What is 'Asymmetric Digital Subscriber Line - ADSL'

Asymmetric Digital Subscriber Line (ADSL) is a new technology that provides high transmission speeds for video and voice to homes over ordinary copper telephone wire. It will be most cost-effective in areas with a low market penetration of cable TV.

BREAKING DOWN 'Asymmetric Digital Subscriber Line - ADSL'

Asymmetric Digital Subscriber Line (ADSL), sometimes just called DSL, is considered to be the major competition to cable modems. DSL and cable systems are compared by bandwidth, a measure of how much data a network can transfer. Internet providers typically denote bandwidth speeds in millions of bits per second, or megabits (Mbps), and billions of bits per second, or gigabits (Gbps). Generally speaking, the higher the bandwidth, the faster the speed with which a computer downloads information from the internet whether users view emails or watch streamed movies.

The U.S. Federal Communications Commission (FCC) defines broadband internet speeds as connections with a bandwidth of 25 Mbps for downloads and 3 Mbps for uploads.

Providers state the bandwidth measurement to customers, but that may not be the actual bandwidth speed a customer receives. The connection could have a bottleneck where one network is limited by the lowest speed going to several computers at once. More computers connected to the same bandwidth speed can slow down the bandwidth for everyone who shares the same connection.

Cable vs. Internet vs. Fios

In terms of theoretical peak performance, a cable modem generally has greater bandwidth than DSL. Cable technology, which transmits data over coaxial copper cables buried underground originally intended for television, currently supports approximately 300 Mbps of bandwidth in many areas, while DSL speeds typically peak at 100 Mbps. Actual speeds can vary in practice depending on the quality of the copper phone line installation. In addition, the length of the phone line needed to reach the service provider's central office also can limit the maximum speed a DSL installation can support.

In 2017, Verizon Communications Inc. (VZ) introduced a new service, Fios Instant Internet, that increased the internet speeds it offers to both residential and business customers, The broadband service provides customers with equal upload and download speeds of 750 Mbps. Verizon claimed that with symmetrical speeds, the new service could handle multiple devices connected to the internet without compromising the performance of any of them.

Most types of DSL service are asymmetric, or ADSL. Typically, ADSL offers higher download speeds than upload speeds, which is usually not a disadvantage because most households download more data from the internet than they upload. Symmetric DSL maintains equal data rates for both uploads and downloads.

The main selling point of DSL is widespread availability; telephone infrastructure is already deployed basically everywhere, so it doesn’t take much setup to connect most customers to the internet via DSL, especially in rural areas where cable is less likely to be an option.

RELATED TERMS
  1. Speed Resistance Lines

    Speed resistance lines are a tool in technical analysis that ...
  2. Asymmetric Information

    Asymmetric information occurs when one party to a transaction ...
  3. Asymmetric Volatility Phenomenon ...

    The asymmetric volatility phenomenon is the observed tendency ...
  4. Dealer-Median Prepayment Speed

    Dealer-median prepayment speed is the median of all securities ...
  5. Telephone Bond

    Telephone bonds are debt obligations issued by telephone or telecommunication ...
  6. Cloud Computing

    Cloud computing is a model for delivering information technology ...
Related Articles
  1. Investing

    Bandwidth Surges After Its First Public Report

    Bandwidth (NASDAQ: BAND) shares surged 16% during after-hours trading on Wednesday after the cloud communications platform provider reported third-quarter earnings -- its first public report ...
  2. Managing Wealth

    The Real Cost Of A Speeding Ticket

    Speeding can come at a cost that goes well beyond one driver and one ticket.
  3. Investing

    4 Things to Watch in the Cable Industry's Consolidation

    Learn about the high-profile purchases being made of cable companies and how these signal the future consolidation of the cable industry.
  4. Small Business

    5 Reasons The Cable TV Industry Is Dying

    The demise of cable TV has been written about for many years but cable continues to hang on. This article discussed why cable is faced with these issues.
  5. Investing

    The Very Cheapest Ways to Get Phone Service

    From landlines to bundled service to VoIPs and MVNOs, there are more inexpensive options than ever. Here's a rundown.
  6. Personal Finance

    5 Ways To Cut Your Cable Bill

    The cost of cable keeps climbing, but that doesn't mean you have to pay more satisfy your TV cravings.
  7. Insights

    Google and Facebook to Build an Undersea Cable Between LA and Hong Kong (GOOG, FB)

    The Pacific Light Cable Network (PLCN) will be the highest capacity trans-Pacific route with 12,800 km of fiber and an estimated cable capacity of 120 terabits per second (or, the capacity to ...
  8. Investing

    Frontier Communications Keeps Losing Subscribers

    At a time when most cable and internet providers have been shedding pay-television customers, but making up the lost revenue with broadband subscribers, Frontier Communications (NASDAQ: FTR) ...
  9. Investing

    China Vs. The U.S.: A Race To The Top

    Wherever China does not have the lead already, it has embarked on virtually unprecedented efforts to get there.
  10. Trading

    Fundamental Speed: The "Duck-And-Jab" Approach To Forex

    By using economic releases in a timely way, buyers can beat the "big players" without endless chart analysis.
RELATED FAQS
  1. How do financial markets exhibit asymmetric information?

    Understand how financial markets exhibit asymmetric information and learn how asymmetric information by any party can result ... Read Answer >>
  2. How does government regulation impact the internet sector?

    Learn about the debate on how government regulation could affect the Internet sector and where Americans stand on Internet ... Read Answer >>
  3. What is the theory of asymmetric information in economics?

    Read a brief overview of asymmetric information theory in economics, the development of its main arguments and why some challenge ... Read Answer >>
  4. How does government regulation impact the telecommunications sector?

    Read about the many ways the U.S. government regulates the telecommunications industry, including radios, telephones, TV ... Read Answer >>
  5. What is the average price-to-earnings ratio in the internet sector?

    Learn what the average price-to-earnings (P/E) ratio is for companies in the internet sector and how the sector is broken ... Read Answer >>
  6. What factors affect the price of copper?

    Copper is the world's third-most-used metal (following iron and aluminum) because of its versatility and conductivity. Read Answer >>
Trading Center