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Naked DSL

Naked DSL is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Naked DSL rather than just read about it. In short: A naked DSL, also known as standalone or dry loop DSL, is a digital subscriber line (DSL) without a PSTN (analogue telephony) service — or the associated dial tone. In other words, only a standalone DSL Internet service is provided on the local loop.

Key takeaways

  • Naked DSL belongs to science; place it in that map before memorising details.
  • Learn the definition first, then one example that makes the definition concrete.
  • Connect Naked DSL to a quantity you can measure, compute or draw — that is where exam questions come from.
  • Reproduce the core statement of Naked DSL from memory before moving on to harder problems.

Reference excerpt

A naked DSL, also known as standalone or dry loop DSL, is a digital subscriber line (DSL) without a PSTN (analogue telephony) service — or the associated dial tone. In other words, only a standalone DSL Internet service is provided on the local loop. The original concept of DSL was to use existing telephone lines for high speed data communication, with DSL and telephone services coexisting on the same phone line - but increasingly customers may require only the Internet service - and see no need for the traditional phone service.

Comparison of Regular and Naked DSL (Standalone DSL) In Regular DSL, data transmission is carried on inaudible high frequencies on a standard Plain Old Telephone Service (POTS) telephone line. The original idea was to use existing telephone lines for high speed data communication. DSL and telephone service can coexist on the same phone line and do not interfere with each other. From the Telco's point of view, DSL gives them the ability to sell the same telephone line twice, to the same customer. It is an idea that benefits the telco (who makes more money) and the customer (who gets a high speed data connection without the need for installation of expensive new cables.) Naked DSL is the same as standard DSL, except that there is no voice service. Telephone service is not required for DSL to operate correctly. The primary advantage of Naked DSL is financial: the customer saves the expense of a phone line, which they may not need. In terms of equipment, physical setup and speed, there is no difference between Naked DSL and Regular DSL. They are identical, except for the absence of dial tone. Telco Response to standalone DSL has generally been hostile. In the United States AT&T allows Standalone DSL for its own customers, but only very reluctantly, and it blocks third parties from providing Standalone DSL over AT&T telephone lines unless those customers also purchase AT&T branded voice services. Verizon stopped permitting Standalone DSL for its own customers in 2014, but some third parties such as Brand X Internet do still offer it. Verizon's own customers are required to buy Verizon branded voice services in order to purchase any kind of DSL. In regular DSL, a cable runs from the telephone switch to a piece of equipment called a Plain Old Telephone Service (POTS) splitter. This splitter separates the DSL and voice bands. Thus the customer will have a dial tone, which allows them to use the telephone line as a regular land line while they are using it to access the Internet on their computer. A cable carrying both services runs from the splitter to the cable head, where it continues on to the customer on outside plant. (See DSLAM.) In naked DSL, there is no cable from the telephone switch to the POTS splitter. Thus there is no dial tone on the line. However, the customer could still use the line for regular telephone service through Voice over Internet Protocol (VoIP) or a Competitive Local Exchange Carrier (CLEC) instead of the Incumbent Local Exchange Carrier (ILEC). Naked ADSL2 and ADSL2+ provisioned with "all digital mode" Annex I or Annex J can achieve additional 256 kbit/s of upstream data rate.

Availability Naked DSL is available in several countries, if not nationwide then via at least one company: Austria, Australia, Belgium, Bulgaria, Canada, Croatia, Denmark, Estonia, France, Germany, Israel, Italy, the Netherlands, New Zealand, Norway, Philippines, Portugal, Sweden, Switzerland, Turkey and the United States.

Australia Amnet was the first ISP in Australia to officially launch a naked DSL product live on 14 November 2007, followed by iiNet a day later. Exetel released naked ADSL2 Services on 1 December 2007. Optus, Australia's second largest telecommunications provider, announced on 2 Mar 2009 that it will also be providing naked DSL services. Other providers include offer Naked DSL are listed at Updated List of Naked DSL ISPs that service Australia. Many of the smaller players use Optus to deliver their Naked DSL services.

Canada Since the CRTC ruling of 21 July 2003, Naked DSL service has been made available in Canada. Bell Canada and other incumbents typically charge an additional fee for dry loop DSL based on the "Band Rate" of the area (ranging from Band A to Band G) to consumers and smaller ISP's who use Bell's phone line.

Croatia Several providers offer naked DSL, but as of late July 2012, Iskon Internet is the first one to offer naked DSL nationwide on T-Hrvatski Telekom's existing infrastructure, by unsubscribing from T-Com's analog line and providing telephony service over VoIP. However, due to T-HT's wholesale policy and prices, higher speeds would be too expensive for end user, and DSL link still operates in Annex B.

Denmark Naked DSL is available from the majority of ISPs, as most ISPs have now converted to VoIP solutions. Having 2 different providers for both POTS and DSL is possible.

France Several ISPs now offer Naked Unbundled DSL services, which are also called offres dégroupées. ISPs generally supply their own DSL modem with an FXS (Foreign exchange station) port for a standard phone handset and a set top box to provide television services. The first ISP to offer Naked DSL was Free with their Freebox.

Germany At least one ISP offers Naked DSL service: M-Net and its version, Maxi Pur.

Israel Naked DSL (both ADSL and VDSL) is provided by Bezeq telephony company to customers upon request, since most homes use both telephony and DSL lines as default, the service is provided only by demand. It's possible to request to remove the telephony line function at any given time without any restrictions or obligations.

New Zealand Chorus Limited is the wholesale provider for the vast majority of phone lines and it provides naked DSL services. All the major internet retailers provide a naked DSL service. It is possible to get the POTS and DSL from different service providers. As of December 2013, Chorus provides 1.091 million ADSL2+ connections, of which 98,000 (9%) are naked, and it has 25,000 VDSL2 connections, of which 5,000 (20%) are naked.

Paraguay Naked DSL service is available in Paraguay from State owned COPACO

Philippines Bayan Telecommunications, Globe Telecom, EASTERN Communications, and Smart Telecommunications offers that service.

… excerpt ends here. Continue reading the full article.

Worked examples

Example 1 — a first encounter with Naked DSL

Start with the simplest possible case. Write down what Naked DSL claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Naked DSL before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Naked DSL ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Naked DSL

In research
Naked DSL appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry
Engineering practice reuses Naked DSL in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom
Naked DSL is common in secondary-school and first-year university syllabi. It links to neighbouring topics Digital subscriber line, so understanding it makes those chapters shorter.
In everyday life
Look for Naked DSL outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.
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How to study Naked DSL in 20 minutes

  1. Read the reference excerpt below once, without taking notes.
  2. Close the page and write down what Naked DSL means in your own words.
  3. Compare your version with the excerpt and mark what you missed.
  4. Work through the three examples above with pen and paper.
  5. Explain Naked DSL out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Naked DSL in simple terms?

A naked DSL, also known as standalone or dry loop DSL, is a digital subscriber line (DSL) without a PSTN (analogue telephony) service — or the associated dial tone. In other words, only a standalone DSL Internet service is provided on the local loop.

Why does Naked DSL matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Naked DSL?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Naked DSL.

Tags

  • Digital subscriber line

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