I have discovered that the Sentinels, and possibly even the Guardian race in general may be communicating using
4B3T (4 binary, 3 ternary) encoding.
Note that I am not in any way an expert on these subjects, so any clarification or input is important here.
For some context:
Barker code is a way of assisting a signal receiver to synchronize the pattern of incoming digits to be regenerated into a message. Barker codes are used in a multitude of communications technologies - GPS, mobile data, and Wi-Fi.
These technologies use
DSSS (Direct-sequence spread spectrum) to mitigate against signal interference and maintain data quality. With DSSS, the message symbols are modulated by a sequence of complex values known as spreading sequence. Each element of the spreading sequence, a so-called
chip, has a shorter duration than the original message symbols. The modulation of the message symbols scrambles and spreads the signal in the spectrum, and thereby results in a bandwidth of the spreading sequence. The smaller the chip duration, the larger the bandwidth of the resulting DSSS signal; more bandwidth multiplexed to the message signal results in better resistance against narrowband interference.
4B3T is a scheme used for ISDN interfaces (Integrated Services Digital Network) - so at this point we could be dealing with an advanced alien internet and telephony service. The Guardians have REALLY good wifi access.
Naturally these are lower quality audio versions, so a clean, high quality FLAC would probably help get the best results.
The Sentinal signal you see here is between 12kHz and 20kHz and consists of two bands with bandwidths of approx. 3-4kHz each. The lower has the clear chip sequence divisions, and the upper band appears to be like a sanity check to validate which ternary code it is (see the table above).
Sentinal Signal Bands:
Lower Primary Band: 12.5kHz-15.5kHz
Upper Sanity Check Band: 17kHz-20kHz
The lower band has chips of 0.02 second intervals.
Spectrogram settings.
Zooming in on the individual chips, you can see a familiar resonance with the Guardian Beacons signal spectra.
Below is when the Sentinel 'squawks' - either as a data output, or the noise is overblowing the embedded data. Also note the chips even have half-chips, there is so much data being spat out!
EDIT: I found out this is likely 'jitter' due to imperfect transmission and is related to clock recovery and the process of 'bit stuffing' to avoid long phases of identical symbols.
Here is an idle Guardian Beacon audio recording. Note the resonance-like waves through the audio as mentioned above.
Zooming in on the dashed pattern, you can see the distinctive chip lines marking the segments of data.
Zooming even further you can see the familiar resonance pattern coming from these distinct data bits. Notice how the data 'blocks' sit at varying horizontal levels, a bit like a punch card reader.
Guardian Beacon Data:
Upper Dashes Bandwidth: 500Hz between 15.5Khz-16kHz
Lower 'Boundary' Line (possibly a pilot signal?): 7.747kHz
The dashes seem to have chips of around 0.012 seconds.
So it looks like the Guardian Beacons act like relay stations to send large packets of locally accumulated data.
I have no idea how to churn through hours of these recordings to decode this stuff. I'm only posting this so someone more technically minded can actually attempt to process the data that is being transmitted by the Guardian features, if it is even decodable at all.
ADDITIONALLY:
Considering what the sentinals and beacons are doing, It is entirely possible that the Guardian Sites are constructed like giant
amplifier circuits. This would explain the unusual markings all over the surface. I also hope this goes some way to solving the mystery of the obelisk glyphs.
Acknowledgements:
Ericlas , Clanga and Maligno for their hard work all those years ago. Sadly some of the published recordings are no longer accessible from their Google links so I had to turn to other sources I could find.
Credit to Commander
@Gadnok (Breaker of Worlds on YT) and for that matter everyone else who has been diligently recording and sharing their findings for the community. I haven't had the ability to immediately jump into the game lately to investigate my ideas so these online recordings have been invaluable. My analysis here is based on this recording he made
Source: https://youtu.be/4YKEA0Q6-NU?si=SsbcVMSJfhXvD2Hp&t=176
Similarly one from Eeka_Droid
Source: https://www.youtube.com/watch?v=lHOTheWpks8
As the Federation said recently about the Shamash event:
It’s easy to think we have the galaxy all figured out, but sometimes… sometimes I wonder just how much of it is beyond our perception.