Digital repeater with 3-way branching of service channels

• US 4,667,319 A
• Filed: 07/29/1985
• Issued: 05/19/1987
• Est. Priority Date: 07/29/1985
• Status: Expired due to Term

• Current Assignee: US Sprint Communications Company A New York General Partnership
• Original Assignee: GTE Telenet Communications Corp. (Verizon Communications Inc.)
• Inventors: Chum, Stanley P. K.
• Primary Examiner(s): Olms, Douglas W.
• Assistant Examiner(s): Kuntz, Curtis
• Application Number:
  US06/759,716
• Time in Patent Office: 659 Days
• Field of Search: 370/55, 370/97, 370/110.1, 370/58
• US Class Current: 370/260
• CPC Class Codes: H04J 3/08 Intermediate station arrangements, e.g. for branching, for tapping-off

Abstract

A novel 3-way digital branching network located at a telecommunications repeater branches digital service channel signals into and out of the digital transmission system. On the drop side a first adder combines the West-to-East and East-to-West digital service channel signals before being converted to analog signals for use by the local service channel equipment. On the insert side the locally generated service channel signals are digitized and then digitally combined with the through path signals by a second and third adder for insertion into the West-to-East and East-to-West digital transmission paths.

Claims

1. In a digital communication transmission system including a transmission facility having a service channel, first and second receive ports for providing demodulated service channel signals from separate transmission paths, and first and second transmit ports for providing service channel signals to separate transmission paths, apparatus at a repeater for branching digital service channel signals into and out of the transmission system, said apparatus comprising:

A/D conversion means for converting analog input signals from local service channel facilities to digital output signals;

D/A conversion means for converting digital input signals into analog output signals for reception by said service channel facilities;

first adder means having first and second inputs and a first output, said first input connected to said first receive port, said second input connected to said second receive port, and said first output connected to said D/A conversion means, said adder means performing a digital addition of the received service channel signals at said first and second inputs;

second adder means having third and fourth inputs and a second output, said third input connected to said first receive port, said fourth input connected to said digital output signals from said A/D conversion means, and said second output connected to said second transmit port, said second adder means performing a digital addition of said locally generated service channel signals with said service channel signals from one of said transmission paths;

third adder means having fifth and sixth inputs and a third output, said fifth input connected to said second receive port, said sixth input connected to said digital output signals from said A/D conversion means, and said third output connected to said first transmit port, said third adder means performing a digital addition of said locally generated service channel signals with said service channel signals from the other of said transmission paths.

2. Apparatus as in claim 1 wherein each of said adder means further comprises a binary adder coupled to a buffer.

3. In a digital communication system having a voice/ data service channel facility, a West terminal, an East terminal, and a repeater including an East-to-West and West-to-East digital transmission system, apparatus at the repeater for digitally coupling the digital through path service channel signals to the corresponding East-to-West and West-to-East path transmission systems, and for coupling the drop and insert signals with the East-to-West and West-to-East path transmission equipment, said interface apparatus comprising:

means for dropping said service channel signals from said W-E and E-W transmission system to the service channel repeater facility, said dropping means comprising;

first adder means responsive to the digital signals from said W-E transmission system and said E-W transmission system for generating a digital

signal representative of the sum of the West-to-East and East-to-West drop service channel signals;

D/A conversion means responsive to said summed West-to-East and East-to-West drop service channel signals for generating an analog drop signal representative of the sum of the West-to-East and East-to-West drop service channel signals;

means for combining said service channel signals from said repeater facility with said West-to-East and East-to-West service channel through path signals for insert into said West-to-East and East-to-West transmission system, said combining means comprising;

A/D conversion means responsive to the analog insert service channel signals from said repeater facility for generating a digital insert signal representative of the analog insert service channel signals;

second adder means responsive to the digital insert signals and the West-to-East through path service channel signals for generating a digital signal representative of the sum of the West-to-East through path service channel signals and the digital insert signals for connection to said West-to-East repeater transmission equipment; and

third adder means responsive to the digital insert signals and the East-to-West through path service channel signals for generating a digital signal representative of the sum of the East-to-West through path service channel signals and the digital insert signals for connection to said East-to-West repeater transmission equipment.

4. Apparatus as set forth in claim 3 wherein said D/A conversion means further comprises a digital-to-analog converter.

5. Apparatus as set forth in claim 3 wherein said A/D conversion means further comprises an analog-to-digital converter.

6. Apparatus as set forth in claim 3 wherein said first, second, and third adder means each further comprises a binary adder.