Patent · US Expired

Telephone exchange system

US5404398A · kind A · utility

5Cited by
10References
17Claims
0Family size

Assignee

Inventors

Key dates

Filing dateSep 1, 1993
Grant dateApr 4, 1995
Priority date
Expiry dateSep 1, 2013

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04M3/42
  • WIPO fieldTelecommunications
  • WIPO sectorElectrical engineering

Abstract

A telephone exchange system useful for a bank or brokerage house speech system or the like, which can accommodate a large number of lines (or trunks) and permit improvement of the reliability and call connection processing capacity. The system comprises exchange sub-systems A (EX-A) and B (EX-B) capable of independently executing an exchange operation and each accommodating a terminal. The terminal, on the other hand, has a speech channel switch for connecting a speech channel including a handset to either exchange sub-system A (EX-A) or B (EX-B). When a process of connecting a call is brought about in the terminal, that terminal selects one of the exchange subsystems and controls the speech channel switch for connecting the call to the selected exchange sub-system.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.