џWPCL ћџ2BJ|xа АH аа АА X агга ХА6p&А6p&Х аеЄ† а Hр аааУ Уб cмˆ4 PŽТ б Fascicle VII.2 Р-Р Rec. U.3 PAGE1 Єее~† а HH аааУ Уб cмˆ4 PŽТ бPAGE2 Fascicle VII.2 Р-Р Rec. U.3 ~еа HH ааЬџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџHpи P Ј XА`ИhР!(#џџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџЬаа X  аУ Уб cмˆ4 PŽТ бRecommendation U.3 Ср8AСб cмˆ4 PŽТ бARRANGEMENTS IN SWITCHING EQUIPMENT Ср8:СTO MINIMIZE THE EFFECTS OF FALSE CALLING SIGNALSФ Ф Ср8;СУУб cмˆ4 PŽТ б(former CCIT Recommendation E.3, Geneva, 1956)ФФ аЬџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџHјP Ј XА`ИhР!(#џџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџЬаТа ТThe CCITT,ЦЦ аЬџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџHpи P Ј XА`ИhР!(#џџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџџЬаУУconsidering а H аФФС С(a)СpСthat transmission systems at present in use for international telex trunks are liable to generate false calling signals; С С(b)СpСthat such false calling signals can seize and engage switching equipment, thereby reducing the grade of service. This is of particular importance with systems in which common equipment normally used only to set up calls is seized by false calling signals; а H аС С(c)СpСthat the ill effects of false calling signals can be minimized by delaying the operation of the calling relay at the termination of the international telex trunk circuit; С С(d)СpСthat, however, when direct dial selection is employed over an international trunk line, unless it is a manually selected circuit not а H аpreceded by a stage of automatic selection, there is normally insufficient time available between successive digits to permit the use of slow operating relays; а H аС С(e)СpСthat, nevertheless, Administrations may agree among one another to use digit storage at the outgoing end of the circuit so that the interР-Рtrain pause can be increased to permit the calling relays to be made slow to operate, УУunanimously declares the view а H аФФС С(1)СpСthat the design and maintenance of transmission systems should be such as to reduce to a minimum the number and duration of false calling signals. In this connection attention is drawn to the merits of frequencyР-Рmodulated voiceР-Рfrequency telegraph systems, particularly with long overhead lines; С С(2)СpСthat, wherever possible, calling relaysй;€ calling relaysб cмˆ4 PŽТ б;й on international telex trunk circuits should have an operation lag of at least 100 milliseconds. Administrations using circuits on lines prone to longР-Рduration false calling signals may agree to use calling relays with longer operation lags.