In communication models, communication takes place between senders and receivers. While the sender prepares the messages generated in terms of transmission technology - coding, modulation, compression, possibly encryption - and transmits them via the transmission medium, the receiver has the task of decoding, decompression, demodulation and decoding.
After decoding, decompression, demodulation and decoding, the signals processed by the receiver are available on the receiving side in the same form as they were processed on the transmitting side. The receiver principle is independent of the transmission technology and applies equally to wireline, optical and radio transmission. The communication model shown applies equally to the various signals such as voice, audio, video and data that have been processed for transmission and reception.