"Spectrum" is frequency domain, not time domain or space domain. It is a completely different abstract space. The concept of "US Spectrum" is nonsensical.
A packet does not leave hardware and enter spectrum; that is nonsensical. A packet leaves one space and enters another space.
The spectrum part is already settled in the oscillator inside the hardware.
Control over parts of the spectrum is demarcated by space. For instance, you can transmit in certain bands, but only for a certain range.
Inside an electronic box, all sorts frequencies can occur, as long as they don't escape in excessive amounts.
It's all about space. When two users use the same frequency band in the same space there is a conflict.
A packet does not leave hardware and enter spectrum; that is nonsensical. A packet leaves one space and enters another space.
The spectrum part is already settled in the oscillator inside the hardware.
Control over parts of the spectrum is demarcated by space. For instance, you can transmit in certain bands, but only for a certain range.
Inside an electronic box, all sorts frequencies can occur, as long as they don't escape in excessive amounts.
It's all about space. When two users use the same frequency band in the same space there is a conflict.