What does Digital Code Squelch (DCS) do in a communication system?

Digital Code Squelch (DCS) is a technique used primarily in radio communication systems to filter out unwanted noise and ensure that only signals with a specific digital code are allowed through. It works by requiring that a transmitted signal match the designated digital code before it can be processed or heard by the receiver. This functionality is vital in communication systems where clarity and signal selection are crucial, such as in naval or other military communications.

By implementing DCS, operators can reduce the chances of hearing irrelevant or disruptive signals, as the system will only 'un-squelch' (or open the audio path) when it detects the correct code. This effectively enhances communication efficiency and clarity, making it easier for operators to focus on pertinent communications among potentially many overlapping signals.

The other choices either misrepresent the primary function of DCS or associate it with capabilities that are not within its scope. DCS does not directly enhance data encryption, increase signal range, or facilitate video signal transmission, as those functions are addressed by other technologies and methods.