Tónuskódolással

Tónuskódolással, also known as tone coding, is a technique used in telecommunications and audio processing to represent specific information or commands within an audio signal through variations in its tone or pitch. Instead of transmitting data as a series of binary bits, tone coding utilizes modulated audio frequencies to convey these signals.

This method is often employed in situations where a dedicated data channel is not feasible or cost-effective. For instance, older telephone systems might have used tone coding to signal call waiting, busy signals, or to dial numbers. In some radio communication systems, specific tones can be used to identify a transmitter or to trigger certain functions on a receiver.

The process involves encoding data into a sequence of distinct tones, each representing a specific piece of information. The receiver then decodes these tones by analyzing their frequencies and durations. This can be achieved through various modulation techniques, such as frequency-shift keying (FSK), where different frequencies represent different data states.

While modern digital communication systems have largely surpassed tone coding for complex data transmission due to their efficiency and reliability, it remains a relevant technology in specific niche applications and legacy systems. Its simplicity and the ability to transmit signals over audio channels make it a practical solution for certain control and signaling purposes. The distinct sound of these tones is often recognizable by users as a form of audio feedback.