science

Payphone

Payphone 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 Payphone rather than just read about it. In short: A payphone (alternative spelling: pay phone or pay telephone or public phone) is typically a coin-operated public telephone, often located in a telephone booth or in high-traffic public areas. Prepayment is required by inserting coins or telephone tokens, swiping a credit or debit card, or using a telephone card.

Key takeaways

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

Reference excerpt

A payphone (alternative spelling: pay phone or pay telephone or public phone) is typically a coin-operated public telephone, often located in a telephone booth or in high-traffic public areas. Prepayment is required by inserting coins or telephone tokens, swiping a credit or debit card, or using a telephone card. The company that operates the payphone generally pays either rent or a revenue share to the owner of the property where the phone is installed. Invented in the late 19th century, payphones became ubiquitous worldwide in the 20th, enough to contribute to the notion of universal access to basic communication services. The charge for a call may be a flat rate, or dependent on call duration. Following the explosive growth of mobile telephony, the use of payphones, and the number installed, has decreased greatly; several countries and areas have now abolished their payphone services altogether.

Countries

Australia As of 2017, in Australia, there are approximately 17,000 payphones. Previously, there had been over 30,000 payphones. In Australia, Telstra operates 15,000 payphones, which have been available free of charge as of 2021. Telstra had previously made payphones available for free at Christmas and the New Year. The number of payphones Telstra operates is determined by the Australian federal government. Telstra has a universal service contract to provide payphones, which was criticized by ABC News for failing to secure mobile phones in February 2024 after a severe storm destroyed houses and shut down power and communications in Mirboo North. In 2017, the Australian government considered abolishing the payphone network.

Canada

Most payphones in Canada are owned and operated by large telecom providers such as Bell, Telus Communications, and SaskTel. In the last 20 years, customer-owned coin-operated telephones (COCOT) have also appeared in the market, but their numbers are smaller due to the emergence of mobile phones. The cost of most local payphone calls is 50 cents CAD, having increased from 25 cents since 2007. Payphones in Alberta were 35 cents for a time, but in most jurisdictions the price simply doubled. Newer phones allow users to use calling cards and credit cards. For coin-paid long distance, COCOTs are less expensive for short calls (typically $1 for three minutes) than incumbent providers (whose rates start near $5 for the first minute). Dialing 0 for the operator and 911 calls are still free. The Toronto Transit Commission deploys payphones on all subway platforms as a safety precaution; a blue "Crisis Link" button on 141 payphones connects directly with Distress Centres of Canada as a free suicide prevention measure. As of 2013, there were about 70,000 payphones across the country. In 2013, the CRTC issued a temporary moratorium on the removal of payphones in small communities. In September 2015, the CRTC remarked that "32 percent of Canadians used a payphone at least once in the past year," and that they are used "as a last resort in times of inconvenience and emergency."

Germany The payphone model 23, introduced at Deutsche Bundespost Telekom in 1992, is an electronic software-controlled payphone for analog connections. It is equipped with coin, (German: Münzspeicherwagen), and integrated test program setting. It has a remote maintenance – the independent reports of a background system by means of an integrated modem error (for example, defects in components, lack of listeners), operating states (for example, full coin box), or departures (for example standing open the cartridge mounting door, missing coin). The Payphone 23 consists of two basic units, the equipment part including all the necessary for the operation modules (BG) and the secured below the growing payphone cassettes with the coin box.

Hong Kong

In Hong Kong, public payphones have been installed and maintained over the years primarily by HKT (formerly PCCW). Many public telephones were removed throughout the 2010s and early 2020s due to low usage, but thousands of physical kiosks still remain across the territory. Following structural changes in the telecommunications market and a decision by the Office of the Communications Authority (OFCA) to reduce subsidies, operators are no longer obligated to maintain public telephones in areas with low demand. However, the provision of communication services remains highly visible in specific public infrastructure, with free courtesy phones consistently maintained throughout the Hong Kong International Airport.

Italy In Italy, public payphones have been installed and maintained over the years by Telecom Italia (formerly SIP). Many public telephones were removed in the early 2010s, but there are still several thousand in operation throughout Italy. From 26 May 2023, following an AGCOM decision, TIM-Telecom Italia is no longer obliged to keep public telephones in service (but still has the option to do so). In hospitals, prisons, barracks and mountain refuges, the provision of public telephone services is in any case mandatory.

Japan

The majority of payphones on the street and in buildings in Japan are installed and maintained by Nippon Telegraph and Telephone (NTT).

Russia

In the Soviet period, different types of payphones were produced. There were also long-distance call payphones costing 15 kopeks, and also provided services of paid media such as listening to an anecdote, obtaining legal advice, or finding the address of the subscriber by phone number. After the collapse of the Soviet Union and the monetary reform of 1991, this form of payment became irrelevant. Some payphones were altered to accept tokens, while others have been designed to use telephone cards. For example, in St Petersburg, payment for payphones can be made with metro tokens. In some regions, calls from public phones are free of charge.

… excerpt ends here. Continue reading the full article.

Illustrations

Worked examples

Example 1 — a first encounter with Payphone

Start with the simplest possible case. Write down what Payphone 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 Payphone 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 Payphone 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 Payphone

In research: Payphone 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 Payphone 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: Payphone is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1889 introductions, 19th-century inventions, American inventions, so understanding it makes those chapters shorter.
In everyday life: Look for Payphone 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 Payphone in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Payphone 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 Payphone out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Payphone in simple terms?

Why does Payphone 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 Payphone?

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 Payphone.