OK, this is difficult to explain and difficult to understand. A bit of handwaving and a chalk board is usually required.

The ISM band of frequencies at 2.4 GHz has 80 frequency slots. Each of these slots is 1 MHz wide. This radio set selects two of these 1 MHz slots to operate on.

The global unique ID (GUID) has over 4.2 billion unique codes that are used to spread the energy in each of the 1 MHz frequency slots clustered around 2.4 GHz. The GUID code must be a digital word that is 32 bits long (2 to the 32nd power). It is this code that provides the pseudo-random function that spreads the bandwidth of a low bandwidth control information over a broadband channel. In essence, it takes the information and increases the spectrum bandwidth by a factor of 100. At the same time the signal energy drops by the same factor (in RF terms, this would drop the effective transmitter energy by 20 dB at any frequency in the band) So the signal would appear to just fall away and drop into the noise floor (the noise floor would appear to be slightly elevated, but totally random looking.)

This digital word is mixed in with the control signals and mixed with each of the carrier frequencies which results in the spreading of the signal over each of the 1 MHz frequency slots. This give a broadband signal (about 10 kHz of information spread over about 1 MHz of bandwidth.)

The receiver is uses the same 32 bit code. If it doesn't match up with what the transmitter is using, it rejects the signal as noise (which in essence it is). It does pull the correct signal out of the noise by auto-correlation when the codes match. Correlation has the effect of compressing the broadband signal to a narrow control signal.

I'm sure there are a few of the finer points that I have missed here. It's been about 20 years since I was working with this stuff.