ADSL is a branch of DSL technology, but also the use of ordinary telephone lines to transmit data, but it is used in high frequencyband than the voice.
ADSL是DSL技术的一个分支，同样也是使用普通电话线路来传输数据，但它使用的频率要比语音波段高。
2
Advertisers electronically vary voice sounds so that they stay within such a frequencyband.