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I'd like to uniquely identify all wireless devices (phones, tablets, etc) within range. I don't care how far the devices are nor do I need to send them anything. I just want to be able to say: phone ABC was in this zone between 9:00 - 9:30, and 17:00 - 18:00.

I was thinking of sniffing Wifi packets but it seems that some phones avoid sending Probe Request packets, furthermore it's difficult to get Wifi cards into Monitor Mode. I've been unable to find any information on EDGE/3G detection.

I'm trying to do something similar to http://louwrentius.com/blog/2011/04/determining-smartphone-market-share-using-wireless-sniffing/.

The approach must "uniquely identify" the device. Meaning I want to be able to differentiate between the same device entering the zone multiple times versus new devices entering.

The approach must collect "anonymous" data, meaning I don't want to record any information that would allow someone to figure out the owner's identity.

What's the best way to detect the presence of mobile devices?

Community
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Gili
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1 Answers1

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Let's first rule out Bluetooth or GSM/CDMA and focus only on 802.11 communications. First, we are assuming that these devices are on and are set to look for a WiFi connection (actively probing) or that they are connected to another network and therefore there is traffic. Using a tool like airodump-ng or similar in monitor mode, you can pick up all the transmissions. Netstumbler and others that aren't truly in monitor mode may not pick up all WiFi traffic. Note that not all cards can go into monitor mode.

You could look into a wireless intrusion prevention system, which is looking for unauthorized WiFi activity. You could also setup a soft-ap as a honeypot and monitor connection or probes against it.

If a node is not transmitting and is not responding to any type of request broadcast over the network, then they don't exist for this scenario. There is no way to broadcast a magic packet that turns on WiFi unless perhaps the device is a 3G/CDMA data device which when it receives no signal falls back on WiFi.

Gareth
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Eric G
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