The modulation used by a dial-up modem is very different from that used by a cable modem, because a twisted-pair phone line and a coaxial cable differ in the amplitude, frequency and phase of the signals they can carry.
The modulation used by a dial-up modem is very different from that used by a cable modem, because a twisted-pair phone line and a coaxial cable differ in the amplitude, frequency and phase of the signals they can carry.
拨接数据机所使用的调制，与缆线数据机大相迳庭，因为电话的双绞线与同轴电缆所携带的讯号，各具有不同的振幅、频率与相位。