Which device is responsible for converting digital signals into analog for transmission through a modulation process?

The device that is responsible for converting digital signals into analog signals for transmission through a modulation process is indeed the modulator. Modulation is a technique used to prepare digital data for transmission over analog channels, such as radio waves or traditional telephone lines. In this process, the modulator takes the discrete digital signals and modifies a carrier wave in such a way as to encode the data onto the wave, allowing it to be transmitted over distances and through various mediums.

Each of the other devices serves different functions within a telecommunications network. For example, a demodulator performs the inverse operation by taking the modulated analog signal and converting it back into a digital format for the receiving end. A repeater's role is to regenerate and amplify signals to extend the distance over which they can travel effectively without degradation. A router, on the other hand, manages data traffic between different networks by determining the best path for data packets but does not engage in the modulation/demodulation processes.

Understanding modulation and the role of modulators is essential for comprehending how digital communication systems operate, especially in contexts where digital data needs to be transmitted over traditional analog infrastructure.