science

Nortel payphones

Nortel payphones 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 Nortel payphones rather than just read about it. In short: Northern Telecom (from 1998 known as Nortel) manufactured several different payphone models. They were most commonly used in Canada and the United States.

Key takeaways

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

Reference excerpt

Northern Telecom (from 1998 known as Nortel) manufactured several different payphone models. They were most commonly used in Canada and the United States. Nortel has manufactured several types in Canada.

Early payphones N213H-3 N233H

Series 200/ QSD-3A Northern Electric, Nortel's previous name made chrome payphones in the 1950s. The same phone was also made by Western Electric.

Centurion

Nortel Centurion were made in the 1970s–1980s and used coins only. They came in black, brown, blue, or green cases. Initial units used a rotary dial system and later units were touch tone key pad. Coin slot accepted denominations of 5, 10 and 25 cents. Centurions had a coin return button. Centurion were used by Bell Canada, MTS, Telephone Milot and other local phone companies in Canada. Additionally, Centurions were used by companies in the United States such as Embarq, and a number of other independent telephone companies.

Millennium

The Millennium line was introduced in the 1990s and allowed the use of coins (5, 10, 25 cents and 1 dollar coins) and/or cards (credit card or phone cards as well as "smart" chip cards.) They were equipped with an advanced electronic coin validator, which could detect slugs or coin blockages. These units came with a touch tone key pad only. A display screen allowed the user to view the number dialed and switch between two languages, where the operating company has a choice of any combination of English, French, Spanish and Japanese. The VFD display also allows the operating company to set scrolling messages and ads, with a total of 20 messages possible in total, 10 for on hook and 10 for off hook, 20 characters each. Additionally, a message can be attached to each of the quick-dial buttons (if available). These units were or are still used by:

Bell Canada Bell Aliant Telus Qwest Sprint Sasktel Telebec Telephone de Nantes Telephone de Warwick US West Express GTE Nevada Bell Embarq Cooptel Century Telephone FSH Communications Millennium phones require a CO line with polarity reversal for CDR (call detail record) purposes, as well as for coin return, hence these phones have no coin return button. The rights to Millennium phones were sold to QuorTech when Nortel moved away from manufacturing phone devices, and were subsequently sold to WiMacTel. Quortech has all but disappeared from the public and in March 2014, WiMacTel announced they were the only operator of Millennium payphones in Canada and the US. The phones themselves are quite complex, using a Zilog Z180 processor with a number of peripherals attached. The whole point of the Millennium system was security and advanced monitoring. All Millennium phones connect to a server platform called Millennium Manager, which allows the operating company to control and monitor virtually every aspect of a phone. The phones 'call home' on a regular basis, uploading CDR records if they are full and reporting coinbox status (down to the amount of coins in a given denomination). The coin vault lock has a small micro switch that can detect break ins, which will cause the phone to call into the Millennium Manager with an alarm. The main housing lock also has a similar switch, which if triggered without entering the craft interface beforehand will trigger an alarm as well. A Mondex version of the payphone was also produced with a special larger display and navigation keys. There is also an inmate version of the card only set, as well as a smaller deskset that used only a card reader. The desk set closely resembled a regular Meridian M7310 office phone. These smaller sets were often found in malls and hospitals. The card readers were easily removed from the phone and often stolen and repurposed by hackers in systems like laundry machines and vending machines. Hackers found these readers could be adapted to a PC and then used to modify stored-value cards for small transactions, allowing them to bypass legitimate payment systems in various devices. This adaptability made the card readers a frequent target for theft and misuse. These phones can sometimes be found on eBay for relatively cheap, though one cannot do much with them without the connection to the Millennium Manager. There are a few active projects which are trying to solve this problem however.

Illustrations

Nortel payphones: N233H pay phone — N233H pay phone

Worked examples

Example 1 — a first encounter with Nortel payphones

Start with the simplest possible case. Write down what Nortel payphones 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 Nortel payphones 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 Nortel payphones 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 Nortel payphones

In research: Nortel payphones 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 Nortel payphones 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: Nortel payphones is common in secondary-school and first-year university syllabi. It links to neighbouring topics Nortel, Nortel telephones, Public phones, so understanding it makes those chapters shorter.
In everyday life: Look for Nortel payphones 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 Nortel payphones in 20 minutes

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

Frequently asked questions

What is Nortel payphones in simple terms?

Northern Telecom (from 1998 known as Nortel) manufactured several different payphone models. They were most commonly used in Canada and the United States.

Why does Nortel payphones 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 Nortel payphones?

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 Nortel payphones.