On Mon, 25 Mar 2002, Toni Heinonen wrote: > In the US and Europe, Bluetooth uses frequencies 2.400 MHz to 2.483,5 > MHz, with 79 different bands to hop on, each 80 MHz wide or sometimes > more. Seeing as you would not try to synchronize your jammer with the I suspect you mean 2.4000 GHz to 2.4835 GHz. That's a total of 83.5 Mhz of bandwidth. I fail to see how you can get 79 *different* bands each 80 MHz wide in an 83.5 MHz space. > hop sequence, do you think it would really be capable of jamming that > whole band? After all, even a square wave won't produce that much of a > disturbance to the neighbouring bands. I mean, of course you could Blotting out a signal is always easier than detecting it. Generating 83.5 Mhz of noise at 2.4 GHz isn't hard at all. > build a jammer like that, but wouldn't it cost too much? I mean, I see > your point: Less than $10. > > It will always be cheaper to DoS a wireless network than it > > is to build > > it. > > Of course, the whole idea is that the protective safeguards for a > system do not cost more than the protected assets. Seeing as how a > Bluetooth chip is supposed to cost 5$ (of course not yet, but probably > so after mass production), would it really be possible to build a > jamming device of this magnitude for 10$ (the cost of a two-machine > Bluetooth network)? Would it really be possible to build a Bluetooth network for $10? I'll bet teleware.fi will never bill $10 for building one. While not a law of nature, it has been consistently demonstrated that wireless networks cost more than the vendor claimed and aren't as reliable as the vendor claimed. Bluetooth is the 'latest and greatest' in a long line of solutions that have consistently failed to live up to their claims. Here's a great example; Motorola sold a communications system to my state, making the same claims you make for bluetooth. It carries Police, Fire, EMS and government voice and data traffic. It is used for dispatching, Mobile Data Terminals and control of MOSCAD devices such as traffic lights. It was finished several years late, 200% over budget, and has never achieved more than 95% reliability. Worse, it would cost about $100 to disable this multi-million dollar system. It uses a small number of frequencies in the 800Mhz band for digital frequency hopping. The frequencies are fixed, and the PSN is so weak you can break it in realtime. If you're laughing now, sell a similarly scaled Bluetooth solution. By the time it is deployed, it will in perspective be as laughable as motorola's solution. > Additionally, you did not comment on my analysis of WLAN/UMTS > transmission a la DSSS. Do you have any ideas there? Plenty. Send specs, a prototype and a check.
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