Portal:Telephones
File:Candlestick-telephone icon.svg The Telephones Portal File:Smartphone icon - Noun Project 283536.svg
A telephone, colloquially referred to as a phone, is a telecommunications device that permits two or more users to conduct a conversation when they are too far apart to be easily heard directly. A telephone converts sound, typically and most efficiently the human voice, into electronic signals that are transmitted via cables and other communication channels to another telephone which reproduces the sound to the receiving user. The term is derived from Ancient Greek: τῆλε, romanized: tēle, lit. 'far' and φωνή (phōnē, voice), together meaning distant voice. In 1876, Alexander Graham Bell was the first to be granted a United States patent for a device that produced clearly intelligible replication of the human voice at a second device. This instrument was further developed by many others, and became rapidly indispensable in business, government, and in households. The essential elements of a telephone are a microphone (transmitter) to speak into and an earphone (receiver) which reproduces the voice at a distant location. The receiver and transmitter are usually built into a handset which is held up to the ear and mouth during conversation. The transmitter converts the sound waves to electrical signals which are sent through the telecommunications system to the receiving telephone, which converts the signals into audible sound in the receiver or sometimes a loudspeaker. Telephones permit transmission in both directions simultaneously. Most telephones also contain an alerting feature, such as a ringer or a visual indicator, to announce an incoming telephone call. Telephone calls are initiated most commonly with a keypad or dial, affixed to the telephone, to enter a telephone number, which is the address of the call recipient's telephone in the telecommunications system, but other methods existed in the early history of the telephone. The first telephones were directly connected to each other from one customer's office or residence to another customer's location. Being impractical beyond just a few customers, these systems were quickly replaced by manually operated centrally located switchboards. These exchanges were soon connected together, eventually forming an automated, worldwide public switched telephone network. For greater mobility, various radio systems were developed in the mid-20th century for transmission between mobile stations on ships and in automobiles. Handheld mobile phones were introduced for personal service starting in 1973. In later decades, the analog cellular system evolved into digital networks with greater capability and lower cost. Convergence in communication services has provided a broad spectrum of capabilities in cell phones, including mobile computing, giving rise to the smartphone, the dominant type of telephone in the world today. Modern telephones exist in various forms and are implemented through different systems, including fixed-line, cellular, satellite, and Internet-based devices, all of which are integrated into a global telecommunication network. This interconnected system allows any telephone, regardless of its underlying technology or geographic location, to reach another through a unique telephone number. While mobile and landline services are fully integrated into the public switched telephone network (PSTN), some Internet-based services, such as VoIP, may not always be directly connected to the PSTN, though they still allow communication across different systems when a connection is made. This ensures that a telephone number can be used universally to connect individuals globally. (Full article...)
A mobile phone, or cell phone, is a portable telephone that allows users to make and receive calls over a radio frequency link while moving within a designated telephone service area, unlike fixed-location phones (landline phones). This radio frequency link connects to the switching systems of a mobile phone operator, providing access to the public switched telephone network (PSTN). Modern mobile telephony relies on a cellular network architecture, which is why mobile phones are often referred to as 'cell phones' in North America. Beyond traditional voice communication, digital mobile phones have evolved to support a wide range of additional services. These include text messaging, multimedia messaging, email, and internet access (via LTE, 5G NR or Wi-Fi), as well as short-range wireless technologies like Bluetooth, infrared, and ultra-wideband (UWB). Mobile phones also support a variety of multimedia capabilities, such as digital photography, video recording, and gaming. In addition, they enable multimedia playback and streaming, including video content, as well as radio and television streaming. Furthermore, mobile phones offer satellite-based services, such as navigation and messaging, as well as business applications and payment solutions (via NFC). Mobile phones offering only basic features are often referred to as feature phones (slang: "dumbphones"), while those with advanced computing power are known as smartphones. The first handheld mobile phone was demonstrated by Martin Cooper of Motorola in New York City on 3 April 1973, using a handset weighing c. 2 kilograms (4.4 lbs). In 1979, Nippon Telegraph and Telephone (NTT) launched the world's first cellular network in Japan. In 1983, the DynaTAC 8000x was the first commercially available handheld mobile phone. From 1983 to 2014, worldwide mobile phone subscriptions grew to over seven billion; enough to provide one for every person on Earth. In the first quarter of 2016, the top smartphone developers worldwide were Samsung, Apple and Huawei; smartphone sales represented 78 percent of total mobile phone sales. For feature phones as of 2016[update], the top-selling brands were Samsung, Nokia and Alcatel. Mobile phones are considered an important human invention as they have been one of the most widely used and sold pieces of consumer technology. The growth in popularity has been rapid in some places, for example, in the UK, the total number of mobile phones overtook the number of houses in 1999. Today, mobile phones are globally ubiquitous, and in almost half the world's countries, over 90% of the population owns at least one. (Full article...) A smartphone, often simply called a phone, is a mobile device that combines the functionality of a traditional mobile phone with advanced computing capabilities. It typically has a touchscreen interface, allowing users to access a wide range of applications and services, such as web browsing, email, and social media, as well as multimedia playback and streaming. Smartphones have built-in cameras, GPS navigation, and support for various communication methods, including voice calls, text messaging, and internet-based messaging apps. Smartphones are distinguished from older-design feature phones by their more advanced hardware capabilities and extensive mobile operating systems, access to the internet, business applications, mobile payments, and multimedia functionality, including music, video, gaming, radio, and television. Smartphones typically feature metal–oxide–semiconductor (MOS) integrated circuit (IC) chips, various sensors, and support for multiple wireless communication protocols. These devices leverage sensors such as accelerometers, barometers, gyroscopes, and magnetometers, which can be used by both pre-installed and third-party software to enhance functionality. In addition, smartphones are equipped to support a variety of wireless communication standards, including LTE, 5G NR, Wi-Fi, Bluetooth, and satellite navigation. By the mid-2020s, manufacturers began integrating satellite messaging and emergency services, expanding their utility in remote areas without reliable cellular coverage. Following the rising popularity of the iPhone in the late 2000s, the majority of smartphones have featured thin, slate-like form factors with large, capacitive touch screens with support for multi-touch gestures rather than physical keyboards. Most modern smartphones have the ability for users to download or purchase additional applications from a centralized app store. They often have support for cloud storage and cloud synchronization, and virtual assistants. Smartphones have largely replaced personal digital assistant (PDA) devices, handheld/palm-sized PCs, portable media players (PMP), point-and-shoot cameras, camcorders, and, to a lesser extent, handheld video game consoles, e-reader devices, pocket calculators, and GPS tracking units. Since the early 2010s, improved hardware and faster wireless communication have bolstered the growth of the smartphone industry. As of 2014, over a billion smartphones are sold globally every year. In 2019 alone, 1.54 billion smartphone units were shipped worldwide. 75.05 percent of the world population were smartphone users as of 2020. (Full article...)
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Telemarketing (sometimes known as inside sales, or telesales in the UK and Ireland) is a method of direct marketing in which a salesperson solicits prospective customers to buy products, subscriptions or services, either over the phone or through a subsequent face to face or web conferencing appointment scheduled during the call. Telemarketing can also include recorded sales pitches programmed to be played over the phone via automatic dialing. Telemarketing is defined as contacting, qualifying, and canvassing prospective customers using telecommunications devices such as telephone, fax, and internet. It does not include direct mail marketing. (Full article...)
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A foldable smartphone (also known as a foldable phone or simply foldable) is a smartphone with a folding form factor. It is reminiscent of the clamshell (or "flip phone") design of many earlier feature phones. Some variants of the concept use multiple touchscreen panels on a hinge, while other designs utilise a flexible display. Concepts of such devices date back as early as Nokia's "Morph" concept in 2008, and a concept presented by Samsung Electronics in 2013 (as part of a larger set of concepts utilizing flexible OLED displays), while the first commercially available folding smartphones with OLED displays began to emerge in November 2018. Some devices may fold out on a vertical axis to into a wider, tablet-like form, but are still usable in a smaller, folded state; the display may either wrap around to the back of the device when folded (as with the Royole FlexPai and Huawei Mate X), or use a booklet-like design where the larger, folded screen is located on the interior, and a screen on its "cover" allows the user to interact with the device without opening it (such as the Samsung Galaxy Fold series). Horizontally-folding smartphones have also been produced, typically using a clamshell form factor. The first generation of commercially released foldable smartphones faced concerns over their durability, as well as their high prices. In 2023, around 1% of worldwide smartphone ownership was foldable smartphones. (Full article...)
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2600 hertz (2600 Hz) is a frequency in hertz (cycles per second) that was used in telecommunication signaling in mid-20th century long-distance telephone networks using carrier systems.
Tone signaling carrier systems operated in the standard telephony voice frequency range (300Hz to 3500Hz). They replaced direct current (D.C.) signaling on toll trunk lines because they could be used with any type of toll facility over any length of transmission line that was suitable for voice transmissions. This included transmission through line repeaters and other facilities that would distort, block, or otherwise prohibit D.C. loop-disconnect signaling, such as rotary dial pulses, and on-hook/off-hook signaling. Common frequencies for this purpose were 1600Hz, 2000Hz, 2400Hz, 2600Hz, and 3700Hz, the latter being just outside the voice range. These signaling systems were continuous tone methods, so that the idle condition of a trunk line could easily be detected by the presence of the appropriate signaling frequency, in contrast to conditions of a quiet line which could be due to pauses in speech, or arise from line faults. The tones were typically transmitted in the same physical and logical channel, which characterizes these systems as in-band signaling methods, which do not require additional bandwidth for control of the network and benefit from a single amplification facility for speech and signaling. The most common single-frequency signaling (SF) system in use in the United States from the 1950s to the 1970s used the frequency pairing of 2600 with 2400 hertz, while in other countries, some systems combined 2600Hz with a variety of lower frequencies in a compelled mode. Lower frequencies, such as 1600Hz, were used by the 1940s in composite signaling systems, however, the higher signal energy in speech at 1600Hz presented technical problems in protection against false operation. The in-band signaling method was vulnerable to talk-off conditions when the voice of a telephone user accidentally or intentionally generates the same tone or sufficiently strong spectral content at the frequency of the signaling system, a condition also known as falsing. In this instant, the call would be disconnected prematurely, and the trunk placed in idle condition. The Bell System in the United States used special signal-to-guard arrangements in the signaling receiver to detect this condition by comparison with the energy in the frequency spectrum outside the signaling tone. The condition was also often mitigated by narrow-band notch filters during the seized line state. The discovery of this phenomenon by technology-curious individuals in the 1960s, led to the abuse by phreaking, a subculture that exploited the technology to explore national and international telephone networks and place cost-free long-distance telephone calls. Combating abuse, and improving communications, the telephone industry transitioned to out-of-band signaling systems, such as Signalling System 7 (SS7), by the 1980s. This separated the voice and signaling channels, making it impossible to generate control signals in the voice bearer channel. The development of the T-carrier system in the 1960s helped obsoleting single-frequency (SF) signaling. SF signaling was replaced by advanced methods of common channel signaling, a technology in development since the 1920s. In the 1970s, multi-frequency signaling systems came into use for international direct distance dialing (IDDD) which used the frequency of 2600Hz in line signaling in two-frequency mode with 2400Hz, for line seizure during call setup, and for tear-down. 2600Hz signaling was a standard for many international signaling systems, such as the Regional System R1. The prominent application of the 2600Hz frequency in telecommunications world-wide inspired the name of many hacker communities and publications, such as 2600: The Hacker Quarterly, and the late 20th-century counterculture 2600. (Full article...)
List articles
- Comparison of smartphones
- List of best-selling mobile phones
- List of countries by number of broadband Internet subscriptions
- List of countries by number of telephone lines in use
- List of countries by smartphone penetration
- List of country calling codes
- List of iPhone models
- List of mobile network operators
- List of mobile phone brands by country
- List of mobile phone generations
- List of telecommunications companies
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Alexander Graham Bell (/ˈɡreɪ.əm/, born Alexander Bell; March 3, 1847 – August 2, 1922) was a Scottish-born Canadian-American inventor, scientist, and engineer who is credited with patenting the first practical telephone. He also co-founded the American Telephone and Telegraph Company (AT&T) in 1885. Bell's father, grandfather, and brother had all been associated with work on elocution and speech, and both his mother and wife were deaf, profoundly influencing Bell's life's work. His research on hearing and speech further led him to experiment with hearing devices, which eventually culminated in his being awarded the first U.S. patent for the telephone, on March 7, 1876. Bell considered his invention an intrusion on his real work as a scientist and refused to have a telephone in his study. Many other inventions marked Bell's later life, including groundbreaking work in optical telecommunications, hydrofoils, and aeronautics. Bell also had a strong influence on the National Geographic Society and its magazine while serving as its second president from 1898 to 1903. Beyond his work in engineering, Bell had a deep interest in the emerging science of heredity. His work in this area has been called "the soundest, and most useful study of human heredity proposed in nineteenth-century America... Bell's most notable contribution to basic science, as distinct from invention." (Full article...)
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