Long-Distance Communications

Long-Distance Communications

 

telephone and telegraph service over wire and radio systems between correspondents located at great (virtually unlimited) distances from each other. The term “long-distance communications” arose in the technology of transmission of electrical signals over wire communications lines; a synonym is “intercity communications,” and an antonym is “local communications” (within a city or raion).

Telephone, telegraph, phototelegraph, and television signals are transmitted simultaneously over long distances over air, cable, and radio communications lines in which hundreds or thousands of independent communications channels are formed by multiplexing communications lines. The use of artificial earth satellites for long-distance communications is promising. To compensate for signal attenuation, attended and unattended (remote-controlled) repeater stations or relay stations with amplifiers for the transmitted signals are installed on some sections of long-distance ground lines. For deep-sea (cable) long-distance communications unattended repeaters with long service life are installed at certain intervals along the length of the cable. Reliable continuous communications are ensured by the use of standby equipment and automated long-distance communications lines.

N. M. IZIUMOV

References in periodicals archive ?
The integrated solution - which utilises Sepura's NEBULA infrastructure and EN50155 onboard equipment - will provide a cost-effective alternative for operators utilising long-distance communications networks to control ETCS-enabled trains.
NEC's simulation trials of the newly developed AAS, which adopts beamforming, a technology for transmitting radio waves in multiple directions (to objects) while intensively and simultaneously using many antenna elements, achieved up to one kilometer in long-distance communications in 16 respective directions on 28GHz high radio frequency bands, at a communications speed of 30Gbps or faster per cell, and spectral efficiency 20 times greater than LTE on a per-communication area basis.
GE Digital Energy has announced the MDS SD2, a software-controlled digital radio that is said to provide long-distance communications over licensed radio bands and allow users to deploy IP/Ethernet and serial communications using 200 MHz.
The new network will provide high-speed, high-bandwidth communication services and improve the quality and availability of long-distance communications for Kazakhstan's corporate and private users.
Furthermore, you have access to features such as the ability to carry phone traffic over US- or European-based IP providers as well as to interconnect branch offices in different cities over the Internet without having to pay long-distance communications charges, both of which are very big financial wins.
Although many long-distance communications cables are now made of fiber-optic material and therefore aren't susceptible to currents induced by solar flares, the signal-amplifying equipment used on such networks receives its power via long metallic wires that could carry such currents, Jansen and Pirjola note.
Morse did become a prosperous artist, but when his most ambitious, meticulously detailed works failed to establish him as a serious painter, he decided to concentrate on the inventions, including an idea for a long-distance communications device.
The technology behind this lesson worked just as naturally and effectively as the long-distance communications I am accustomed to seeing on television when I watch Star Trek.
WorldCom, the troubled long-distance communications company, hopes to introduce Capellas as its new chairman and chief executive as soon as today, people involved in WorldCom's executive search said on Thursday.
in February 1999, making long-distance communications considerably more difficult, especially for Cuban families divided across the Florida Straits.
Long-distance communications will cease to be a viable standalone business, forcing long-distance transport providers to integrate end-to-end services in order to compete for the customer.
The contract takes the Marconi equipment into the state of Parana and the Coventry company will also supply a long-distance communications system for Brazil's second most industrialised region.