A device that modulates and demodulates signals for data transmission over telephone lines?

A device that modulates and demodulates signals for data transmission over telephone lines?

• A. Router
• B. 2.4GHz
• C. Modem
• D. Access Point

Answer: (C)

Modulation and demodulation of signals for data transmission over telephone lines is the function of a modem. A modem converts digital data from a device into analog signals that can travel over traditional copper telephone lines, and at the other end it converts those analog signals back into digital data. That capability is what enables data communication over PSTN dial-up and many DSL setups. A router, by contrast, focuses on directing data packets between networks and may share an internet connection, but it doesn’t inherently modulate signals onto telephone lines. An access point provides wireless connectivity to clients, not modulation of telephone-line signals. The reference to a frequency like 2.4 GHz points to a radio band used by wireless networks, not a device that handles modulation/demodulation.

Modulation and demodulation of signals for data transmission over telephone lines is the function of a modem. A modem converts digital data from a device into analog signals that can travel over traditional copper telephone lines, and at the other end it converts those analog signals back into digital data. That capability is what enables data communication over PSTN dial-up and many DSL setups.

A router, by contrast, focuses on directing data packets between networks and may share an internet connection, but it doesn’t inherently modulate signals onto telephone lines. An access point provides wireless connectivity to clients, not modulation of telephone-line signals. The reference to a frequency like 2.4 GHz points to a radio band used by wireless networks, not a device that handles modulation/demodulation.