ITU-T E 181-1993 Customer Recognition of Foreign Tones《对外信令音的用户识别》.pdf

1、INTERNATIONAL TELECOMMUNICATION UNION)45G134 % TELECOMMUNICATIONSTANDARDIZATION SECTOROF ITU4%,%0(/.%G0G0.%47/2+G0G0!.$G0G0)3$./0%2!4)/. G0G0.5-“%2). G0G02/54).!.$G0G0-/“),%G0G03%26)#%#534/-%2G0G02%#/.)4)/.G0G0/2) indicate that in some countries the ringing tone may be heard as a sequence of two sho

2、rt tones, pause, twomore short tones, pause, and so on.In addition, it may be useful for the purpose of educating subscribers: to provide auditory samples of such tones by tape recording or other means, or to include detailed descriptions of tones in directories.2 Modern international signalling sys

3、tems are capable of exchanging signals corresponding to indicationsnormally given to subscribers by means of audible tones (busy, congestion, ringing, etc.). Administrations areencouraged to arrange their networks so that these information signals can be sent between countries in order that theycan

4、be recognized and converted into tones or announcements as near to the calling subscriber as practical. Thisprocedure could significantly reduce the language problems arising from the growing use of recorded announcements.Note This Recommendation is complementary to Recommendation E.180 on the stand

5、ardization of tones inthe international telephone network. Whilst standardization is of primary importance, telephone users need informationto assist them in recognizing foreign tones until such time as standardization is complete.This is the purpose of 1 of the present Recommendation which, as exte

6、nsive human factor experiments show,should greatly reduce subscriber confusion.The measure mentioned in 2 does not eliminate the need for tone standardization as well, but can reducecustomer difficulties in cases where standardization may be impractical for a long period but sophisticated exchangesarrangements are available.