Berlin, November, 1926
Volume 1: Generalities
Berne,
International Office of the Telegraph Union,
March, 1927
English translation by Eric Fischer, enf@pobox.com
The session is opened at 10:20.
The minutes of the third session are read and adopted.
Mr. Lange, the delegate from France, gives a reading of the report of the subcommittee charged with studying the question of the speeds of transmission.
This report, of which the text is below, is adopted:
Speed of transfer of a telegraph line
The International Telegraph Committee,
Considering:Advises:
- That the diversity existing in the manner of determining the speed of transfer of a telegraph line is an inconvenience for international relations;
- That the definition adopted for the speed of transfer may be applied to a system of which all the equipment is not in a perfect state of function;
- That at the same time it does not take into account either the different average length of words in different languages, or punctuation, or longer or shorter spaces between words, or the lesser or greater skill of operators;
- That, following these considerations, it is not possible to treat in a single manner all the important systems in use for international relations;
- That, nevertheless, it is possible to divide the current systems into two principal classes:
- The systems characterized by elements of transmission of a duration equal to an elementary interval or a multiple of this interval (systems employing the Morse code or a code of five units; step-by-step systems)
- Synchronous systems founded on the time difference between two successive emissions (Hughes).
- That the speed of transfer be expressed, for the systems of the first class, by the inverse of the value of the elementary interval, expressed in seconds;
- And, for the systems of the second class, by the number of turns per minute of the axis of the typewheel;
- That the speed of transfer of one interval per second be equal to 1 baud, to honor the memory of the great telegrapher Emile Baudot.
- For systems of the first class, the annex makes known the relationship between the speed of transfer that has just been defined and the indications habitually used in practice to characterize the efficiency of a transmission.
Annex
For the Wheatstone apparatus, the speed of transfer in bauds is equal to the number of direction holes per second, multiplied by two.
For the siphon recorder, the number of direction holes per second is equal to the number of bauds.
For Baudot, Murray, Siemens, and Western Union equipment, it is necessary to multiply the number of turns per second by the number of segments to obtain the speed of transfer in bauds.
For start-stop equipment, the number of turns per second is multiplied by the number of emissions necessary for a character.
For indications of a speed of transfer, one word is equal to five characters plus a space = 6 characters; 20 English feet of Wheatstone punched tape = 100 words; 12 English inches = 5 words.
The number of cycles per second is equal to the number of bauds.
Considering in the second place:
- That to calculate the probable speed of a transmission of a projected connection, it is necessary to know the elements of this connection and thus a certain number of exterior factors;
- That many methods have been proposed to this effect, which imply the knowledge of empirical coefficients:
Advises:
- That some reporters be named by the committee to study this question;
- That the administrations furnish to these reporters all the information that they possess on this subject.
The president expresses the general sentiment of satisfaction that the assembly demonstrates for this decision, which honors the memory of an eminent member of the family of telegraphers. Mr. Boulanger thanks the president, and thus the assembly, in the name of the French Administration and of the old collaborators of Baudot present: Messrs. Montoriol and Carrat.
(Lively applause)
It is decided that the German, French, British, and Italian administrations will designate reporters to study the question that is the object of the opinion that has just been adopted.
Mr. Lazar, delegate from Hungary, wishes that the attention of the administrations be called to the utility of a tight collaboration between them, every time anyone envisions laying a long distance telephone cable that is susceptible to being used for telegraphy.
The president does not doubt that this wish will be taken into consideration by the assembly, all the more that this recommentation seems to be implicitly continued in the considerations of the opinion that it gave in the previous session.
(General assent)