The term “baseband” has several meanings depending on the context:
1. Communication Technology: In telecommunications, “baseband” refers to a transmission scheme where digital or analog data is sent over a communication channel without modulation. In other words, the data is directly transmitted as-is without any modulation onto the transmission medium. This contrasts with “broadband” transmission, where multiple signals are modulated onto different carrier frequencies.
2. Networking: In networking, particularly in the context of Ethernet, “baseband” refers to a transmission method where signals are sent using digital signaling over a single channel. This is in contrast to broadband Ethernet, where signals are modulated onto multiple channels using Frequency Division Multiplexing (FDM).
3. Signal Processing: In signal processing, “baseband” typically refers to the range of frequencies occupied by the original signal before modulation. For example, in audio processing, the baseband signal would be the audible frequencies, while in radio communications, the baseband signal might refer to the range of frequencies used to transmit digital data before modulation onto a carrier wave.
In all cases, “baseband” essentially refers to the original form of the signal before modulation or processing for transmission.