Circuit arrangement for telecommunication switching systems, particularly PCM-time-division multiplex telephone switching systems with a central matrix and with local sub-switching matrices connected to the same

US4901347A · kind A · utility

Assignee

• Siemens Aktiengesellschaft · DE

Inventors

• Lothar Schmidt · Bochum, DE
• Klaus Eberlein · Wolfratshausen, DE
• Gerhard Schaich · Munich, DE
• Fritz Hlawa · Deisenhofen, DE

Key dates

• Filing date: May 23, 1988
• Grant date: Feb 13, 1990
• Expiry date: May 23, 2008

Classification

• Technology area (CPC H): Electricity
• CPC primary: H04Q11/0407
• WIPO field: Telecommunications
• WIPO sector: Electrical engineering

Abstract

A circuit arrangement for telecommunication switching systems, including PCM time division multiplex telephone switching systems, with double central switching matrix by which two corresponding line trunk groups comprising a sub-switching matrix each and a group control unit each, are allocated to each other in pairs via two time-division-multiplex lines. The line units and the PCM-lines leading to the central switching matrix, which are individually respectively allocated to the two line trunk groups, and which are connected with the respective sub-switching matrix of their own 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 calls already interconnected via the line units of the affected line trunk group up to the time of the switch-over are interrupted, each local control unit transmits all call data of interconnected calls to its associated control unit while still in normal service, on which basis the appertaining calls are securely interconnected within the sub-switching matrix of the associated line trunk group.