Hi Marcus,
Thannks.
Spectrum density , that I have taken was in the are that there were no transmission.
I have RF meter that to measure RF power , HackRF also detected unknown RF that covered by Wi-Fi.
You can see while recording it. RF meter which I have also indicates the radio sound is really unique.
Another product, AirMagnet 2.4 GHz spectrum analyzer shows the same things.
Waterfall Pattern also dfferent. Many people not sure about 2.4 GHz.
in 84 pages document, I have checked all details .
Is there anything that we can extract the information from the signal ( we dont know the protocol ) ?
Regards
Srinivasan T
From: address@hidden [mailto:address@hidden On Behalf Of Marcus Müller
Sent: Wednesday, 10 February 2016 10:29 PM
To: address@hidden
Subject: Re: [Discuss-gnuradio] Re : Info on 2.4 GHz
Hi Srinivasan,
The gr-fosphor plot looks really OK. Why are you surprised that theres spectrum usage on the 2.4GHz ISM band? Remember, that's the band where everyone with a certified device can operate without asking for a license.
Your frequency line plot might indicate you're seeing overflows, which would mean that your PC is too slow to keep up with processing the real time samples that come in. It's really impossible to tell without knowing wheter you saw overflow indicators on your console.
I don't really agree to your dBm measurements. The numbers you see on these plots are not dBm , but dBFS, i.e. just the relation of signal magnitude to 1. That's not direct display of powers.
Best regards,
Marcus
On 02/09/2016 11:47 AM, Srinivasan T wrote:
any info ?
From: Srinivasan T [mailto:address@hidden]
Sent: Saturday, 6 February 2016 12:59 PM
To: 'address@hidden'
Subject: Re : Info on 2.4 GHz
Importance: High
Hi All
I am Srinivasan living in Singapore and have M.Sc. Comp.Sci.
My self and few engineers have detected unknown RF at 2.4 GHz which has different FFT pattern, waterfall image, Radio Sound.
The identification and classification of the signal is really difficult process.
Below is the video reference :
· FFT at 2.4 GHz ( we can see sudden fluctuation and power in db is really high )
Detail : On this video, we can see peak hold in green color that leave a trace something comes and go. Peak Hold line in green color shows external signal interfered at 2.4 GHz
The fluctuation looks like external RF writing to it.
· Spectrum Density of RF at 2.4 GHz
Details : I have taken this video at place where there was no devices that operate at 2.4 GHz ( near plantations ).
We can see noise floor in blue color comes and go.
This external interference cause Wi-Fi at 2.4 GHz to fluctuate and sudden fluctuate at different power level will increase of SNR of Wi-Fi ( signal to noise ratio )
· AirMagnet XT
Details : This software one of the best software available in the market for detection interference Wi-Fi at 2.4 GHz with different options.
We can see FFT picture at real time in leave suddenly max hold around -10 dBm.
· Wi-Fi Fluctuations at Siloam Hospital in Medan - Indonesia
I reported this issue to :
1. iDA - Singapore ( Radio Spectrum monitor - Goverment agency )
2. MCMC - Singapore ( Radio Spectrum monitor - Goverment agency )
3. Balmon - Indonesia ( Radio Spectrum monitor - Goverment agency )
4. Flight Operator because this unknown signal works on the flight as well.
They are not sure on how to pin point the source and other mechanism.
This signal works in 3 countries : Indonesia, Malaysia and Singapore.
The source may come from Satellite and possibility from SES-7 because this satellite has S-band transponder.
Based on my detection :
1. The RF covered by Wi-Fi signal. This can be seen while recording the signal in wav format using SDR# and HackRF
Image below :
2. The carrier frequency is 2.4 GHz
3. Density value which I recorded :
1. 0.4187 mW / m2 ( 418.7 µW / m2 )
2. 0.5520 mW / m2 ( 552.0 µW / m2 )
3. 15.92 mW / m2 ( 15920 µW / m2 )
4. Recently i detected 1827 mW / m2 = 1.827 W / m2 = 1827000 uW / m2
Attached Radio Sound file :
https://mega.nz/#!8thAzY5D!4ZfOmHLSttQKtYQQlz6BBVtV_vqjrVsxSRiJVzdnRqs
Attached technical analysis in 84 pages ;
https://mega.nz/#!YwplVCCT!Acbe00paHk3dLJuf04B5zSBifSw0-bHz5IciiNLgQwY
I know that Radio Sound that can be analyst further.
I am looking for external expert - urgently to help on this. Looking forward for your reply.
Regards
Srinivasan T
HP : 65 - 91236851
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