Alarm and test system for a digital added main line

Year	Description
1990	Invention patented by David C. Bliven, Anthony Vranicar, Philip B. Vail, Gerald L. Shimirak, and Julian S. Mullaney on September 16th, 1990. Abstract: A test system directed to apparatus for transmitting and receiving multiple telephone transmission signals over a single twisted pair. The system converts an analog signal from a local switching station to an 80 ksymbols/sec signal for transmission over a twisted pair by a line card. A remote terminal converts the 80 ksymbols/sec signal back into a conventional analog signal for use in conventional telephone, facsimile or other related equipment. The test equipment separately tests the entire system, the line card portion of the system, the remote terminal portion of the system, and the twisted pair.
Source: selected by the editor from original sources.

Invention: Alarm and test system for a digital added main line