What term describes the complete range of radio frequencies used for communication?

The term "spectrum" is commonly used to refer to the complete range of radio frequencies used for communication. In communications, the electromagnetic spectrum encompasses all frequencies of electromagnetic radiation, including the radio frequencies that are critical for transmitting signals across various forms of communication such as broadcasting, telecommunications, and data communication.

Understanding the spectrum is fundamental for effective communication as it identifies the various frequency bands assigned for different uses, including public safety communications like fire service operations. Each portion of the spectrum is designated for specific types of communication to avoid interference and ensure efficient operation.

The other terms, while related to aspects of communication, do not encompass the full range of radio frequencies in the same way. "Frequency range" refers more generally to any specified set of frequencies, "bandwidth" describes the width of a frequency band allotted for a particular purpose, and "signal range" typically relates more to distance and coverage of a communication signal rather than the spectrum itself. Therefore, "spectrum" is the most precise and appropriate term for describing the entirety of radio frequencies used for communication.