A design of ADSL central-office access system over ATM is presented. The functions and operation principle of this system are described, and the ATU-C (ADSL Transmission Unit-Central) circuit is also completely analyzed in this paper.是什么意思_A design of ADSL central-office access system over ATM is presented. The functions and operation principle of this system are described, and the ATU-C (ADSL Transmission Unit-Central) circuit is also completely analyzed in this paper.在线翻译_英语_读音_用法_例句