By 1935, message routing was the last great barrier to full automation. Large telegraphy providers began to develop systems that used telephone-like rotary dialing to connect teletypes. These machines were called "Telex". Telex machines first performed rotary-telephone-style pulse dialing for circuit switching, and then sent data by Baudot code. This "type A" Telex routing functionally automated message routing.
The first wide-coverage Telex network was implemented in Germany during the 1930s[citation needed] as a network used to communicate within the government.
At the rate of 45.45 (±0.5%) baud — considered speedy at the time — up to 25 telex channels could share a single long-distance telephone channel by using voice frequency telegraphy multiplexing, making telex the least expensive method of reliable long-distance communication.
Canada-wide automatic teleprinter exchange service was introduced by the CPR Telegraph Company and CN Telegraph in July 1957 (the two companies, operated by rival Canadian National Railway and Canadian Pacific Railway would join to form CNCP Telecommunications in 1967). This service supplemented the existing international Telex service that was put in place in November 1956. Canadian Telex customers could connect with nineteen European countries in addition to eighteen Latin American, African, and trans-Pacific countries.[15] The major exchanges were located in Montreal (01), Toronto (02), Winnipeg (03).[16]
In 1958, Western Union Telegraph Company started to build a Telex network in the United States.[17] This Telex network started as a satellite exchange located in New York City and expanded to a nationwide network. Western Union chose Siemens & Halske AG,[18] now Siemens AG, and ITT [19] to supply the exchange equipment, provisioned the exchange trunks via the Western Union national microwave system and leased the exchange to customer site facilities from the local telephone company. Teleprinter equipment was originally provided by Siemens & Halske AG [20] and later by Teletype Corporation.[21] Initial direct International Telex service was offered by Western Union, via W.U. International, in the summer of 1960 with limited service to London and Paris.[22]
In 1962, the major exchanges were located in New York City (1), Chicago (2), San Francisco (3), Kansas City (4) and Atlanta (5).[23] The Telex network expanded by adding the final parent exchanges cities of Los Angeles (6), Dallas (7), Philadelphia (8) and Boston (9) starting in 1966.
The Telex numbering plan, usually a six-digit number in the United States, was based on the major exchange where the customer's Telex machine terminated.[24] For example, all Telex customers that terminated in the New York City exchange were assigned a Telex number that started with a first digit "1". Further, all Chicago based customers had Telex numbers that started with a first digit of "2". This numbering plan was maintained by Western Union as the Telex exchanges proliferated to smaller cities in the United States. The Western Union Telex network was built on three levels of exchanges.[25] The highest level was made up of the nine exchange cities previously mentioned. Each of these cities had the dual capability of terminating both Telex customer lines and setting up trunk connections to multiple distant Telex exchanges. The second level of exchanges, located in large cities such as Buffalo, Cleveland, Miami, Newark, Pittsburgh and Seattle, were similar to the highest level of exchanges in capability of terminating Telex customer lines and setting up trunk connections. However, these second level exchanges had a smaller customer line capacity and only had trunk circuits to regional cities. The third level of exchanges, located in small to medium sized cities, could terminate Telex customer lines and had a single trunk group running to its parent exchange.
Loop signaling was offered in two different configurations for Western Union Telex in the United States. The first option, sometimes called local or loop service, provided a 60 milliampere loop circuit from the exchange to the customer teleprinter. The second option, sometimes called long distance or polar was used when a 60 milliampere connection could not be achieved, provided a ground return polar circuit using 35 milliamperes on separate send and receive wires. By the 1970s, and under pressure from the Bell operating companies wanting to modernize their cable plant and lower the adjacent circuit noise that these Telex circuits sometimes caused, Western Union migrated customers to a third option called F1F2. This F1F2 option replaced the DC voltage of the local and long distance options with modems at the exchange and subscriber ends of the Telex circuit.
Western Union offered connections from Telex to the AT&T Teletypewriter eXchange (TWX) system in May 1966 via its New York Information Services Computer Center.[26] These connections were limited to those TWX machines that were equipped with automatic answerback capability per CCITT standard.
In 1970, Cuba and Pakistan were still running 45.5 baud type A Telex.[citation needed] Telex is still widely used in some developing countries' bureaucracies, probably because of its reliability and low cost. The UN asserted at one time that more political entities were reliably available by Telex than by any other single method.
Around 1960[?], some nations began to use the "figures" Baudot codes to perform "Type B" Telex routing.[citation needed]
Telex grew around the world very rapidly. Long before automatic telephony was available, most countries, even in central Africa and Asia, had at least a few high-frequency (shortwave) Telex links. Often these radio links were first established by government postal and telegraph services (PTTs). The most common radio standard, CCITT R.44 had error-corrected retransmitting time-division multiplexing of radio channels. Most impoverished PTTs operated their Telex-on-radio (TOR) channels non-stop, to get the maximum value from them.
The cost of TOR equipment has continued to fall. Although initially specialised equipment was required, many amateur radio operators now operate TOR (also known as RTTY) with special software and inexpensive hardware to adapt computer sound cards to short-wave radios.[citation needed]
Modern "cablegrams" or "telegrams" actually operate over dedicated Telex networks, using TOR whenever required.[citation needed]
Operation and applications
Telex messages are routed by addressing them to a Telex address, e.g. "14910 ERIC S", where 14910 is the subscriber number, ERIC is an abbreviation for the subscriber's name (in this case Telefonaktiebolaget L.M. Ericsson in Sweden) and S is the country code. Solutions also exist for the automatic routing of messages to different Telex terminals within a subscriber organization, by using different terminal identities, e.g. "+T148".
A major advantage of Telex is that the receipt of the message by the recipient could be confirmed with a high degree of certainty by the "answerback". At the beginning of the message, the sender would transmit a WRU (Who aRe yoU) code, and the recipient machine would automatically initiate a response which was usually encoded in a rotating drum with pegs, much like a music box. The position of the pegs sent an unambiguous identifying code to the sender, so the sender could verify connection to the correct recipient. The WRU code would also be sent at the end of the message, so a correct response would confirm that the connection had remained unbroken during the message transmission. This gave Telex a major advantage over less verifiable forms of communications such as telephone and fax.
The usual method of operation was that the message would be prepared off-line, using paper tape. All common Telex machines incorporated a 5-hole paper-tape punch and reader. Once the paper tape had been prepared, the message could be transmitted in minimum time. Telex billing was always by connected duration, so minimizing the connected time saved money. However, it was also possible to connect in "real time", where the sender and the recipient could both type on the keyboard and these characters would be immediately printed on the distant machine.
Telex could also be used as a rudimentary but functional carrier of information from one IT system to another, in effect a primitive forerunner of Electronic Data Interchange. The sending IT system would create an output (e.g., an inventory list) on paper tape using a mutually agreed format. The tape would be sent by Telex and collected on a corresponding paper tape by the receiver and this tape could then be read into the receiving IT system.
One use of Telex circuits, in use until the widescale adoption of x.400 and Internet email, was to facilitate a message handling system, allowing local email systems to exchange messages with other email and Telex systems via a central routing operation, or switch. One of the largest such switches was operated by Royal Dutch Shell as recently as 1994, permitting the exchange of messages between a number of IBM Officevision, Digital Equipment Corporation All-In-One and Microsoft Mail systems. In addition to permitting email to be sent to Telex addresses, formal coding conventions adopted in the composition of Telex messages enabled automatic routing of Telexes to email recipients.
Teletypewriter eXchange
The Teletypewriter eXchange (TWX) was developed by the Bell System in the United States and originally ran at 45.45 baud or 60 words per minute, using five level Baudot code. Bell later developed a second generation of TWX called "four row" that ran at 110 baud, using eight level ASCII code. The Bell System offered both "3-row" Baudot and "4-row" ASCII TWX service up to the late 1970s.
TWX used the public switched telephone network. In addition to having separate Area Codes (510, 610, 710 and 810) for the TWX service, the TWX lines were also set up with a special Class of Service to prevent connections to and from POTS to TWX and vice versa.
The code/speed conversion between "3-row" Baudot and "4-row" ASCII TWX service was accomplished using a special Bell "10A/B board" via a live operator. A TWX customer would place a call to the 10A/B board operator for Baudot - ASCII calls, ASCII - Baudot calls and also TWX Conference calls. The code / speed conversion was done by a Western Electric unit that provided this capability. There were multiple code / speed conversion units at each operator position.
Western Union purchased the TWX system from AT&T in January 1969.[27] The TWX system and the special area codes (510, 610, 710 and 810) continued right up to 1981 when Western Union completed the conversion to the Western Union Telex II system. Any remaining "3-row" Baudot customers were converted to Western Union Telex service during the period 1979 to 1981.
The modem for this service was the Bell 101 dataset, which is the direct ancestor of the Bell 103 modem that launched computer time-sharing. The 101 was revolutionary, because it ran on ordinary telephone subscriber lines, allowing the Bell System to run TWX along with POTS on a single public switched telephone network.
International Record Carriers
Bell's original consent agreement limited it to international dial telephony. The Western Union Telegraph Company had given up its international telegraphic operation in a 1939 bid to monopolize U.S. telegraphy by taking over ITT's PTT business. The result was a de-emphasis on Telex in the U.S. and a "cat's cradle" of international Telex and telegraphy companies. The Federal Communications Commission refered to these companies as "International Record Carriers" (IRCs).
- Western Union Telegraph Company developed a subsidiary named Western Union Cable System. This company later was renamed as Western Union International (WUI) when it was spun-off by Western Union as an independent company. WUI was purchased by MCI Communications (MCI) in 1983 and operated as a subsidiary of MCI International.
- ITT's "World Communications" division (later known as ITT World Communications) was amalgamated from many smaller companies: "Federal Telegraph", "All American Cables and Radio", "Globe Wireless", and the common carrier division of Mackay Marine. ITT World Communications was purchased by Western Union in 1987.
- RCA Communications (later known as RCA Global Communications) had specialized in global radiotelegraphic connections. In 1986 it was purchased by MCI International.
- Before World War I, the Tropical Radiotelegraph Company (later known as Tropical Radio Telecommunications, or TRT) put radio telegraphs on ships for its owner, the United Fruit Company (UFC), to enable them to deliver bananas to the best-paying markets. Communications expanded to UFC's plantations, and were eventually provided to local governments. TRT eventually became the national carrier for many small Central American nations.
- The French Telegraph Cable Company (later known as FTC Communications, or just FTCC), which was owned by French investors, had always been in the U.S. It laid undersea cable from the U.S. to France. It was formed by Monsieur Puyer-Quartier. International telegrams routed via FTCC were routed using the telegraphic routing ID "PQ", which are the initials of the founder of the company.
- Firestone Rubber developed its own IRC, the "Trans-Liberia Radiotelegraph Company".[citation needed] It operated shortwave from Akron, Ohio to the rubber plantations in Liberia. TL is still based in Akron.
Bell Telex users had to select which IRC to use, and then append the necessary routing digits. The IRCs converted between TWX and Western Union Telegraph Co. standards.
Arrival of the Internet
- Main article: History of the Internet. See also: E-mail and ARPANET
Around 1965, DARPA commissioned a study of decentralized switching systems. Some of the ideas developed in this study provided inspiration for the development of the ARPANET packet switching research network, which later grew to become the public Internet.
As the PSTN became a digital network, T-carrier "synchronous" networks became commonplace in the U.S. A T1 line has a "frame" of 193 bits that repeats 8000 times per second. The first bit, called the "sync" bit, alternates between 1 and 0 to identify the start of the frames. The rest of the frame provides 8 bits for each of 24 separate voice or data channels. Customarily, a T-1 link is sent over a balanced twisted pair, isolated with transformers to prevent current flow. Europeans adopted a similar system (E-1) of 32 channels (with one channel for frame synchronisation).
Later, SONET and SDH were adapted to combine carrier channels into groups that could be sent over optic fiber. The capacity of an optic fiber is often extended with wavelength division multiplexing, rather than rerigging new fibre. Rigging several fibres in the same structures as the first fibre is usually easy and inexpensive, and many fibre installations include unused spare "dark fibre", "dark wavelengths", and unused parts of the SONET frame, so-called "virtual channels."
In 2002, the Internet was used by Kevin Warwick at the University of Reading to communicate neural signals, in purely electronic form, telegraphically between the nervous systems of two humans[28], potentially opening up a new form of communication combining the Internet and telegraphy.
As of 2006[update], the fastest well-defined communication channel used for telegraphy is the SONET standard OC-768, which sends about 40 gigabits per second.[dated info]
The theoretical maximum capacity of an optic fiber is more than 1012 bits (one terabit or one trillion bits) per second[citation needed]. In 2006, no existing encoding system approached this theoretical limit, even with wavelength division multiplexing.
Since the Internet operates over any digital transmission medium, further evolution of telegraphic technology will be effectively concealed from users.
As of 2007, the Internet carried the majority of telegraphic messages in the form of e-mail[citation needed].
E-mail displaces telegraphy
E-mail was first invented for Multics in the late 1960s.[citation needed] At first, e-mail was possible only between different accounts on the same computer (typically a mainframe). UUCP allowed different computers to be connected to allow e-mails to be relayed from computer to computer. With the growth of the Internet, e-mail began to be possible between any two computers with access to the Internet.
Various private networks like UUNET (founded 1987), the Well (1985), and GEnie (1985) had e-mail from the 1970s, but subscriptions were quite expensive for an individual, US$25 to US$50 per month, just for e-mail. Internet use was then largely limited to government, academia and other government contractors until the net was opened to commercial use in the 1980s.
By the early 1990s, modems made e-mail a viable alternative to Telex systems in a business environment. But individual e-mail accounts were not widely available until local Internet service providers were in place, although demand grew rapidly, as e-mail was seen as the Internet's killer app. The broad user base created by the demand for e-mail smoothed the way for the rapid acceptance of the World Wide Web in the mid-1990s.
On Monday, 12 July 1999, a final telegram was sent from the National Liberty Ship Memorial, the SS Jeremiah O'Brien, in San Francisco Bay to President Bill Clinton in the White House. Officials of Globe Wireless reported that "The message was 95 words, and it took six or eight minutes to copy it." They then transmitted the message to the White House via e-mail. That event was also used to mark the final commercial U.S. ship-to-shore telegraph message transmitted from North America by Globe Wireless, a company founded in 1911. Sent from its wireless station at Half Moon Bay, California, the sign-off message was a repeat of Samuel F. B. Morse's message 155 years earlier, "What hath God wrought?"[29]
Worldwide status of telegram services
Eircom, Ireland's largest telecommunication company and former PTT, formally discontinued Telex services on 30 July 2002.[30] Western Union announced the discontinuation of all of its telegram services effective from 31 January 2006.[31] Only 20,000 telegrams were sent in 2005, compared with 20 million in 1929. According to Western Union, which still offers money transfer services, its last telegram was sent Friday, 27 January 2006.[32] The company stated that this was its "final transition from a communications company to a financial services company."[33] Telegram service in the United States and Canada is still available, operated by iTelegram and Globegram. Some companies, like Swedish TeliaSonera, still deliver telegrams as nostalgic novelty items, rather than a primary means of communication.
In the Netherlands, the telegram service was sold by KPN to Unitel Telegram Services in 2001 [2]. On 9 February 2007, according to the online edition of the Telegraaf newspaper, the Netherlands national telecommunications company KPN pulled the plug on the last Telex machine in the Netherlands after having operated a Telex network since 1933. As their Telex service had only 200 remaining customers, it was decided that it was no longer worthwhile to continue to offer Telex within the Netherlands. It is, however, still possible to send Telex messages to foreign customers through the Internet. In Belgium, traditional telex operations ceased 28 February 2007. The Belgacom Telex services were replaced by RealTelex, an internet based Telex alternative.[34]
In Japan, NTT provides a telegram (denpou) service that is today used mainly for special occasions such as weddings, funerals, graduations, etc.[35] Local offices offer telegrams printed on special decorated paper and envelopes.
In New Zealand, while general public use telegrams have been discontinued,[36] a modern variant has arisen for businesses, mainly utilities and the like, to send urgent confidential messages to their customers, leveraging off the perception that these are important messages. New Zealand Post describes the service as "a cost effective debt collection tool designed to help you to recover overdue money from your customers. New Zealand Post Telegrams are delivered by a courier in a Telegram branded envelope on Telegram branded paper. This has proven to be an effective method to spur customers into immediate action".[37]
In the United Kingdom, the international telegram service formerly provided by British Telecom has been spun off as an independent company which promotes the use of telegrams as a retro greeting card or invitation.[38]
In Australia, Australia Post's TELeGRAM service "combines new age demands with old world charm to offer you a quick, convenient way to send a message that matters."[39] Messages can be submitted online or by telephone, and can be printed on a range of template designs. The printed telegrams are dispatched using Express Post Mail Service or the Ordinary Mail Service. Orders received before 15:00 are dispatched on the same day. The cost of the service, being AUD4.50 for Ordinary and AUD8.50 for Express Post Mail Services in comparison with AUD0.55 for an Australia-wide postage fee, makes this service too expensive for day-to-day communication.
In Mexico, the telegram is still used as a low-cost communication service for people who cannot afford or do not have the computer skills required to send an e-mail.[40]
In Nepal, the Telex service has been discontinued as of January 1, 2009. Nepal Telecom states the reason for its decision due to "availability of advanced technology in data communication."[41]
In Bahrain, Batelco still offers telegram services. They are thought to be more formal than an email or a fax, but less so than a letter. So should a death or anything of importance occur, telegrams would be sent.
In Switzerland, UTS took over telegram services from the national PTTs. Telegrams could still be sent to and from most countries, also to those which are mentioned in this article.
Social implications
| | This article may be confusing or unclear to readers. Please help clarify the article; suggestions may be found on the talk page. (February 2009) |
Prior to the electrical telegraph, all but very small amounts of information could be moved only a few miles per hour, as fast as a human or animal could travel. The telegraph freed communication from the constraints of geography.[42] It isolated the message (information) from the physical movement of objects or the process.[43]
Telegraphy allowed organizations to actively control physical processes at a distance (for example: railroad signaling and switching of rolling stock), multiplying the effectiveness and functions of communication. "... Once space was, in the phrase of the day, annihilated, once everyone was in the same place for the purposes of trade, time as a new region of experience, uncertainty, speculation, and exploration was opened up to the forces of commerce."[44]
Worldwide telegraphy changed the gathering of information for news reporting. Since the same messages and information would now travel far and wide, the telegraph demanded a language "stripped of the local, the regional; and colloquial".[45] Media language had to be standardized, which led to the gradual disappearance of different forms of speech and styles of journalism and storytelling. It is believed that objective journalism finds its roots in the communicative strictures of the telegraph.[46]
Names of periodicals
The word "Telegraph" still appears in the names of numerous periodicals in various countries, a remnant of the long period when Telegraphy was a major means for newspapers to obtain news information (see Telegraph (disambiguation)).
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