US 4,449,218 A · Analog/digital telecommunication subscriber station

Abstract

An analog/digital telecommunication subscriber station is connectible to a two-wire line and comprises a frequency multiplexer and a frequency demultiplexer for grouping and fanning an analog communication channel covering the telephone band and a digital communication channel lying above the telephone band. The station further comprises a hybrid for connecting the two-wire line into a four-wire line. The subscriber station is particularly characterized in that the two-wire line is terminated by a broad-band hybrid which is proceeded in the transmission branch by a frequency multiplexer which groups at least the analog communication channel covering the telephone band and the digital communication channel lying thereabove, and is followed in the receiving branch by a frequency demultiplexer which fans at least the analog communication channel covering the telephone band and the digital communication channel lying above the telephone band. Various embodiments provide analog telephone operation, digital telephone operation, fast data operation, slow data operation, picture telephone service and a combination of analog and digital two-party line as various options.

Claims20

Dependent claims

An analog/digital two-party line system for connection to a two-wire line, comprising:

a frequency multiplexer including a multiplex signal output, an analog signal input and a digitial signal input and operable to multiplex analog signals in the telephone band and digital signals in a predetermined band outside of the telephone band;
a frequency demultiplexer including an analog signal output, a digital signal output and a multiplex signal input, and operable to demultiplex analog signals in the telephone band and digital signals in the predetermined band outside of the telephone band;
a broad-band hybrid including a two-wire input/output for connection to a two-wire line, a transmission branch connected to said multiplex signal output of said multiplexer, and a receiving branch connected to said multiplex signal input of said demultiplexer;
a digital transmission circuit connected to said digital signal input of said multiplexer;
a digital receiving circuit connected to said digital signal output of said multiplexer;
a first telephone transmitter and a first telephone receiver respectively connected to said analog signal input and said analog signal output;
an encoder and a decoder respectively connected to said digital transmission and receiving circuits;
and
a second telephone transmitter and a second telephone receiver respectively connected to said digital transmission and receiving circuits.

6 more elements

An analog/digital subscriber line system for connection to a two-wire line, comprising:

a frequency multiplexer including a multiplex signal output, an analog signal input and a digital signal input and operable to multiplex analog signals in the telephone band and digital signals in a predetermined band outside of the telephone band;
a frequency demultiplexer including an analog signal output, a digital signal output and a multiplex signal input, and operable to demultiplex analog signals in the telephone band and digital signals in said predetermined band;
a broadband hybrid including a two-wire input/output for connection to a two-wire line, a transmission branch connected to said multiplex signal output of said multiplexer, and a receiving branch connected to said multiplex signal input of said demultiplexer;
a digital transmission circuit connected to said digital signal input of said multiplexer;
a digital receiving circuit connected to said digital signal output of said multiplexer;
a first telephone transmitter and a first telephone receiver for respective connection to said analog signal input and said analog signal output of said multiplexer and said demultiplexer, respectively;
an encoder and a decoder for respective connection to said digital transmission and receiving circuits;
a second telephone transmitter and a second telephone receiver respectively connected to said analog signal input of said multiplexer and said analog signal output of said demultiplexer;
a first data terminal;
a modem connected to said first data terminal and including an input for connection to said analog signal output of said demultiplexer and an output for connection to said analog signal input of said multiplexer;
a second data terminal including an input for connection to said digital receiving circuit and an output for connection to said digital transmission circuit;
and
switching means selectively operable to selectively connect said modem, said first telephone transmitter and receiver and said second data terminal to said multiplexer, said demultiplexer and said digital transmission and receiving circuits.

10 more elements

Dependencies are inferred from the claim text.

Analog/digital telecommunication subscriber station

Life of this patent

Analog/digital telecommunication subscriber station

Life of this patent

Abstract

Claims20