Transfer Scheme

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A transmission plan ( English transmission plan ), formerly damping plan ( Dpl , engl. Loss plan ), is to be maintained for a preset attenuation values of links in the communications engineering .

application

In order to achieve good intelligibility of the transmitted speech, the signal must reach the recipient with sufficient volume . This means that for connections between any subscribers in national and international traffic, the reference attenuation may not exceed a certain value. The distribution of the permissible total reference attenuation over the individual sections of a connection is specified in the transmission plan. These specifications include analog and digital transmission links and those that consist of analog and digital sections. In the transmission plan, all components of the corresponding transmission system are considered and the respective permissible attenuations are specified. The total attenuation is given from telephone receiver to telephone receiver, i.e. for the distance from the acoustic side of the microphone at the transmitter to the acoustic side of the loudspeaker at the receiver. The transmission plan is used by the telecommunications network operators to plan the transmission of the individual network components and their connections.

tasks

Transfer plans serve several purposes, such as: B .:

  • Definition of maximum values ​​and possibly also minimum values ​​for attenuation of different line sections of a communication link.
  • This ensures the maximum permissible total attenuation.
  • Ensuring the operational stability of the individual line sections in different operating states.
  • Definition of the signal level in the network so that overloads and weak signals in the transmission systems are avoided.
  • This results in z. B. with analog connections, ensuring a constant volume for phone calls.
  • Compliance with the recommended specifications of international bodies (standardization) to ensure the quality of cross-network connections.

Examples of transfer plans

Former transfer plan of the Deutsche Bundespost
  • "Attenuation plan 55" of the Deutsche Bundespost: National attenuation plan for the self-dial remote service of the Deutsche Bundespost . The damping plan 55 is historic. It was introduced in 1955, later supplemented and then replaced. "Guideline 151 R 3 attenuation plan 55".
  • "Transmission plan 80" of the Deutsche Bundespost: This expanded damping plan 55 was introduced in 1981. It was almost identical to the damping plan 55 . The attenuation values were now given in dB instead of in Neper .
  • The guideline 1 TR 800 "Guideline for the technical transmission planning of the public telephone network of the DBP - transmission plan -" replaced the previous transmission plans and was introduced in 1986. Many specifications were adopted, but also essential parameters were redefined and values ​​for digital transmission systems were newly recorded.

standardization

To ensure that the transmission quality is guaranteed even when international networks and networks of different telecommunications network operators are interconnected, the network operators must coordinate the network transitions with one another. This is done by means of bilateral agreements, which often refer to the guidelines of international standardization institutions.

  • ITU-T G.101 The transmission plan
  • ITU-T G.121 Loudness ratings (LRs) of national systems
  • ETSI ES 202020 Speech Processing, Transmission and Quality Aspects (STQ); Harmonized Pan-European / North-American approach to loss and level planning for voice gateways to IP based networks

literature

  • Uwe Horn (Hrsg.): Analog transmission technology with techniques for operational processing. 3rd edition, R. v. Decker's, Heidelberg 1984, ISBN 3-7685-0183-3 .
  • Heinz Körber: Basics for telecommunications technicians. 2nd edition, specialist book publisher Dr. Pfanneberg & Co., Giessen 1965.
  • Karl Bergmann: Textbook of telecommunications technology. 5th edition, Schiele & Schön, Berlin 1986, ISBN 3-7949-0405-2 .
  • Standard Elektrik Lorenz AG (Ed.): Pocket book of communications engineering . 3rd edition, Stuttgart 1988, ISBN 3-7949-0477-X .
  • Gerd Siegmund: Network technology. 5th edition, Hüthig, Heidelberg 2002, ISBN 3-8266-5021-2 .
  • Instruction sheets of the Deutsche Bundespost
    • Issue 5 + 6/1956: Attenuation plan 55 for the state long-distance dialing network
    • Edition 3/1966: Attenuation plan 55 for the state long-distance dialing network
    • Volume 34, issue 5/1981, p. 186: Damping plan 55 and its amendment from 1980
    • 39th year, edition 6/1986, p. 295: Transfer plan
    • 41st year, edition 8 + 9/1988, p. 347: Transfer plan
    • 41st year, edition 11/1988, p. 497: Practical application of the transfer plan

Individual evidence

  1. ↑ Gerd Siegmund: Technology of Networks 5th Edition, p. 124
  2. ^ Karl Bergmann: Textbook of telecommunications technology. 5th edition, p. 512
  3. ^ Educational sheets of the Deutsche Bundespost, Issue B Telecommunications: Attenuation plan 55 and its supplement from 1980 5/1981, p. 186
  4. ↑ Uwe Horn: Analoge Transmissionstechnik Postleitfaden, 3rd edition, RvDecker's Verlag, p. 38
  5. ^ Educational sheets of the Deutsche Bundespost, Issue B Telecommunications: Transfer plan 6/1986, p. 295