates over short distances on fiber-optic cable. Speeds of between 50 Mbs and 60 Mbs per fiber loop is achievable. While the speeds of VDSL lines provide sufficient bandwidth to support high-definition television, the sharing of bandwidth on individual loops limits the practice. Installation of fiber-optic cable costs substantially more than copper wire, restricting the placement of individual loops for small numbers of users.

DSL is primarily available in highly populated areas, with some rural areas receiving reduced bandwidth service. Most metropolitan areas support DSL to residences and business. VDSL requires installation of new technology. The installation costs, time required to build the infrastructure and limited demands have restricted the availability of VDSL to select metropolitan areas by major carriers. Qwest, AT&T; -- under the trade name "U-Verse" -- and Verizon provide VDSL services. Market availability is determined by both demand and technological availability.

At time of publication, residential DSL monthly costs average approximately $20 for basic service, to $60 for ultra-high-speed residential DSL service. VDSL monthly service typically includes television broadcasting as well as internet connectivity and begins at around $100.