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Previous discussion: https://news.ycombinator.com/item?id=5824286 https://news.ycombinator.com/item?id=5824286 https://news.ycombinator.com/item?id=4334264 ht

Previous discussion: https://news.ycombinator.com/item?id=5824286 https://news.ycombinator.com/item?id=5824286 https://news.ycombinator.com/item?id=4334264 https://news.ycombinator.com/item?id=4334264 I'm still waiting for someone to make an app that does this -- would it require linking 2 phones?

mirashii 13y ago
From what I recall when I skimmed the original paper, you would need more general hardware than the wifi chipset in a phone. Actually, that this says it uses wifi at all is a bit misleading. It happens to work on the same frequency bands that wifi uses, but their experiments did not actually use wifi hardware at all and actually used USRPs. Getting off the shelf wifi hardware to do the same would require firmware and drivers that allow raw access to the radio signals, which no cards I know of come even close to. Additionally for their experiments they needed at least five antenna, so even if it were going to happen with phones you'd probably need more than just two.
- stephengillie 13y ago
  So it's like how Xbee radios use the Wifi radio frequency range, but use their own protocols and are actually 1-2 MHz off from Wifi? Xbee hardware can be co-opted into Wifi transmission by an Arduino or more powerful processor: https://github.com/cjbearman/xbee-wifi-spi-arduino https://github.com/cjbearman/xbee-wifi-spi-arduino I wonder if Xbee devices would be more suitable to this task.
  - pudquick 13y ago
    Actually that driver is specifically for 802.11 (wifi) XBee modules like these: http://www.digikey.com/product-highlights/us/en/digi-international-xbee-wi-fi/108 http://www.digikey.com/product-highlights/us/en/digi-interna... It does not cause 2.4Ghz 802.15.4 XBee modules to act like a normal wifi (802.11) chipset. Just an FYI.
throwawaykf02 13y ago
Actually, this is similar work but by different people. The links you posted are about work at University of Washington, whereas the OP is work done at MIT.

mirashii 13y ago

From what I recall when I skimmed the original paper, you would need more general hardware than the wifi chipset in a phone. Actually, that this says it uses wifi at all is a bit misleading. It happens to work on the same frequency bands that wifi uses, but their experiments did not actually use wifi hardware at all and actually used USRPs. Getting off the shelf wifi hardware to do the same would require firmware and drivers that allow raw access to the radio signals, which no cards I know of come even close to. Additionally for their experiments they needed at least five antenna, so even if it were going to happen with phones you'd probably need more than just two.

stephengillie 13y ago
So it's like how Xbee radios use the Wifi radio frequency range, but use their own protocols and are actually 1-2 MHz off from Wifi? Xbee hardware can be co-opted into Wifi transmission by an Arduino or more powerful processor: https://github.com/cjbearman/xbee-wifi-spi-arduino https://github.com/cjbearman/xbee-wifi-spi-arduino I wonder if Xbee devices would be more suitable to this task.
- pudquick 13y ago
  Actually that driver is specifically for 802.11 (wifi) XBee modules like these: http://www.digikey.com/product-highlights/us/en/digi-international-xbee-wi-fi/108 http://www.digikey.com/product-highlights/us/en/digi-interna... It does not cause 2.4Ghz 802.15.4 XBee modules to act like a normal wifi (802.11) chipset. Just an FYI.

throwawaykf02 13y ago

Actually, this is similar work but by different people. The links you posted are about work at University of Washington, whereas the OP is work done at MIT.