ITU-T R 40-1988 COEXISTENCE IN THE SAME CABLE OF TELEPHONY AND SUPER - TELEPHONE TELEGRAPHY《电话与话上电报在同一电缆内的共存》.pdf

《ITU-T R 40-1988 COEXISTENCE IN THE SAME CABLE OF TELEPHONY AND SUPER - TELEPHONE TELEGRAPHY《电话与话上电报在同一电缆内的共存》.pdf》由会员分享，可在线阅读，更多相关《ITU-T R 40-1988 COEXISTENCE IN THE SAME CABLE OF TELEPHONY AND SUPER - TELEPHONE TELEGRAPHY《电话与话上电报在同一电缆内的共存》.pdf（3页珍藏版）》请在麦多课文档分享上搜索。

1、INTERNATIONAL TELECOMMUNICATION UNION)45G134 2 TELECOMMUNICATIONSTANDARDIZATION SECTOROF ITU4%,%2!0(94%,%2!0(G0G042!.3-)33)/.#/%8)34%.#%G0G0).G0G04(%G0G03!-%G0G0#!“,%/amended at Geneva, 1951 and at Melbourne, 1988)The CCITT,considering(a) that this process provides only one telegraph channel, in add

2、ition to the telephone channel, and that it canbe applied only in comparatively few cases (lightly loaded or unloaded circuits, which cannot be used for multi-channelcarrier telephony);(b) that in such cases, the Administrations and private operating agencies concerned could in most cases bycommon a

3、greement contemplate the possibility of making use of some other more suitable process that would provide,in addition to the audio telephone channel, more than one telegraph channel;unanimously declares the viewthat the use of super-telephone telegraphy (Definition 02.25, Recommendation R.140) should not prejudice thequality of transmission over the adjacent telephone channel and that, in particular, it should not limit the band offrequencies necessary for good speech reproduction (300 to 3400 Hz at least).