Telephony is the field of technology involving the development and deployment of telecommunication services for the purpose of electronic transmission of voice, fax, or data, between distant parties. The history of telephony is intimately linked to the development of the telephone. Telephony is referred to as the construction or operation of telephones and telephonic systems and as a system of telecommunications in which telephonic equipment is employed in the transmission of speech or other sound between points, with or without the use of wires; the term is used to refer to computer hardware and computer network systems, that perform functions traditionally performed by telephone equipment. In this context the technology is referred to as Internet telephony, or voice over Internet Protocol; the first telephones were connected directly in pairs. Each user had a separate telephone wired to each locations to be reached; this became inconvenient and unmanageable when users wanted to communicate with more than a few people.

The invention of the telephone exchange provided the solution for establishing telephone connections with any other telephone in service in the local area. Each telephone was connected to the exchange at first with one wire one wire pair, the local loop. Nearby exchanges in other service areas were connected with trunk lines and long distance service could be established by relaying the calls through multiple exchanges. Exchange switchboards were manually operated by an attendant referred to as the "switchboard operator"; when a customer cranked a handle on the telephone, it activated an indicator on the board in front of the operator, who would in response plug the operator headset into that jack and offer service. The caller had to ask for the called party by name by number, the operator connected one end of a circuit into the called party jack to alert them. If the called station answered, the operator disconnected their headset and completed the station-to-station circuit. Trunk calls were made with the assistance of other operators at other exchangers in the network.

Until the 1970s, most telephones were permanently wired to the telephone line installed at customer premises. Conversion to installation of jacks that terminated the inside wiring permitted simple exchange of telephone sets with telephone plugs and allowed portability of the set to multiple locations in the premises where jacks were installed; the inside wiring to all jacks was connected in one place to the wire drop which connects the building to a cable. Cables bring a large number of drop wires from all over a district access network to one wire center or telephone exchange; when a telephone user wants to make a telephone call, equipment at the exchange examines the dialed telephone number and connects that telephone line to another in the same wire center, or to a trunk to a distant exchange. Most of the exchanges in the world are interconnected through a system of larger switching systems, forming the public switched telephone network. In the second half of the 20th century and data became important secondary applications of the network created to carry voices, late in the century, parts of the network were upgraded with ISDN and DSL to improve handling of such traffic.

Today, telephony uses digital technology in the provisioning of telephone systems. Telephone calls can be provided digitally, but may be restricted to cases in which the last mile is digital, or where the conversion between digital and analog signals takes place inside the telephone; this advancement has reduced costs in communication, improved the quality of voice services. The first implementation of this, ISDN, permitted all data transport from end-to-end speedily over telephone lines; this service was made much less important due to the ability to provide digital services based on the IP protocol. Since the advent of personal computer technology in the 1980s, computer telephony integration has progressively provided more sophisticated telephony services and controlled by the computer, such as making and receiving voice and data calls with telephone directory services and caller identification; the integration of telephony software and computer systems is a major development in the evolution of office automation.

The term is used in describing the computerized services of call centers, such as those that direct your phone call to the right department at a business you're calling. It's sometimes used for the ability to use your personal computer to initiate and manage phone calls. CTI is not a new concept and has been used in the past in large telephone networks, but only dedicated call centers could justify the costs of the required equipment installation. Primary telephone service providers are offering information services such as automatic number identification, a telephone service architecture that separates CTI services from call switching and will make it easier to add new services. Dialed Number Identification Service on a scale is wide enough for its implementation to bring real value to business or residential telephone usage. A new generation of applications is being developed as a result of standardization and availability of low cost computer telephony links. Digital telephony is the use of digital electronics in the operation and provisioning of telephony systems and services.

Since the late 20th century, a digital core network has replaced the traditional analog transmission and signaling systems, much of the access network has been digitized. Starting wit

The Honda XLV750R is a dual-sport motorcycle manufactured from 1983 to 1986 by Honda Motor Company, Japan. A first prototype of the motorcycle was introduced to the public at the Paris Motor Show in October 1982; the XLV was intended for the European market only, but from 1985 on, it was sold in Australia and New Zealand. In the first production run in 1983, 500 "Limited Edition"-models were produced for the Japanese home market; the "Limited Edition"-models can be identified by a golden metal badge attached to the right side of the auxiliary frame and are otherwise, except for the perforated front brake disc and the blue strap on the seat, identical to the standard model. Honda had intended the XLV to be a tourer with limited off-road capabilities, it is therefore hard to understand why Honda presented the motorbike to the press on a motocross track. In the early 1980s, most dual-sport motorcycles had only one cylinder and weighed about 120 to 150 kilos - compared to them, the XLV with its 220 kilos seemed to be unfit for sporty off-road driving.

At the launch, several journalists crashed the heavy bike on the motocross track, for which it was unsuited. The XLV750R was Honda's first dual-sport motorcycle with two non-parallel cylinders, it has an air - / oil-cooled V-twin engine with a shaft drive. Those two construction features make the XLV a low maintenance motorcycle. Other technical highlights at the time of introduction were the dry sump lubrication system, the three valves per cylinder, the two spark plugs per cylinder, the crankshaft with off-set pins; the distinctive air scoops mounted below the fuel tank on either side of the motorbike provide additional cooling for the rear cylinder. They were only installed; the XLV was offered in the aggressive colours of the Honda Racing Corporation, namely blue and red, with a red engine, red fork rods and red hubs. This model bears the additional designation "D". In 1985, a revised version of the XLV750R was introduced, bearing the additional designation "F"; the XLV750R-models were improved in some details and had a black engine and golden rims with black hubs.

These motorcycles were painted in the colour combinations black/blue metallic, black/red metallic and black/silver grey and were marketed in Italy and Australia. Honda never offered them in Germany because the demand was low due to the negative press the XLV had received there. In 1986, the production of the XLV750R was discontinued; the RD-genealogy was continued with the chain driven models NX650 Dominator, XRV650/750 Africa Twin, XR650L, SLR650/FX650 Vigor, XL650V/XL700V Transalp and FMX650. The type designation "RD05" was not assigned. Due to its low production numbers of no more than 10,000 units worldwide, the XLV750R is quite seen - and in many countries outside of Europe and Australia, it is an rare bird

Children of Earth is the banner title of the third series of the British television science fiction programme Torchwood, which broadcast for five episodes on BBC One from 6 to 10 July 2009. The series had new producer Peter Bennett and was directed by Euros Lyn, who had considerable experience on the revived Doctor Who. Torchwood is a series about an organization known as Torchwood which defends the Earth against alien threats; the plot of Children of Earth deals with aliens demanding the Earth's children, a related earlier conspiracy. The first and fifth episodes of the serial were written by executive producer Russell T Davies, who conceived its overall storyline; the third episode was co-written by James Moran whilst the second and fourth were penned by newcomer John Fay. Torchwood was shown on the network's premiere channel, BBC One, every weeknight for one week in July 2009. Despite the move to BBC One, the show was cut from a standard thirteen-episode run to just five, something that lead actor John Barrowman felt was like a "punishment" from the BBC.

Production on the mini-series began in August 2008, Barrowman along with actors Eve Myles, Gareth David-Lloyd, Kai Owen all returned. The serial features new actors to the series over the course of its five episodes, most prominently Peter Capaldi. Davies had to rewrite parts of the serial to accommodate the unavailability of actors Freema Agyeman and Noel Clarke, whose presence in the serial had been set up in the 2008 Doctor Who finale; when the series defied expectations by achieving good ratings, Davies stated that a surprised BBC Controller rang to congratulate him. Mid-summer evenings are considered a graveyard slot for television series; the serial received positive reviews in comparison to the programme's previous two series, as well as a BAFTA Cymru Award, a Saturn Award and Celtic Media Festival Award, all for best serial. A number of fans were upset by the death of Ianto Jones in the fourth episode of the serial, with some campaigning and raising money for charity in an attempt to persuade the writers to bring back the character in future.

The success of the series led a fourth series, Torchwood: Miracle Day, commissioned in conjunction with the US premium cable network Starz. Over the course of two days, all the children in the world are paralyzed in place several times, speak in unison, in English, in temporal order based on the hour, a message revealed in stages, one word at a time: "We are coming back tomorrow." Home Office Permanent Secretary John Frobisher is aware these events are tied to an alien race known as the 456, named after the radio frequency they used to communicate the first time they came to Earth in 1965. At that time, in secret, the 456 had given the British government a cure to a new strain of Indonesian flu, otherwise destined to wipe out 25 million people—in exchange for twelve children. Captain Jack Harkness had been one of four British agents who were chosen to give the children to the 456, since public knowledge of the exchange would now be disastrous for the British government, Frobisher orders, through a black-ops department run by an Agent Johnson, the assassination of those four agents.

To this end, Agent Johnson plants a bomb in Jack's abdomen, which detonates inside the Torchwood Hub in Cardiff, destroying it. Aware of Jack's regenerative abilities, Johnson's troops collect Jack's remains from the blast rubble, lock them in a secure facility, monitoring the regeneration of his body. Torchwood employees Ianto Jones, Gwen Cooper, by extension, her husband Rhys, due to the possibility that they might share Harkness's knowledge, are put on Agent Johnson's "kill" list. In the meantime, Frobisher orders the construction of what will turn out to be an "isolation tank" inside Thames House, decreed by information transmitted to them by the 456 when the children first began to speak of their arrival; the remaining Torchwood team make contact with Lois Habiba, a new personal assistant in Frobisher's office who has covertly accessed computer information on Torchwood and the assassinations. Lois helps the others to rescue Jack. Torchwood identifies and rescues Clement MacDonald, one of the original twelve children sacrificed to the 456, but who escaped by running away.

Clement went mad soon after escaping, has been institutionalised for over 40 years since. On the third day, the ambassador for the 456 arrives in a column of fire over Thames House before appearing in the isolation tank. Frobisher and his staff, including Lois who still wears the Torchwood contact lenses, hold confidential meetings with the 456 to understand why they have returned; the 456 demand that 10% of the world's population of children be handed over to them, or else they will destroy the human race. They reveal one of the children from 1965, now a shrivelled husk despite having not aged. Children