Intercom

“ In fact it may be said that telephonic speech is now possible over any length of wire circuit. Speech through submarine cables is, however, still limited to comparatively short distances.
The most important application of the telephone repeater, and one in which the greatest economies are possible, is in the internal communications of a country. For instance, in order to provide telephonic communication between, say London and Manchester, Leeds, Newcastle and Glasgow, it has hitherto been necessary to erect line conductors weighing on the average 600 lb. per circuit mile. ”

“ These people never entirely get over this feeling and many of them have station equipment which in the hands of an operator with more nerve, could do wonders; For this reason, any plan which calls for initiative on the part of all stations in a voluntary organization such as the Relay League, is bound to be only partially effective.
The next question in undertaking to grasp the practical necessities, is that of regular trunk lines. In order to have system in either traffic in messages or traffic in
portation, it is necessary that there shall be established routes. ”

“ The term “Corporation” means the Corporation for Public Broadcasting authorized to be established in subpart D. The term “interconnection” means the use of microwave equipment, boosters, translators, repeaters, communication space satellites, or other apparatus or equipment for the transmission and distribution of television or radio programs to public telecommunications entities. The term “interconnection system” means any system of interconnection facilities used for the distribution of programs to public telecommunications entities. ”

“ In cases where the traffic between communities is large, where the rate is small, and where the conversations are short and more on the general order of local calls, it is usual to handle the switches exactly as local calls are trunked between central offices of the same exchange. That is, the subscriber's operator who answers the call trunks it, by the assistance of a call circuit and an incoming trunk operator. ”

“ BELL SYSTEM TELEVISION NETWORK ROUTES JULY 1, 1955
Color and Monochrome Available To Cities On These Routes Routes Equipped For Monochrome Only Planned Other “Custom-tailored” services
Long Lines and the operating companies also provide extensive private line services—that is, service for customers who have a large enough volume of communications between two or more points to need facilities for their exclusive use, tailored to their individual requirements. The private line services are provided by means of both wire and radio, for a specified period of time and usually on a recurring basis. ”

“ Where the long-distance traffic between two communities is large, economy requires that the sending of signals by ringing over the line, waiting for an answer, and then reciting the details of the call, be improved upon. If the traffic is large and the distance between communities small, call circuits are established in the same way as between the switchboards in several manual central offices of an exchange. The long-distance operator handling the originating call passes the necessary details to the distant operator by telephone over the call circuit. ”

“ Thank God the cable has been successfully laid and is in perfect working order. I am sure that no one will be as thankful to God as you and our dear children. Now we shall be a united family. We leave in about a week to recover the cable of last year. Please telegraph at once and write in full, and I shall receive your letters on my return here.
“On the 15th inst. I received through the cable from Valentia your message from Newport and Grace’s telegram from Newburg, and on the 22d inst. your telegraphic despatch of the 10th inst., and this moment your letter of the 12th inst. ”

“ Bell himself was perhaps the first to see the future of the telephone exchange. In a letter written to some English capitalists in 1878, he said: "It is possible to connect every man's house, office or factory with a central station, so as to give him direct communication with his neighbors.... It is conceivable that cables of telephone wires could be laid underground, or suspended overhead, connecting by branch wires with private dwellings, shops, etc., and uniting them through the main cable with a central office." ”

“ The circuit is provided with through-line ringing of a type which is free from interference and there is a superimposed telegraph circuit capable of forming a link in a duplex wire telegraph circuit. The volume and quality of telephone transmission are so good that the radio link is regularly connected, whenever required, with long-distance wire circuits. ”

“ Kurt said. “But seriously.”
“Seriously,” Lyman said. “Seriously. Think a second about the scale of a telco. Of this telco. The thousands of kilometers of wire in the ground. Switching stations. Skilled linesmen and cable-pullers. Coders. Switches. Backhaul. Peering arrangements. We’ve got it all. Ever get on a highway and hit a flat patch where you can’t see anything to the horizon except the road and the telephone poles and the wires? Those are our wires. It’s a lot of goodness, especially for a big, evil phone company. ”

“ Suppose you were to walk into the office and say the Eastern line of cable had broken down. As the Western line is under repair that tells me that communication with South Africa is impossible for a day or more. Probably the lines would be unavailable for nearly a week. I've got a spare envelope or two used by the Eastern Company for their messages; I put this flimsy inside and alter my own address 'Bonan' to 'Bonanza'—which is the registered cable address of The Messenger—by the addition of two letters, and there you are. ”

“ It is not practicable to connect each subscriber directly to all the others, hence a -system of exchanges has been adopted. The territory in which a telephone administration operates is usually divided into a number of local areas, in each of which one or more exchanges are placed. An exchange is a central station to which wires are brought from the various subscribers in its neighbourhood, any two of whom can be put in telephonic communication with each other when the proper pairs of wires are joined together in the exchange. ”

“ I feel that the toast which I have the honour to propose deserves a foremost place in the toasts of the day, and that you will heartily respond to it, namely, Success to the Telegraph Construction and Maintenance Company, for that Company has laid scores of cables since its formation, and has now successfully commenced, and will doubtless triumphantly complete, the laying of the cable which we have met to celebrate to-day—the fourth great enterprise, I may remark, which the Company has undertaken—the cable that is soon to connect India with England. ”

“ The transfer, however, has been a great boon to the nation, and has enabled the postal and telegraph system of Great Britain and Ireland to become the largest and most complete organisation for the transmission of messages in the world. The immense increase in business would, however, have been impossible but for the advances made since the transfer in telegraphic apparatus, and in wire values, such as the introduction of the duplex, quadruplex, and multiplex systems, which allow of a single wire being electrically split up for the simultaneous transmission of a number of currents. ”

“ Traditionally, transmission capacity has been offered for discrete services, such as telephone service. With the incorporation of digital technology into the telephone network and the inclusion of computer processing capabilities into both terminal equipment located in the customer's premises and the equipment making up a firm's "network," this is no longer the case. Telecommunications service is no longer just "plain old telephone service" to the user. A subscriber may use telephone service to transmit voice or data. ”

“ The growth of traffic on this basis has been considerable, and the arrangement has proved of advantage to the public, as it provides cheap facilities at times which are convenient for social conversation. Telephone subscribers may telephone ordinary messages to any post office which may be reached through the local exchange system, or by means of the trunk wires, in order that the messages may be written down and forwarded as telegrams or express letters or ordinary letters. ”

“ When in the middle of the nineteenth century the human race had achieved a degree of development that made swift communication essential to the common life, the telegraph and the ocean cable were invented; or it might rather be said, the laws that make them possible were discerned, and were taken advantage of to utilize for this purpose. The constant developments in rapid transit, in the instantaneous conveniences of telephonic communication, and, latest of all, in wireless telegraphy, are all in the line of absolute correspondence with the advancing needs of humanity. ”

“ Twenty-three years ago the first telephone exchange in the world was established in the United States, and from that beginning has been built up the great system of exchanges, and the network of connecting lines over which conversation can be held between points over a thousand miles apart. ”

“ Without going into details, I shall merely say that the great defects of this plan of multiple telegraphy were found to consist, firstly, in the fact that the receiving operators were required to possess a good musical ear in order to discriminate the signals; and secondly, that the signals could only pass in one direction along the line (so that two wires would be necessary in order to complete communication in both directions) . ”

“ Telephone system: an inadequate system, further limited by poor maintenance; major expansion is required and a start has been made domestic: intercity traffic is carried by coaxial cable, microwave radio relay, a domestic communications satellite system with 19 earth stations, and a coastal submarine cable; mobile cellular facilities and the Internet are available international: satellite earth stations - 3 Intelsat (2 Atlantic Ocean and 1 Indian Ocean) ”

“ The grey matter may be compared with a telephone exchange, where, from moment to moment, though the end-points of the system are fixed, the connexions between starting-points and terminal points are changed to suit passing requirements, as the functional points are shifted at a great railway junction. ”

“ Railways and steamships had begun this work of binding man to man by "nobler and cunninger methods." The telegraph and cable had gone still farther and put all civilized people within sight of each other, so that they could communicate by a sort of deaf and dumb alphabet. And then came the telephone, giving direct instantaneous communication and putting the people of each nation within hearing distance of each other. ”

“ Everybody asks the question, “How far can I speak on the telephone?” In this country at least that will ultimately depend on the way the difficulties of the submarine cable are surmounted. You can talk in England to Paris and Brussels and many provincial towns in France and Belgium. The new cable has enabled telephonic communication to be made between Paris and Glasgow: Manchester can speak to Paris, Nottingham to Lyons, and Ipswich to Bordeaux. The engineers of the Post Office talk of the possibility of a conversation between London and Astrachan. ”

“ You must have a modem ——————————- Some computers are always connected to a network. If this is your situation, then you probably have what you need already. The rest of us need a modem. A modem is a small piece of equipment that is translating the internal, electrical signals of the computer to sound codes. These codes can be sent over an ordinary telephone line. You may think of it as a type of Morse alphabet. The recipient of data also needs a modem. ”

“ The making up of connections between a long-distance and a local line is usually done by means of operators other than those employed in handling the local calls, who work either by means of special equipment located on the local board, or by means of a separate board. ”

“ If we had such trouble in a land line, how should we get a connection from London to the Gibraltar cable through lines in constant use?
"But," said Airy, "I never allow an operator who can speak with the instruments to take part in determining a telegraphic longitude."
"Then how can you get the connections all made from one end of the line to the other, at the same moment, if your operators cannot talk to one another?"
"Nothing is simpler. I fix in advance a moment, say eight o'clock Greenwich mean time, at which signals are to commence. ”

“ Yet back to these cheaply constructed subscriber-lines and that crude equipment is easily traced the origin of the marvelous system of intricate switchboard mechanism, practical and standardized methods, and progressive operation known as the modern telephone exchange, and by the aid of which a subscriber in New Haven may now talk with greater ease to a subscriber in Pittsburg, or in Chicago, than was possible when the two subscribers were distant only a block away on wet pioneer days in Connecticut. ”

“ Bell telephone installer connects drop wire to new subscriber’s home.
Most wire in city telephone cables lies underground in tile conduits and comes into the telephone office through a cable vault in the basement. If the 7 city has more than one central office, trunk cables interconnect the offices.
At each telephone office the cables run to the terminal room, where their hundreds or thousands of pairs of wires fan out to terminal blocks on one side of a large distributing frame. Other wires run from the opposite side of the distributing frame to the switchboard or dial equipment. ”