Programmable Broadband Signal Source

The operation of transmitters designed to jam or block wireless communications is a violation of the Communications Act of 1934, as amended ("Act"). See 47 U.S.C. Sections 301, 302a, 333. The Act prohibits any person from willfully or maliciously interfering with the radio communications of any station licensed or authorized under the Act or operated by the U.S. government. 47 U.S.C. Section 333. The manufacture, importation, sale or offer for sale, including advertising, of devices designed to block or jam wireless transmissions is prohibited. 47 U.S.C. Section 302a(b). Parties in violation of these provisions may be subject to the penalties set out in 47 U.S.C. Sections 501-510. Fines for a first offense can range as high as $11,000 for each violation or imprisonment for up to one year, and the device used may also be seized and forfeited to the U.S. government.

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tetan
 
Posts: 4
Joined: Tue Feb 13, 2007 3:11 am

Programmable Broadband Signal Source

Post by tetan »

Hey Ladyada,

Nice project. But it seems to me that you “slightly” overcomplicated an originally simple idea of jammer. Yes, it is nice to have such universal programmable broadband source but you do not want to limit its use only to jamming. In such a case you device has to have a programmable Fmax/Fmin as well as a sweep time, delay between sweeps, frequency hopping, total number of sweeps, device timer on/off, ability co connect external source of modulating signal, external interface that will allow connection of industrial receiver (See: www.nova-eng.com/Inside.asp?n=Products&p=Novasource). Such features can make your Bubble in to industry recognized product that can be used for testing/calibration of professional receivers or just a source of RF signal.

On the other hand, if the main purpose for your device is RF jamming of KNOWN signals, why don’t limit it to a plain SAW+Noise-->VCO-->BandPass filter (widely available for all GSM/CDMA bands)-->Amp-->Antenna. Yes, one needs one set of VCO, Filter, Amp and Antenna for each band but overall cost and simplicity of design is obvious, isn’t it? After all it makes totally scalable system were one can decide what band has to be blocked and technically can be expended to cover up all known GSM/CDMA bands. Nevertheless, it is nice to have an ability to connect external source. It is believed that more than 90% of success in jamming corresponds to initial noise source and it was never about just overwhelming output power. Principles of correlation in signals detection can be applied for their destruction too. It is just something to think about. ;-)

Anyway, as I’ve said before it is VERY nice project. But it is not really a jammer. It is a Programmable Broadband Signal Source. Change the name, lower output power (keep Uncle Sam happy and follow FCC regulations. It can be always left up to end-user to add extra RF power amp) and sell as many kits as you wish. :)

All the best,

Ted

adafruit
 
Posts: 12151
Joined: Thu Apr 06, 2006 4:21 pm

Re: Programmable Broadband Signal Source

Post by adafruit »

tetan wrote:
Nice project. But it seems to me that you “slightly” overcomplicated an originally simple idea of jammer. Yes, it is nice to have such universal programmable broadband source but you do not want to limit its use only to jamming. In such a case you device has to have a programmable Fmax/Fmin as well as a sweep time, delay between sweeps, frequency hopping, total number of sweeps, device timer on/off, ability co connect external source of modulating signal, external interface that will allow connection of industrial receiver (See: www.nova-eng.com/Inside.asp?n=Products&p=Novasource). Such features can make your Bubble in to industry recognized product that can be used for testing/calibration of professional receivers or just a source of RF signal.
only slightly? i think its complete overkill! :) however, this was because i was interested in making a 'end all and be all' of pocket-scale jammers
i also wanted to experiment with PLLs for auto-tuning because many people dont have spectrum analyzers. once you go with a PLL, you start to have to go with all sorts of digital tuning stuff which i did with PWM/digipots
im also an engineers. i overengineer things.
On the other hand, if the main purpose for your device is RF jamming of KNOWN signals, why don’t limit it to a plain SAW+Noise-->VCO-->BandPass filter (widely available for all GSM/CDMA bands)-->Amp-->Antenna. Yes, one needs one set of VCO, Filter, Amp and Antenna for each band but overall cost and simplicity of design is obvious, isn’t it? After all it makes totally scalable system were one can decide what band has to be blocked and technically can be expended to cover up all known GSM/CDMA bands. Nevertheless, it is nice to have an ability to connect external source.
the reason not to go with a bandpass: because you want to jam different bands with one device. if you want simplicity, sure, but there are many simple designs out there already.
It is believed that more than 90% of success in jamming corresponds to initial noise source and it was never about just overwhelming output power. Principles of correlation in signals detection can be applied for their destruction too. It is just something to think about. ;-)
is that actually true? usually with a jammer i find it has to stay on for a while before the signal dies.
Anyway, as I’ve said before it is VERY nice project. But it is not really a jammer. It is a Programmable Broadband Signal Source. Change the name, lower output power (keep Uncle Sam happy and follow FCC regulations. It can be always left up to end-user to add extra RF power amp) and sell as many kits as you wish. :)
im looking forward to seeing you at my appeal!

tetan
 
Posts: 4
Joined: Tue Feb 13, 2007 3:11 am

Post by tetan »

only slightly? i think its complete overkill! Smile however, this was because i was interested in making a 'end all and be all' of pocket-scale jammers
i also wanted to experiment with PLLs for auto-tuning because many people dont have spectrum analyzers. once you go with a PLL, you start to have to go with all sorts of digital tuning stuff which i did with PWM/digipots
im also an engineers. i overengineer things.
I do have a huge respect for you and that is why I've said "slight" :). The girl like you have to be respected for a several reasons: first of all you were not lazy to learn the law, give it a thought and not to get scared. Second, you are the type of the person that not only talks the talk but actually put things together and make them work. Keep it up and you will never have problems with making +100k paycheck.
the reason not to go with a bandpass: because you want to jam different bands with one device. if you want simplicity, sure, but there are many simple designs out there already.
From what I understand, your device can jam only one band at the time anyway. For example, if you were jamming gsm-850 and than decide to go to gsm-1900 you will have to do some action (press button). As you probably know, most of mobile network providers work on a multiple bands and all modern cell phones are capable to automatically switch bands and look for available coverage. Nevertheless, without frequency “hopping” you would not be able provide multiband coverage. “Hopping” feature can be easily implemented just by simple software modification.
is that actually true? usually with a jammer i find it has to stay on for a while before the signal dies.
Ok, let’s categorize jammers. First one is the simple broadband noise generator. All they do – create high intensity electromagnetic field with the certain (Gauss) spectral energy distribution. Sample of such device is a regular unshielded sparkplug. Such devices are extremely ineffective, can be easily defeated and waist tons of energy for nothing. Second category is a noise modulated (or sweeping monochromatic), narrow band RF generators. And that is what you have created. They are just slightly more effective than a first category coz you are at least not wasting energy for whole bunch of frequency but the one that are KNOWN to you and are used by KNOWN receivers. Third, the deadliest category of jammers are not even called jammers. They are known as “spoofers”. What such device does, it transmits signal that goes though Front-End of receiver, unlocks detector and make it do “something” but not to receive true signal. It can only be achieved when you KNOW all about informational signal. Such approach allows successful jamming with only a fraction of RF energy emitted. KNOWING is a key principle of any signal correlation based receiver or jammer.
im looking forward to seeing you at my appeal!
Oooo, common. Hundreds of manufacturers are making RF generators. Look at the link from my original post and try to find any functional difference between what you made and what they made. The only difference is – functional description. You can not sell or market any device that is sold or marketed as jammer. But you will newer have problems selling it as a FR source. HP, Agilent, R&S and many others have no problem selling such devices so why should you have one. There is no law that defines how portable RF source has to be, is there one?
Let me give you another sample. You have no problem marketing knifes for slicing bread but try marketing a same knife for slicing people. Jammers are devices that are prohibited by their definition, not by their function. Just do not call it a jummer. :)

dlwilson
 
Posts: 1
Joined: Wed Feb 14, 2007 11:27 pm

Post by dlwilson »

tetan wrote: [...]
Ok, let’s categorize jammers. First one is the simple broadband noise generator. All they do – create high intensity electromagnetic field with the certain (Gauss) spectral energy distribution. Sample of such device is a regular unshielded sparkplug. Such devices are extremely ineffective, can be easily defeated and waist tons of energy for nothing. Second category is a noise modulated (or sweeping monochromatic), narrow band RF generators. And that is what you have created. They are just slightly more effective than a first category coz you are at least not wasting energy for whole bunch of frequency but the one that are KNOWN to you and are used by KNOWN receivers. Third, the deadliest category of jammers are not even called jammers. They are known as “spoofers”. What such device does, it transmits signal that goes though Front-End of receiver, unlocks detector and make it do “something” but not to receive true signal. It can only be achieved when you KNOW all about informational signal. Such approach allows successful jamming with only a fraction of RF energy emitted. KNOWING is a key principle of any signal correlation based receiver or jammer.
[...]
I hate to use analogy, but it sounds like you're talking about analog versus digital jamming. Analog is just drowning out the signal with noise, digital is communicating with the device to be jammed, and confusing or fooling it. I imagine that cell phones must have some communication protocol, and that if your jammer appears to be a legitimate device like a cell tower, that says "hey, listen to me, I have a stronger signal than the tower you are listening to", you can cause the phone to drop the tower and try to connect with your jammer.

Does the Wave Bubble have the ability to act like a cell tower? You can program it to radiate whatever frequency you want; can you somehow modulate that frequency to communicate with a cell phone?

[I'm a software guy, so I can feel myself rapidly getting out of my depth here.]

Dave

hahahehihoha
 
Posts: 37
Joined: Fri Jan 05, 2007 9:54 pm

WB power

Post by hahahehihoha »

The Wave Bubble (WB) is open-source (apply the almighty Lev Manovich 5 principles of New Media here) and virtually distributed across the common internet.

The WB is a do-it-yourself work, a hands-on, learnable and exciting project with practical and critical applications in daily real-life of an ordinary person in many parts of the world.

Compared to what you can easily find online when searching for jammers, the WB is a device to reckon with.

Relatively few people know about the WB.

There is a possibility that next-generation RF parts will cease being available to common folk, phone manufacturers will adopt new technical strategies to overcome jammers.

The natural electromagnetic spectrum will continue being abused as long as we think at the 100K speeds of engineering. While ironically the WB is a noise transmitter at higher power than the cell phone and when activated it is a provocative behaviour for the average person who has no knowledge of the workings of electronic devices.

Perhaps the most important statement the WB makes is that radio is a man-made synthetic invention built on understanding of natural laws which are readily available and within grasp for everyone.

tetan
 
Posts: 4
Joined: Tue Feb 13, 2007 3:11 am

Post by tetan »

Perhaps the most important statement the WB makes is that radio is a man-made synthetic invention built on understanding of natural laws which are readily available and within grasp for everyone.
That is exactly my point. Look what is happening to us. We are not allowed to do this and that, we can not go there ... We are even afraid to make a broadband source for our own use. WB is a toy with huge political statement and i hope to see this internet project live and kicking many years from now.

When it come to overcoming jammers i do not think it will ever happen. Whatever one man can do another can undo or do better. It is an evolution and shall never end. Unless, as you said, RF parts cease to be available to general public.

spyreal
 
Posts: 1
Joined: Tue Apr 03, 2007 3:02 pm

Post by spyreal »

tetan wrote:
Perhaps the most important statement the WB makes is that radio is a man-made synthetic invention built on understanding of natural laws which are readily available and within grasp for everyone.
That is exactly my point. Look what is happening to us. We are not allowed to do this and that, we can not go there ... We are even afraid to make a broadband source for our own use. WB is a toy with huge political statement and i hope to see this internet project live and kicking many years from now.

When it come to overcoming jammers i do not think it will ever happen. Whatever one man can do another can undo or do better. It is an evolution and shall never end. Unless, as you said, RF parts cease to be available to general public.
I HOPE THIS WILL NEVER HAPPEN!!!

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