Patent · US Expired

Telecommunication switching systems with a central switching and local sub-switching

US4853957A · kind A · utility

8Cited by

2References

2Claims

0Family size

Assignee

Siemens Aktiengesellschaft · DE

Inventors

Helmut Seeger · Wolfratshausen, DE
Axel Leichum · Munich, DE
Anthony Maher · Perrysburg, US

Key dates

Filing date	May 23, 1988
Grant date	Aug 1, 1989
Priority date	—
Expiry date	May 23, 2008

Classification

Technology area (CPC H)Electricity
CPC primaryH04Q11/0407
WIPO fieldTelecommunications
WIPO sectorElectrical engineering

Abstract

A circuit arrangement, with a doubled central switching matrix to which two line trunk groups having a sub-switching matrix each and a group control unit each, are allocated to each other in pairs via two PCM-lines. The line facilities which are individually allocated to the one and the other of the two line trunk groups and which are connected to the sub-switching matrix of their own respective line trunk group during normal service, are switchable during emergency service of one of the two line trunk groups to the sub-switching matrix of the respective other line trunk group. In order that no interconnected calls are interrupted, each local control unit stores the call data of all interconnected calls during normal service. A prepared change-over signal blocks all call-establishing requests and implements the transmission of the call data to the respective associated line trunk group on the basis of which the appertaining calls are interconnected within the sub-switching matrix and respective associated line trunk group, and thus prepared for a change-over.

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