Deutsche Bundespost Research Articles

Large systems: EWS: Germany's answer to ESS: Stored-program control is at the heart of the Deutsche Bundespost's electronic telephone switching system

Stored-program control is at the heart of the Deutsche Bundespost's electronic telephone switching system.

A Digital Hybrid Transmission System for 280 Mbits/s and 560 Mbits/s

This paper presents the development of repeaters and line equipment for an experimental digital long-haul transmission system using coaxial cable. A comparison, of different types of digital transmission systems indicates that the digital repeater hybrid system with binary transmission code is the most desirable. This development has resulted in digital pulse reshaping repeaters with very small dimensions, low cost, and good reliability. Both digital repeaters that are without timing and regenerators that include timing have been developed. Their circuitry and the corresponding signal shapes are described. The dc power-feeding system and the fault-location system are also discussed. An experimental field trial with the Deutsche Bundespost was performed over 10-repeater sections of the International Telephone and Telegraph Consultative Committee (CCITT) normal coaxial tube with a section length of 1/2 mi, The experiments confirmed that a long-haul digital transmission system of 560 Mbits/s, and later of 1100 Mbits/s using the described system concept and technology, can be established with relatively low cost and good reliability.

Present State and Trends of Public Communications in the Fedearal Republic of Germany

The introduction gives an account of the historical development of telecommunications in Germany (Federal Republic of Germany), the legal status of the Deutsche Bundespost, its relationship with the German telecommunication industry, and the status of the broadcasting organizations. On the basis of the present state of the art, the future trends in switching and transmission as well as in cable and radio engineering are described. Of special weight are the new data and telephone switching systems and the requirements for future broad-band services. Research and development are concentrated on these projects, allowance having to be made for the present state of the networks in the Federal Republic of Germany.

Plans for data communications in Germany

The Electronic Data Switching system (EDS) and its introduction into the network of the Federal German Post Office are presented. The great demands of future data transmission will be unable to be met by conventional techniques. Therefore, special networks for data traffic are being discussed in several countries. This paper deals with the plans of the Deutsche Bundespost (Federal German Post Office) to establish a data network by making use of the newly developed EDS system. Furthermore, it describes the individual components of the network, such as the connection of the subscriber and the techniques for transmission, concentrating, and switching. The new network will offer a great number of operational and technical facilities which cannot be provided using conventional techniques. Starting from the present international agreements, the most important operational facilities of the data network are described, and an outlook is given on future synchronous modes of operation with the EDS system.