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113-526: Early modems were devices that used audible sounds suitable for transmission over traditional telephone systems and leased lines . These generally operated at 110 or 300 bits per second (bit/s), and the connection between devices was normally manual, using an attached telephone handset . By the 1970s, higher speeds of 1,200 and 2,400 bit/s for asynchronous dial connections, 4,800 bit/s for synchronous leased line connections and 35 kbit/s for synchronous conditioned leased lines were available. By

226-464: A baseband signal which is bound to the lowest end of the spectrum, see line coding ), it is still occupying a single channel. The key difference is that what is typically considered a broadband signal in this sense is a signal that occupies multiple (non-masking, orthogonal ) passbands, thus allowing for much higher throughput over a single medium but with additional complexity in the transmitter/receiver circuitry. The term became popularized through

339-537: 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

452-446: A digital modem  – one that connects directly to a digital telephone network interface, such as T1 or PRI – could send a signal that utilized every bit of bandwidth available in the system. While that signal still had to be converted back to analog at the subscriber end, that conversion would not distort the signal in the same way that the opposite direction did. The first 56k (56 kbit/s) dial-up option

565-514: 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

678-408: A speaking tube . In the U.S., a somewhat dated slang term refers to the telephone as "the horn," as in "I couldn't get him on the horn," or "I'll be off the horn in a moment." Early telephones were technically diverse. Some used a water microphone , some had a metal diaphragm that induced current in an electromagnet wound around a permanent magnet, and some were dynamic – their diaphragm vibrated

791-499: A broadband network can be classified according to three characteristics: Cellular networks utilize various standards for data transmission, including 5G which can support one million separate devices per square kilometer. The types of traffic found in a broadband network (with examples) and their respective requirements are summarised in Table 1. Many computer networks use a simple line code to transmit one type of signal using

904-497: A coil of wire in the field of a permanent magnet or the coil vibrated the diaphragm. The sound-powered dynamic variants survived in small numbers through the 20th century in military and maritime applications, where its ability to create its own electrical power was crucial. Most, however, used the Edison/Berliner carbon transmitter , which was much louder than the other kinds, even though it required an induction coil which

1017-422: A common battery exchange had a magneto hand-cranked generator to produce a high voltage alternating signal to ring the bells of other telephones on the line and to alert the operator. Some local farming communities that were not connected to the main networks set up barbed wire telephone lines that exploited the existing system of field fences to transmit the signal. In the 1890s a new smaller style of telephone

1130-449: A diversity of services (multi-services). The Broadband Integrated Services Digital Network (B-ISDN) was planned to provide these characteristics. Asynchronous Transfer Mode (ATM) was promoted as a target technology for meeting these requirements. Different criteria for "broad" have been applied in different contexts and at different times. Its origin is in physics, acoustics , and radio systems engineering, where it had been used with

1243-485: 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. Hand-held mobile phones were introduced for personal service starting in 1973. In later decades,

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1356-486: A home and a shop. Users who wanted the ability to speak to several different locations would need to obtain and set up three or four pairs of telephones. Western Union , already using telegraph exchanges, quickly extended the principle to its telephones in New York City and San Francisco , and Bell was not slow in appreciating the potential. Signalling began in an appropriately primitive manner. The user alerted

1469-413: A meaning similar to " wideband ", or in the context of audio noise reduction systems , where it indicated a single-band rather than a multiple-audio-band system design of the compander . Later, with the advent of digital telecommunications , the term was mainly used for transmission over multiple channels . Whereas a passband signal is also modulated so that it occupies higher frequencies (compared to

1582-518: A medium with less than ideal characteristics, such as a telephone line that is of poor quality or is too long. This capability is often adaptive so that a modem can discover the maximum practical transmission rate during the connect phase, or during operation. Modems grew out of the need to connect teleprinters over ordinary phone lines instead of the more expensive leased lines which had previously been used for current loop –based teleprinters and automated telegraphs . The earliest devices which satisfy

1695-441: A medium's full bandwidth using its baseband (from zero through the highest frequency needed). Most versions of the popular Ethernet family are given names, such as the original 1980s 10BASE5 , to indicate this. Networks that use cable modems on standard cable television infrastructure are called broadband to indicate the wide range of frequencies that can include multiple data users as well as traditional television channels on

1808-586: A new industry comprising many VoIP companies that offer services to consumers and businesses . The reported global VoIP market in October 2021 was $ 85.2 billion with a projection of $ 102.5 billion by 2026. IP telephony uses high-bandwidth Internet connections and specialized customer premises equipment to transmit telephone calls via the Internet, or any modern private data network. The customer equipment may be an analog telephone adapter (ATA) which translates

1921-400: A numeric keypad for dialing, and a display for caller ID . In addition, answering machine function may be built in. The cordless handset contains a rechargeable battery , which the base station recharges when the handset rests in its cradle. Muilt-handset systems generally also have additional charging stands. A cordless telephone typically requires a constant electricity supply to power

2034-591: A satellite phone is that it can be used in such regions where local terrestrial communication infrastructures, such as landline and cellular networks, are not available. Satellite phones are popular on expeditions into remote locations, hunting, fishing, maritime sector, humanitarian missions, business trips, and mining in hard-to-reach areas, where there is no reliable cellular service. Satellite telephones rarely get disrupted by natural disasters on Earth or human actions such as war, so they have proven to be dependable communication tools in emergency situations, when

2147-431: A separate enclosure, called the subscriber set. The dial switch in the base interrupted the line current by repeatedly but very briefly disconnecting the line one to ten times for each digit, and the hook switch (in the center of the circuit diagram) disconnected the line and the transmitter battery while the handset was on the cradle. In the 1930s, telephone sets were developed that combined the bell and induction coil with

2260-601: A series of popular modems for the S-100 bus and Apple II computers that could directly dial out, answer incoming calls, and hang up entirely from software, the basic requirements of a bulletin board system (BBS). The seminal CBBS for instance was created on an S-100 machine with a Hayes internal modem, and a number of similar systems followed. Echo cancellation became a feature of modems in this period, which allowed both modems to ignore their own reflected signals. This way both modems can simultaneously transmit and receive over

2373-472: A synonym for wideband . "Broadband" in analog video distribution is traditionally used to refer to systems such as cable television , where the individual channels are modulated on carriers at fixed frequencies. In this context, baseband is the term's antonym , referring to a single channel of analog video, typically in composite form with separate baseband audio . The act of demodulating converts broadband video to baseband video. Fiber optic allows

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2486-475: A wide band of frequencies. "Broadband" is a relative term, understood according to its context. The wider (or broader) the bandwidth of a channel, the greater the data-carrying capacity, given the same channel quality. In radio , for example, a very narrow band will carry Morse code , a broader band will carry speech, and a still broader band will carry music without losing the high audio frequencies required for realistic sound reproduction . This broad band

2599-420: A wide range of complexity and quality of audio reproduction. Similarly, full motion video signals may be encoded with bit-rates ranging from less than 1 Mbit/s to hundreds of Mbit/s. Thus a network transporting both video and audio signals may have to integrate traffic with a very broad range of bit-rates. Traditionally, different telecommunications services were carried via separate networks: voice on

2712-475: A wide-spread frequency' and for services that were analog at the lowest level, nowadays in the context of Internet access , 'broadband' is often used to mean any high-speed Internet access that is seemingly always 'on' and is faster than dial-up access over traditional analog or ISDN PSTN services. The ideal telecommunication network has the following characteristics: broadband , multi-media , multi-point , multi-rate and economical implementation for

2825-514: A wired interface, such as USB or Lightning connectors. Smartphones, being able to run apps , have vastly expanded functionality compared to previous mobile phones. Having internet access and built in cameras, smartphones have made video calling readily accessible via IP connections. Smartphones also have access to a large number of web services and web apps, giving them functionality similar to traditional computers, although smartphones are often limited by their relatively small screen size and

2938-462: Is converted to a non-loaded twisted-pair wire (no telephone filters), it becomes hundreds of kilohertz wide (broadband) and can carry up to 100 megabits per second using very high-bit rate digital subscriber line ( VDSL or VHDSL) techniques. Modern networks have to carry integrated traffic consisting of voice, video and data. The Broadband Integrated Services Digital Network (B-ISDN) was designed for these needs. The types of traffic supported by

3051-489: Is derived from the Greek : τῆλε , tēle , "far" and φωνή, phōnē , "voice", together meaning "distant voice". Credit for the invention of the electric telephone is frequently disputed. As with other influential inventions such as radio , television , the light bulb , and the computer , several inventors pioneered experimental work on voice transmission over a wire and improved on each other's ideas. New controversies over

3164-428: Is limited, usually to within the same building or within a short distance from the base station. Base stations include a radio transceiver which enables full-duplex, outgoing and incoming signals and speech with the handsets. The base station often includes a microphone, audio amplifier , and a loudspeaker to enable hands-free speakerphone conversations, without needing to use a handset. The base station may also have

3277-437: Is near the theoretical Shannon limit of a phone line. While 56 kbit/s speeds had been available for leased-line modems for some time, they did not become available for dial up modems until the late 1990s. In the late 1990s, technologies to achieve speeds above 33.6 kbit/s began to be introduced. Several approaches were used, but all of them began as solutions to a single fundamental problem with phone lines. By

3390-525: Is often divided into channels or "frequency bins" using passband techniques to allow frequency-division multiplexing instead of sending a higher-quality signal. In data communications, a 56k modem will transmit a data rate of 56 kilobits per second (kbit/s) over a 4-kilohertz-wide telephone line (narrowband or voiceband ). In the late 1980s, the Broadband Integrated Services Digital Network (B-ISDN) used

3503-480: Is the ITU-T G.hn standard, which provides a way to create a local area network up to 1 Gigabit/s (which is considered high-speed as of 2014) using existing home business and home wiring (including power lines, but also phone lines and coaxial cables ). In 2014, researchers at Korea Advanced Institute of Science and Technology made developments on the creation of ultra-shallow broadband optical instruments . In

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3616-663: The Earth instead of terrestrial cell sites , as cellphones do. Therefore, they can work in most geographic locations on the Earth's surface, as long as open sky and the line-of-sight between the phone and the satellite is provided. Depending on the architecture of a particular system, coverage may include the entire Earth or only specific regions. Satellite phones provide similar functionality to terrestrial mobile telephones; voice calling , text messaging , and low-bandwidth Internet access are supported through most systems. The advantage of

3729-612: The Internet , giving rise to the field of Internet Protocol (IP) telephony, also known as voice over Internet Protocol (VoIP). VoIP has proven to be a disruptive technology that is rapidly replacing traditional telephone network infrastructure. By January 2005, up to 10% of telephone subscribers in Japan and South Korea had switched to this digital telephone service. A January 2005 Newsweek article suggested that Internet telephony may be "the next big thing." The technology has spawned

3842-695: The VA3400 which performed full-duplex at 1,200 bit/s over a normal phone line. In November 1976, AT&T introduced the 212A modem, similar in design, but using the lower frequency set for transmission. It was not compatible with the VA3400, but it would operate with 103A modem at 300 bit/s. In 1977, Vadic responded with the VA3467 triple modem, an answer-only modem sold to computer center operators that supported Vadic's 1,200-bit/s mode, AT&T's 212A mode, and 103A operation. A significant advance in modems

3955-754: The 1970s, independently made modems compatible with the Bell 103 de facto standard were commonplace. Example models included the Novation CAT and the Anderson-Jacobson . A lower-cost option was the Pennywhistle modem , designed to be built using readily available parts. Teletype machines were granted access to remote networks such as the Teletypewriter Exchange using the Bell 103 modem. AT&T also produced reduced-cost units,

4068-419: The 1980s, less expensive 1,200 and 2,400 bit/s dialup modems were being released, and modems working on radio and other systems were available. As device sophistication grew rapidly in the late 1990s, telephone-based modems quickly exhausted the available bandwidth , reaching 56 kbit/s. The rise of public use of the internet during the late 1990s led to demands for much higher performance, leading to

4181-594: The 1990s as a marketing term for Internet access that was faster than dial-up access (dial-up being typically limited to a maximum of 56 kbit/s). This meaning is only distantly related to its original technical meaning. Since 1999, broadband Internet access has been a factor in public policy . In that year, at the World Trade Organization Biannual Conference called “ Financial Solutions to Digital Divide ” in Seattle,

4294-658: The 1990s, mobile phones have gained other features which are not directly related to their primary function as telephones. These include text messaging, calendars, alarm clocks, personal schedulers, cameras, music players, games and later, internet access and smartphone functionality. Nearly all mobile phones have the ability to send text messages to other users via the SMS (Short Message Service) protocol. The multimedia messaging service (MMS) protocol enables users to send and receive multimedia content, such as photos, audio files and video files. As their functionality has increased over

4407-695: The FCC in December 2017. A number of national and international regulators categorize broadband connections according to upload and download speeds, stated in Mbit/s ( megabits per second ). In Australia, the Australian Competition and Consumer Commission also requires Internet Service Providers to quote speed during night time and busy hours Bandwidth has historically been very unequally distributed worldwide with increasing concentration in

4520-575: The SAGE director centers scattered around the United States and Canada . Shortly afterwards in 1959, the technology in the SAGE modems was made available commercially as the Bell 101 , which provided 110 bit/s speeds. Bell called this and several other early modems "datasets". Some early modems were based on touch-tone frequencies, such as Bell 400-style touch-tone modems. The Bell 103A standard

4633-519: The Smartmodem made communications much simpler and more easily accessed. This provided a growing market for other vendors, who licensed the Hayes patents and competed on price or by adding features. This eventually led to legal action over use of the patented Hayes command language. Dial modems generally remained at 300 and 1,200 bit/s (eventually becoming standards such as V.21 and V.22 ) into

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4746-493: The advent of smartphones, mobile phone manufacturers have also included consumer electronics companies, such as Apple , Samsung and Xiaomi . As of 2022, most mobile phones are smartphones, being a combination of a mobile phone and a personal computing device in the same unit. Most smartphones are primarily operated using a graphical user interface and a touch screen. Many phones have a secondary voice user interface, such as Siri on Apple iPhones , which can operate many of

4859-451: 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. Before the development of the electric telephone, the term telephone was applied to other inventions, and not all early researchers of

4972-401: The assistance of a telephone operator. What turned out to be the most popular and longest-lasting physical style of telephone was introduced in the early 20th century, including Bell's 202-type desk set. A carbon granule transmitter and electromagnetic receiver were united in a single molded plastic handle, which when not in use was secured in a cradle in the base unit. The circuit diagram of

5085-526: The base station and charger units by means of a DC transformer which plugs into a wall AC power outlet. A mobile phone or cellphone or hand phone is a handheld telephone which connects via radio transmissions to a cellular telephone network . The cellular network consists of a network of ground based transmitter/receiver stations with antennas – which are usually located on towers or on buildings – and infrastructure connecting to land-based telephone lines. Analog cellular networks first appeared in 1979, with

5198-404: The bell, induction coil, battery and magneto were in a separate bell box or " ringer box ". In phones connected to common battery exchanges, the ringer box was installed under a desk, or other out-of-the-way place, since it did not need a battery or magneto. Cradle designs were also used at this time, having a handle with the receiver and transmitter attached, now called a handset , separate from

5311-409: The capacity, quality, and cost of the network. Integrated Services Digital Network (ISDN) was launched in the 1980's, providing businesses and consumers with access to digital telephony services such as data, voice, video , and fax services. The development of digital data communications methods made it possible to digitize voice and transmit it as real-time data across computer networks and

5424-582: The connection and media requests of a multipoint, multimedia communication call. A multirate service network is one which flexibly allocates transmission capacity to connections. A multimedia network has to support a broad range of bit-rates demanded by connections, not only because there are many communication media, but also because a communication medium may be encoded by algorithms with different bit-rates. For example, audio signals can be encoded with bit-rates ranging from less than 1 kbit/s to hundreds of kbit/s, using different encoding algorithms with

5537-408: The context of Internet access , the term "broadband" is used loosely to mean "access that is always on and faster than the traditional dial-up access". A range of more precise definitions of speed have been prescribed at times, including: Broadband Internet service in the United States was effectively treated or managed as a public utility by net neutrality rules until being overturned by

5650-470: The cradle base that housed the magneto crank and other parts. They were larger than the "candlestick" and more popular. Disadvantages of single-wire operation such as crosstalk and hum from nearby AC power wires had already led to the use of twisted pairs and, for long-distance telephones, four-wire circuits . Users at the beginning of the 20th century did not place long-distance calls from their own telephones but made an appointment and were connected with

5763-520: The definition of a modem may have been the multiplexers used by news wire services in the 1920s. In 1941, the Allies developed a voice encryption system called SIGSALY which used a vocoder to digitize speech, then encrypted the speech with one-time pad and encoded the digital data as tones using frequency shift keying. This was also a digital modulation technique, making this an early modem. Commercial modems largely did not become available until

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5876-469: The desk set, obviating a separate ringer box. The rotary dial becoming commonplace in the 1930s in many areas enabled customer-dialed service, but some magneto systems remained even into the 1960s. After World War II, the telephone networks saw rapid expansion and more efficient telephone sets, such as the model 500 telephone in the United States, were developed that permitted larger local networks centered around central offices. A breakthrough new technology

5989-420: The device's functions, as well as enabling users to use spoken commands to interact with the internet. Typically alphanumeric text input is accomplished via an on-screen virtual keyboard, although some smartphones have a small physical keyboard. Smartphones offer the ability to access internet data through the cellular network and via wi-fi, and usually allow direct connectivity to other devices via Bluetooth or

6102-518: The digital age. Historically only 10 countries have hosted 70–75% of the global telecommunication capacity (see pie-chart Figure on the right). In 2014, only three countries (China, the US, and Japan) host 50% of the globally installed telecommunication bandwidth potential. The U.S. lost its global leadership in terms of installed bandwidth in 2011, being replaced by China, which hosts more than twice as much national bandwidth potential in 2014 (29% versus 13% of

6215-417: The digitization itself placed constraints on the types of waveforms that could be reliably encoded. The first problem was that the process of analog-to-digital conversion is intrinsically lossy, but second, and more importantly, the digital signals used by the telcos were not "linear": they did not encode all frequencies the same way, instead utilizing a nonlinear encoding ( μ-law and a-law ) meant to favor

6328-523: The draft of a new 56 kbit/s standard V.90 with strong industry support. Incompatible with either existing standard, it was an amalgam of both, but was designed to allow both types of modem by a firmware upgrade. The V.90 standard was approved in September 1998 and widely adopted by ISPs and consumers. Telephone A telephone , colloquially referred to as a phone , is a telecommunications device that permits two or more users to conduct

6441-402: The earliest Strowger switch automatic exchanges had seven wires, one for the knife switch , one for each telegraph key , one for the bell, one for the push-button and two for speaking. Large wall telephones in the early 20th century usually incorporated the bell, and separate bell boxes for desk phones dwindled away in the middle of the century. Rural and other telephones that were not on

6554-779: The economy of sharing. This economy motivates the general idea of an integrated services network. Integration avoids the need for many overlaying networks, which complicates network management and reduces flexibility in the introduction and evolution of services. This integration was made possible with advances in broadband technologies and high-speed information processing of the 1990s. While multiple network structures were capable of supporting broadband services, an ever-increasing percentage of broadband and MSO providers opted for fibre-optic network structures to support both present and future bandwidth requirements. CATV (cable television), HDTV (high definition television), VoIP (voice over internet protocol), and broadband internet are some of

6667-457: The electrical device used the term. Perhaps the earliest use of the word for a communications system was the telephon created by Gottfried Huth in 1796. Huth proposed an alternative to the optical telegraph of Claude Chappe in which the operators in the signaling towers would shout to each other by means of what he called "speaking tubes", but would now be called giant megaphones . A communication device for sailing vessels, called telephone ,

6780-420: The fact that the 10PASS-TS standard for Ethernet ratified in 2008 used DSL technology, and both cable and DSL modems often have Ethernet connectors on them. A television antenna may be described as "broadband" because it is capable of receiving a wide range of channels, while e.g. a low-VHF antenna is "narrowband" since it receives only 1 to 5 channels. The U.S. federal standard FS-1037C defines "broadband" as

6893-524: The first digital cellular networks appearing in the early 1990s. Mobile phones require a SIM card to be inserted into the phone. The SIM card is a small PVC card containing a small integrated circuit which stores the user's international mobile subscriber identity (IMSI) number and its related key, which are used to identify and authenticate subscribers to the cellular network. Mobile phones generally incorporate an LCD or OLED display, with some types, such as smartphones, having touch screens. Since

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7006-431: The full spectrum of the phone line, improving the available bandwidth. Additional improvements were introduced by quadrature amplitude modulation (QAM) encoding, which increased the number of bits per symbol to four through a combination of phase shift and amplitude. Transmitting at 1,200 baud produced the 4,800 bit/s V.27ter standard, and at 2,400 baud the 9,600 bit/s V.32 . The carrier frequency

7119-402: The information generated by other media. For example, voice could be transcribed into data via voice recognition, and data commands may control the way voice and video are presented. These interactions most often occur at the communication terminals, but may also occur within the network. Traditional voice calls are predominantly two party calls, requiring a point-to-point connection using only

7232-549: The information into the system. However, "broadband video" in the context of streaming Internet video has come to mean video files that have bit-rates high enough to require broadband Internet access for viewing. "Broadband video" is also sometimes used to describe IPTV Video on demand . Power lines have also been used for various types of data communication. Although some systems for remote control are based on narrowband signaling, modern high-speed systems use broadband signaling to achieve very high data rates. One example

7345-531: The issue still arise from time to time. Charles Bourseul , Antonio Meucci , Johann Philipp Reis , Alexander Graham Bell , and Elisha Gray , amongst others, have all been credited with the invention of the telephone. Alexander Graham Bell was the first to be awarded a patent for the electric telephone by the United States Patent and Trademark Office (USPTO) in March 1876. Before Bell's patent,

7458-710: The late 1950s, when the rapid development of computer technology created demand for a method of connecting computers together over long distances, resulting in the Bell Company and then other businesses producing an increasing number of computer modems for use over both switched and leased telephone lines. Later developments would produce modems that operated over cable television lines , power lines , and various radio technologies , as well as modems that achieved much higher speeds over telephone lines. A dial-up modem transmits computer data over an ordinary switched telephone line that has not been designed for data use. It

7571-601: The late 1980s, many modems could support improved standards like this, and 2,400-bit/s operation was becoming common. Increasing modem speed greatly improved the responsiveness of online systems and made file transfer practical. This led to rapid growth of online services with large file libraries, which in turn gave more reason to own a modem. The rapid update of modems led to a similar rapid increase in BBS use. The introduction of microcomputer systems with internal expansion slots made small internal modems practical. This led to

7684-466: The lengthy introduction of the 28,800 bit/s V.34 standard. While waiting, several companies decided to release hardware and introduced modems they referred to as V.Fast . In order to guarantee compatibility with V.34 modems once a standard was ratified (1994), manufacturers used more flexible components, generally a DSP and microcontroller , as opposed to purpose-designed ASIC modem chips. This would allow later firmware updates to conform with

7797-479: The local communications system can be compromised. Broadband In telecommunications , broadband or high speed is the wide- bandwidth data transmission that exploits signals at a wide spread of frequencies or several different simultaneous frequencies, and is used in fast Internet access . The transmission medium can be coaxial cable , optical fiber , wireless Internet ( radio ), twisted pair cable, or satellite . Originally used to mean 'using

7910-767: The market around February 1997; although problems with K56Flex modems were noted in product reviews through July, within six months the two technologies worked equally well, with variations dependent largely on local connection characteristics. The retail price of these early 56k modems was about US$ 200 , compared to $ 100 for standard 33k modems. Compatible equipment was also required at the Internet service providers (ISPs) end, with costs varying depending on whether their current equipment could be upgraded. About half of all ISPs offered 56k support by October 1997. Consumer sales were relatively low, which USRobotics and Rockwell attributed to conflicting standards. In February 1998, The International Telecommunication Union (ITU) announced

8023-518: The market when V.32bis was standardized, which operated at 14,400 bit/s. Rockwell International 's chip division developed a new driver chip set incorporating the V.32bis standard and aggressively priced it. Supra, Inc. arranged a short-term exclusivity arrangement with Rockwell, and developed the SupraFAXModem 14400 based on it. Introduced in January 1992 at $ 399 (or less), it was half

8136-468: The mid-1980s. Commodore's 1982 VicModem for the VIC-20 was the first modem to be sold under $ 100, and the first modem to sell a million units. In 1984, V.22bis was created, a 2,400-bit/s system similar in concept to the 1,200-bit/s Bell 212. This bit rate increase was achieved by defining four or sixteen distinct symbols, which allowed the encoding of two or four bits per symbol instead of only one. By

8249-412: The model 202 shows the direct connection of the transmitter to the line, while the receiver was inductively coupled. In local battery configurations, when the local loop was too long to provide sufficient current from the exchange, the transmitter was powered by a local battery and inductively coupled, while the receiver was included in the local loop. The coupling transformer and the ringer were mounted in

8362-412: The most common applications now being supported by fibre optic networks, in some cases directly to the home (FTTh – Fibre To The Home). These types of fibre optic networks incorporate a wide variety of products to support and distribute the signal from the central office to an optic node, and ultimately to the subscriber (end-user). In telecommunications , a broadband signalling method is one that handles

8475-484: The move away from audio-based systems to entirely new encodings on cable television lines and short-range signals in subcarriers on telephone lines. The move to cellular telephones , especially in the late 1990s and the emergence of smartphones in the 2000s led to the development of ever-faster radio-based systems. Today, modems are ubiquitous and largely invisible, included in almost every mobile computing device in one form or another, and generally capable of speeds on

8588-400: The nonlinear response of the human ear to voice signals. This made it very difficult to find a 56 kbit/s encoding that could survive the digitizing process. Modem manufacturers discovered that, while the analog to digital conversion could not preserve higher speeds, digital-to-analog conversions could. Because it was possible for an ISP to obtain a direct digital connection to a telco,

8701-582: The number of times per second the modem sends a new signal. For example, the ITU-T V.21 standard used audio frequency-shift keying with two possible frequencies, corresponding to two distinct symbols (or one bit per symbol), to carry 300 bits per second using 300 baud. By contrast, the original ITU-T V.22 standard, which could transmit and receive four distinct symbols (two bits per symbol), transmitted 1,200 bits by sending 600 symbols per second (600 baud) using phase-shift keying . Many modems are variable-rate, permitting them to be used over

8814-514: The order of tens or hundreds of megabytes per second. Modems are frequently classified by the maximum amount of data they can send in a given unit of time , usually expressed in bits per second (symbol bit/s , sometimes abbreviated "bps") or rarely in bytes per second (symbol B/s ). Modern broadband modem speeds are typically expressed in megabits per second (Mbit/s). Historically, modems were often classified by their symbol rate , measured in baud . The baud unit denotes symbols per second, or

8927-427: The originate-only 113D and the answer-only 113B/C modems. The 201A Data-Phone was a synchronous modem using two-bit-per-symbol phase-shift keying (PSK) encoding, achieving 2,000 bit/s half-duplex over normal phone lines. In this system the two tones for any one side of the connection are sent at similar frequencies as in the 300 bit/s systems, but slightly out of phase. In early 1973, Vadic introduced

9040-471: The other end, or the exchange operator , by whistling into the transmitter. Exchange operation soon resulted in telephones being equipped with a bell in a ringer box , first operated over a second wire, and later over the same wire, but with a condenser ( capacitor ) in series with the bell coil to allow the AC ringer signal through while still blocking DC (keeping the phone " on hook "). Telephones connected to

9153-461: The other hand, data networks which store and forward messages using computers had limited connectivity, usually did not have sufficient bandwidth for digitised voice and video signals, and suffer from unacceptable delays for the real-time signals. Television networks using radio or cables were largely broadcast networks with minimum switching facilities. It was desirable to have a single network for providing all these communication services to achieve

9266-580: The present overcrowded radio spectrum. A modern telecommunications network (such as the broadband network) must provide all these different services ( multi-services ) to the user. Conventional telephony communication used: Modern services can be: These aspects are examined individually in the following three sub-sections. A multimedia call may communicate audio, data, still images, or full-motion video , or any combination of these media. Each medium has different demands for communication quality, such as: The information content of each medium may affect

9379-564: The price of the slower V.32 modems already on the market. This led to a price war, and by the end of the year V.32 was dead, never having been really established, and V.32bis modems were widely available for $ 250 . V.32bis was so successful that the older high-speed standards had little advantages. USRobotics (USR) fought back with a 16,800 bit/s version of HST, while AT&T introduced a one-off 19,200 bit/s method they referred to as V.32ter , but neither non-standard modem sold well. Consumer interest in these proprietary improvements waned during

9492-493: The same cable. Broadband systems usually use a different radio frequency modulated by the data signal for each band. The total bandwidth of the medium is larger than the bandwidth of any channel. The 10BROAD36 broadband variant of Ethernet was standardized by 1985, but was not commercially successful. The DOCSIS standard became available to consumers in the late 1990s, to provide Internet access to cable television residential customers. Matters were further confused by

9605-426: The service location to the emergency services when an emergency telephone number is called. A cordless telephone or portable telephone consists of a base station unit and one or more portable cordless handsets . The base station connects to a telephone line, or provides service by voice over IP (VOIP). The handset communicates with the base station via radio frequency signals. A handset's operational range

9718-413: The signal to be transmitted farther without being repeated. Cable companies use a hybrid system using fiber to transmit the signal to neighborhoods and then changes the signal from light to radio frequency to be transmitted over coaxial cable to homes. Doing so reduces the use of having multiple head ends. A head end gathers all the information from the local cable networks and movie channels and then feeds

9831-453: The signals of a conventional analog telephone; an IP Phone , a dedicated standalone device; or a computer softphone application, utilizing the microphone and headset devices of a personal computer or smartphone. While traditional analog telephones are typically powered from the central office through the telephone line, digital telephones require a local power supply. Internet-based digital service also requires special provisions to provide

9944-510: The size of their keyboards. Typically, smartphones feature such tools as cameras, media players, web browsers, email clients, interactive maps, satellite navigation and a variety of sensors, such as a compass , accelerometers and GPS receivers . In addition to voice calls, smartphone users commonly communicate using a wide variety of messaging formats, including SMS, MMS, email, and various proprietary messaging services, such as iMessage and various social media platforms. In 2002, only 10% of

10057-467: The standards once ratified. The ITU standard V.34 represents the culmination of these joint efforts. It employed the most powerful coding techniques available at the time, including channel encoding and shape encoding. From the mere four bits per symbol ( 9.6  kbit/s ), the new standards used the functional equivalent of 6 to 10 bits per symbol, plus increasing baud rates from 2,400 to 3,429, to create 14.4, 28.8, and 33.6 kbit/s modems. This rate

10170-410: The telephone network, data on computer networks such as local area networks , video teleconferencing on private corporate networks, and television on broadcast radio or cable networks. These networks were largely engineered for a specific application and are not suited to other applications. For example, the traditional telephone network is too noisy and inefficient for bursty data communication. On

10283-458: The telephone transmitted sound in a way that was similar to the telegraph. This method used vibrations and circuits to send electrical pulses, but was missing key features. Bell found that this method produced a sound through intermittent currents, but in order for the telephone to work a fluctuating current reproduced sounds the best. The fluctuating currents became the basis for the working telephone, creating Bell's patent. That first patent by Bell

10396-438: The term to refer to a broad range of bit rates , independent of physical modulation details. The various forms of digital subscriber line (DSL) services are broadband in the sense that digital information is sent over multiple channels. Each channel is at a higher frequency than the baseband voice channel, so it can support plain old telephone service on a single pair of wires at the same time. However, when that same line

10509-444: The term “Meaningful Broadband” was introduced to the world leaders, leading to the activation of a movement to close the digital divide . Fundamental aspects of this movement are to suggest that the equitable distribution of broadband is a fundamental human right. Personal computing facilitated easy access, manipulation, storage, and exchange of information, and required reliable data transmission. Communicating documents by images and

10622-423: The time technology companies began to investigate speeds above 33.6 kbit/s , telephone companies had switched almost entirely to all-digital networks. As soon as a phone line reached a local central office, a line card converted the analog signal from the subscriber to a digital one and conversely. While digitally encoded telephone lines notionally provide the same bandwidth as the analog systems they replaced,

10735-412: The use of high-resolution graphics terminals provided a more natural and informative mode of human interaction than do voice and data alone. Video teleconferencing enhances group interaction at a distance. High-definition entertainment video improves the quality of pictures, but requires much higher transmission rates. These new data transmission requirements may require new transmission means other than

10848-438: The user alternately listening and speaking (or rather, shouting) into the same hole. Sometimes the instruments were operated in pairs at each end, making conversation more convenient but also more expensive. At first, the benefits of a telephone exchange were not exploited. Instead, telephones were leased in pairs to a subscriber , who had to arrange for a telegraph contractor to construct a line between them, for example, between

10961-522: 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

11074-556: The voice medium. To access pictorial information in a remote database would require a point-to-point connection that sends low bit-rate queries to the database and high bit-rate video from the database. Entertainment video applications are largely point-to-multi-point connections, requiring one way communication of full motion video and audio from the program source to the viewers. Video teleconferencing involves connections among many parties, communicating voice, video, as well as data. Offering future services thus requires flexible management of

11187-456: The world's population used mobile phones and by 2005 that percentage had risen to 46%. By the end of 2009, there were a total of nearly 6 billion mobile and fixed-line telephone subscribers worldwide. This included 1.26 billion fixed-line subscribers and 4.6 billion mobile subscribers. A satellite telephone, or satphone, is a type of mobile phone that connects to other phones or the telephone network by radio link through satellites orbiting

11300-517: The years, many types of mobile phone, notably smartphones, require an operating system to run. Popular mobile phone operating systems in the past have included Symbian , Palm OS , BlackBerry OS and mobile phone versions of Windows . As of 2022, the most used operating systems are Google's Android and Apple's iOS . Before the era of smartphones, mobile phones were generally manufactured by companies specializing in telecommunications equipment, such as Nokia , Motorola , and Ericsson . Since

11413-499: Was 1,650 Hz in both systems. The introduction of these higher-speed systems also led to the development of the digital fax machine during the 1980s. While early fax technology also used modulated signals on a phone line, digital fax used the now-standard digital encoding used by computer modems. This eventually allowed computers to send and receive fax images. In the early 1990s, V.32 modems operating at 9,600 bit/s were introduced, but were expensive and were only starting to enter

11526-469: Was a proprietary design from USRobotics , which they called "X2" because 56k was twice the speed (×2) of 28k modems. At that time, USRobotics held a 40% share of the retail modem market, while Rockwell International held an 80% share of the modem chipset market. Concerned with being shut out, Rockwell began work on a rival 56k technology. They joined with Lucent and Motorola to develop what they called "K56Flex" or just "Flex". Both technologies reached

11639-410: Was an impedance matching transformer to make it compatible with the impedance of the line. The Edison patents kept the Bell monopoly viable into the 20th century, by which time the network was more important than the instrument. Early telephones were locally powered, using either a dynamic transmitter or by the powering of a transmitter with a local battery. One of the jobs of outside plant personnel

11752-456: Was integrated into devices from many other manufacturers. Automatic dialing was not a new capability—it had been available via separate Automatic Calling Units , and via modems using the X.21 interface—but the Smartmodem made it available in a single device that could be used with even the most minimal implementations of the ubiquitous RS-232 interface, making this capability accessible from virtually any system or language. The introduction of

11865-411: Was introduced by AT&T in 1962. It provided full-duplex service at 300 bit/s over normal phone lines. Frequency-shift keying was used, with the call originator transmitting at 1,070 or 1,270  Hz and the answering modem transmitting at 2,025 or 2,225 Hz. The 103 modem would eventually become a de facto standard once third-party (non-AT&T modems) reached the market, and throughout

11978-436: Was introduced, packaged in three parts. The transmitter stood on a stand, known as a " candlestick " for its shape. When not in use, the receiver hung on a hook with a switch in it, known as a "switchhook". Previous telephones required the user to operate a separate switch to connect either the voice or the bell. With the new kind, the user was less likely to leave the phone "off the hook". In phones connected to magneto exchanges,

12091-539: Was invented by Captain John Taylor in 1844. This instrument used four air horns to communicate with vessels in foggy weather. Johann Philipp Reis used the term in reference to his invention, commonly known as the Reis telephone , in c. 1860. His device appears to be the first device based on the conversion of sound into electrical impulses. The term telephone was adopted into the vocabulary of many languages. It

12204-546: Was once a widely known technology, mass-marketed globally dial-up internet access . In the 1990s, tens of millions of people in the United States alone used dial-up modems for internet access. Dial-up service has since been largely superseded by broadband internet , such as DSL . Mass production of telephone line modems in the United States began as part of the SAGE air-defense system in 1958, connecting terminals at various airbases, radar sites, and command-and-control centers to

12317-535: Was the Hayes Smartmodem , introduced in 1981. The Smartmodem was an otherwise standard 103A 300 bit/s direct-connect modem, but it introduced a command language which allowed the computer to make control requests, such as commands to dial or answer calls, over the same RS-232 interface used for the data connection. The command set used by this device became a de facto standard, the Hayes command set , which

12430-499: Was the master patent of the telephone, from which other patents for electric telephone devices and features flowed. In 1876, shortly after Bell's patent application, Hungarian engineer Tivadar Puskás proposed the telephone switch, which allowed for the formation of telephone exchanges , and eventually networks. In the United Kingdom, the blower is used as a slang term for a telephone. The term came from navy slang for

12543-426: 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

12656-591: Was the introduction of Touch-Tone signaling using push-button telephones by American Telephone & Telegraph Company (AT&T) in 1963. The invention of the transistor in 1947 dramatically changed the technology used in telephone systems and in the long-distance transmission networks, over the next several decades. With the development of stored program control and MOS integrated circuits for electronic switching systems , and new transmission technologies such as pulse-code modulation (PCM), telephony gradually evolved towards digital telephony , which improved

12769-423: Was to visit each telephone periodically to inspect the battery. During the 20th century, telephones powered from the telephone exchange over the same wires that carried the voice signals became common. Early telephones used a single wire for the subscriber's line, with ground return used to complete the circuit (as used in telegraphs ). The earliest dynamic telephones also had only one port opening for sound, with

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