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United States Patent | 3,824,597 |
Berg | July 16, 1974 |
Disclosed is a transcontinental communications network particularly designed for the very rapid transmission of digital data between subscribers throughout major areas of the United States. The network comprises a microwave trunkline extending from San Francisco downwardly through the center of the country and upwardly to Boston along which data may be transmitted at rates of 4800, 9600, and 14,400 bits per second and higher. Transmission along the trunkline is by phase modulation of a carrier in the 6 MHz and 11 MHz band. Time division multiplexing provides a minimum of 4,000 channels utilizing a relatively small bandwidth of the frequency spectrum. The trunklines are under the control of switching centers comprising regional and district offices which allocate channels and handle communications traffic through the network. A microwave cable or optical local distribution system connected to the basic trunkline provides a full duplex operation throughout the network and insures the rapid transmission of data completely throughout the network from one subscriber to another.
Inventors: | Berg; Edward A. (Vienna, VA) |
Assignee: |
Data Transmission Company
(Vienna,
VA)
|
Appl. No.: | 05/088,068 |
Filed: | November 9, 1970 |
Current U.S. Class: | 370/215 ; 370/276; 370/477; 455/3.05 |
Current International Class: | H04B 10/10 (20060101); H04L 27/227 (20060101); H04B 7/155 (20060101); H04B 7/17 (20060101); H04L 5/00 (20060101); H04L 27/20 (20060101); H04L 5/22 (20060101); H04j 003/00 () |
Field of Search: | 325/1,2,3,5,367,13,14,51,53-56,184,305 178/50,58 343/200-204 179/15BD,15AD,15A,15AW,15FD,18R,18FC,15BS 340/147R,147T,150,155,167R 250/199 |
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