Apparatus utilizing a phantom circuit for connecting additional subscribers to a telecommunication system

• US 3,975,594 A
• Filed: 02/10/1975
• Issued: 08/17/1976
• Est. Priority Date: 12/20/1971
• Status: Expired due to Term

• Current Assignee: Siemens AG
• Original Assignee: Siemens AG
• Inventors: Guntersdorfer, Siegfried
• Primary Examiner(s): Stellar, George G.
• Application Number:
  US05/548,671
• Time in Patent Office: 554 Days
• Field of Search: 179/2.5 R, 179/15 BB, 179/4, 179/2 TV, 179/170 J
• US Class Current: 370/200
• CPC Class Codes: H04B 3/44 Arrangements for feeding power to a repeater along the transmission line
• CPC Class Codes: H04L 5/20 using different combinations of lines, e.g. phantom working
• CPC Class Codes: H04M 11/08 specially adapted for optional reception of entertainment or informative matter
• CPC Class Codes: H04M 7/08 for phantom working phantom working in transmission of digital information H04L5/20
• CPC Class Codes: H04Q 3/00 Selecting arrangements H04Q5/00 - H04Q11/00 take precedence

Abstract

A subscriber line circuit for telecommunication systems in which additional message signals, e.g., video signals, can be transmitted is described. The line circuit is constituted by two balanced line pairs which, if necessary, can have line amplifiers interposed therein. A remote supply circuit for the amplifiers, constructed in the form of a phantom circuit, is used, and this phantom circuit is used, as well, as the transmission circuit for the additional message signals. A subscriber set for the additional message signals is connected to the phantom circuit. A feed to the latter subscriber set, as well as two way communication take place over the phantom circuit.

Claims

1. In telecommunication systems wherein line connections from a subscriber set to an exchange switching center are made over two balanced line pairs which additionally form a phantom circuit providing a path for a remote power source, the improvement comprising:

additional subscriber set means connected to said phantom circuit at the location of said subscriber set so that a two-way message path is formed between said additional subscriber set and said exchange switching center over said phantom circuit and a conducting path is formed between said remote power source and said additional subscriber set and

branch circuit means connected to said phantom circuit and including said remote power source, means for coupling audio signals to said phantom circuit and means for coupling control signals to said phantom circuit.