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Spectrum Sensing HW.

Started by SenSen 5 years ago7 replieslatest reply 5 years ago231 views

I am interested to use an existing hardware to perform a spectrum sensing/monitoring in the frequency range of 2.2-2.6[Ghz].

Taking into account that the 802.11ac channels are in the range of 2.4-2.5[Ghz], and the active/passive scanning feature supported by the standard, seems that the WiFi spectrum scanning can be done using home routers and a modified firmware.

Wonder how the ranges 2.2-2.4[Ghz] and 2.5-2.6[Ghz] can be covered as well.

Aware of the fact that SDRs can be used for this purpose, however, the aim of the current study is to find a HW available in rural environment, whether a home router or a base station equipment, which is capable to perform such task.

Any leads are welcomed.

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Reply by motilitoApril 14, 2017

You can either use the AD9361 evaluation from Analog Devices, covers frequencies from a few hundreds MHz to 6GHz, with one of the suggested FPGA boards or the LMS6002D from Lime Microsystems, covers frequencies from a few hundreds MHz to 3.5GHz, which works with a low cost FPGA board.

I found the Analog Devices much more documented and you can write your own Linux software for an ARM could on the Zynq FPGA. The only problem is that this option is more expensive.

Good luck

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Reply by SenSenApril 17, 2017

Thank you - Motilito, Fred Marshall and Cogwsn for the detailed and fast reply.

The proposed SDRs(LMS6002D/AD-FMCOMMS2/Ettus) are all good platforms indeed.

As a matter of fact, I am currently using the Ettus Usrp n210 for the research and algorithms evaluation, and find it as a very user friendly kit.

However, the purpose of the current study is to find a network of an existing and already installed Hardware such as Home Routers or Base Station equipment, which will be used as the spectrum sensing nodes, while the searched for RF emitters will be detected by the centralized host. The following figure demonstrates the concept.

network_13923.gif

As the system will incorporate a large number of sensors, the usage of SDR is not being considered.

As a result, I am currently searching for devices with spectrum sensing capabilities and accesable firmware/SW in the range of 2.2–2.6 GHz.

Thanks.

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Reply by Fred MarshallApril 14, 2017

There's a whole range of capabilities:

- PC-based software that shows a "cartoon" of the WiFi spectrum.  It's not really a spectrum analyzer but shows a plot "as if".  For these you'll notice that the spectra are generally shaped the same: like a round mountain or like a trapezoid.  They show a bandwidth that's based on knowing the settings / mode and a signal strength that's actually relative.  I like inSSIDer which can be obtained in a free version from places like majorgeeks.  Not really what you asked for but...

- PC-based spectrum analyzers that come in the form of a USB stick.  Spec's vary.  You may find one that will do what you need.  At least this gives you a receiver and some may use / provide the SDR software.  I'd not be surprised.

Either way, you're going to need a receiver.  So maybe one could tweak an existing WiFi dual-band router.  Way beyond what I know how to do in the details.

Here's a link: http://www.rtl-sdr.com/rtl-sdr-wide-spectrum-analy...

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Reply by SenSenApril 17, 2017

Hello Fred.

Thank you for the reply.

Please see the answer to Motilito.

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Reply by cogwsnApril 14, 2017

I would append to motilito's reply by saying that : if you want to go with AD9361 , USRP B210 from Ettus Research is the best option you can have. 

It will not only monitor your desired range but also 70 MHz till 6 GHz. 

Additionally if you want to go with LMS6002D, bladeRF is the best one, but this is something on which I never worked on. 

For Ettus product, all the software for spectrum sensing is already available :) 

You can see a very old screencast made my me for spectrum sensing which used Ettus USRP-2 

https://www.youtube.com/playlist?list=PLE17083563E...

Hope this helps ! 

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Reply by SenSenApril 17, 2017

Hello Cogwsn.

Thank you for the reply.

Please see the answer to Motilito.

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Reply by SenSenApril 22, 2017

Following a further research, it does not seem to be possible to perform the sensing in the required range using wifi routers only, due to their limited bandwidth. 

As a result, Base Station manufacturers were reviewed according to the listed below: 

rfwireless-world.com/Vendors/… 

As their equipment supports LTE, GSM, UMTS, CDMA etc, standards, and according to the bands information provided at: 

niviuk.free.fr/umts_band.php 

it seems, that the base station equipment, theoretically, can sense the required frequencies 2.2-2.6Ghz.

The 2.4-2.5Ghz band, however, remains uncovered. 

dropbox.com/s/kmfznrfq6pu971o/Bands.png?dl=0

As a result, I wonder whether the existing routers support spectrum sensing in the 2.4-2.5Ghz band.