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Could WiFi analyzers effectively determine information about space from a single location? Time is obviously possible, but isn't it inherently providing informa

Could WiFi analyzers effectively determine information about space from a single location? Time is obviously possible, but isn't it inherently providing information about space by providing power readings from a single point?

jrockway 10y ago
Which WiFi analyzer actually looks for traffic? Most of the ones I've seen (a popular Android app) just show you beacons. Seeing beacons != seeing traffic.
- voltagex_ 10y ago
  I'm probably wrong but doesn't seeing traffic require monitor mode on whatever chipset? I've never looked into whether the the Nexus 4, 5 or 7 (2013) can do monitor mode but it'd be interesting to find out.
- chrisfosterelli 10y ago
  I never mentioned a WiFi analyzer that can see traffic. By "time is obviously possible" I meant "an obvious improvement that could be made based on your description"
- nitrogen 10y ago
  Ubiquiti Wifi devices I've used have a built-in spectrum analyzer that can show channel, time, and intensity (a rough proxy for distance).
  - wtallis 10y ago
    The hardware capability Ubiquity is probably using: https://wireless.wiki.kernel.org/en/users/drivers/ath9k/spectral_scan https://wireless.wiki.kernel.org/en/users/drivers/ath9k/spec... This is an awesome and useful feature, but it isn't quite the same as monitor mode packet capturing. The FFT won't do much to help you figure out whether the interference is coming from a really high traffic volume or just a talkative 802.11b IoT PoS.
freyir 10y ago
Using the spatial dimension means directing a WiFi signal in a particular direction, or nulling interference in a particular direction. This can be done adaptively using multiple antennas on a single device. There are mainly two techniques. The first, beamforming, involves adjusting the signal phase over each antenna such that it all adds up constructively in some direction. The second spatial technique, called spatial multiplexing, involves transmitting a different signal across each antenna, and hoping that each signal travels along a sufficiently different path (reflecting off walls, etc.) that all the signals can all be sorted out at the receiver.

jrockway 10y ago

Which WiFi analyzer actually looks for traffic? Most of the ones I've seen (a popular Android app) just show you beacons. Seeing beacons != seeing traffic.

voltagex_ 10y ago
I'm probably wrong but doesn't seeing traffic require monitor mode on whatever chipset? I've never looked into whether the the Nexus 4, 5 or 7 (2013) can do monitor mode but it'd be interesting to find out.
chrisfosterelli 10y ago
I never mentioned a WiFi analyzer that can see traffic. By "time is obviously possible" I meant "an obvious improvement that could be made based on your description"
nitrogen 10y ago
Ubiquiti Wifi devices I've used have a built-in spectrum analyzer that can show channel, time, and intensity (a rough proxy for distance).
- wtallis 10y ago
  The hardware capability Ubiquity is probably using: https://wireless.wiki.kernel.org/en/users/drivers/ath9k/spectral_scan https://wireless.wiki.kernel.org/en/users/drivers/ath9k/spec... This is an awesome and useful feature, but it isn't quite the same as monitor mode packet capturing. The FFT won't do much to help you figure out whether the interference is coming from a really high traffic volume or just a talkative 802.11b IoT PoS.

freyir 10y ago

Using the spatial dimension means directing a WiFi signal in a particular direction, or nulling interference in a particular direction. This can be done adaptively using multiple antennas on a single device. There are mainly two techniques. The first, beamforming, involves adjusting the signal phase over each antenna such that it all adds up constructively in some direction. The second spatial technique, called spatial multiplexing, involves transmitting a different signal across each antenna, and hoping that each signal travels along a sufficiently different path (reflecting off walls, etc.) that all the signals can all be sorted out at the receiver.