1、INTERNATIONAL TELECOMMUNICATION UNION)45G134 (c) that a defined error rate objective should be established;(d) that all forms of current wideband transmission techniques have intrinsic characteristics that make someerrors economically unavoidable;(e) that occasional bursts of errors occur (errors th
2、at are concentrated into a relatively short time interval, i.e.seconds),unanimously declares(1) that the quality of service must be the same for telegraph communication in the public telegram service, thetelex service and the leased circuit service;(2) that the objective, irrespective of transmissio
3、n media and intervening equipment, should be an error rate notgreater than 3 in 100 000 alphabetic telegraph signals transmitted;(3) that the error rate objective should have not less than a 95% probability;(4) that, in the determination of error rate, measurements should be made for relatively long
4、 time periods, i.e.for at least several hours (see Note 1);(5) that the effects of operator error rates (e.g. in the public telegram service) and of local ends and theirterminations (e.g. teleprinters) should be excluded when determining the error rate.Note 1 The minimum time interval should include the busy hour and be of at least 12 hours duration.Note 2 The absolute value for the error rate objective requires further study.Reference1 CCITT Definition: Character error rate, Vol. I, Fascicle I.3 (Terms and Definitions).
