电信专业英英词典D-7（在线收听）

　　DSU

　　data service unit

　　DTMF

　　dual tone multiple frequency

　　DTS

　　digital termination service

　　Dual-Tone Multiple Frequency (DTMF)

　　the generic name for the tone signaling scheme used to signal from telephones to switching equipment, in which 10 decimal digits and two auxiliary characters are represented by selecting two frequencies of the following group: 697, 770, 852, 941,1209,1336,1447 Hz.