ITU-T E 130-1993 Choice of the Most Useful and Desirable Supplemtary Telephone Services《最有用的最称心的补充电话业务的选择》.pdf

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)#%#(/)#%G0G0/ solution No. 3 may improve the handling; solution No. 2 bears the same advantages to the user as solution No. 3 and does not require specialsystem features.