Hi all.. Now I'm working on my degree final year project on building intruder system base on WIFI signal, and more precisely using the RSSI. As we all know human body contain water, and water can interrupt radio signal. Previously my friend have successfully prove that, yes there are significant change of the RSSI when human existence in the testing environment. So, I try to improve the project with using mesh wireless router/node so that the RSSI that I get is more accurate and interesting, because if I use wireless mesh product, I can divide it into several wireless mesh. So the prediction model, that I produce will and can detect where the source of the interruption/intruder. Yes, I know there will be so much noise and factor that will give effect on RSSI, like environment humidity, temperature, even some say lightning.. but i think this is an interesting subject to explore.. So my question, is that possible that I can get RSSI between the mesh router involved using the wireshark? Not from my workstation to the access point, like what wifi scanner INSIDER can offer(example). asked 13 Feb '13, 09:41  awi216 |
One Answer:
well, yes. Kind of.... But wouldn't it be much better to use an open source firmware for the APs and then read those (and possibly other interesting values) directly from the hardware? Just a thought. Regards answered 13 Feb '13, 11:10  Kurt Knochner ♦ |
THx for reply..
APs that I use to create the mesh network is open-mesh product-OM2P. The product come with cloudtrax, so that we can monitor the nodes anywhere-have internet access. Example like this picture.
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For the purpose of to build the prediction model, I have to collect data/RSSI values for each node, and between each node, example like every 100ms in about 10 minutes for each point, and about 20 point in controlled environment. So, I need some sort of packet analyzer, that can analyze packet and record the result.
The RSSI value in a capture file (if it is recorded at all by the sniffer hardware), will show the signal strength 'measured' at the antenna of the sniffer device. So, if you want to capture the signal strength (RSSI) for every node (AP), you would have to place a sniffer next to each AP or at least in the middle of each AP pair or at a 'central' location where you see the signal of all APs. That's an impractical approach for a large number of APs and the less sniffer systems you deploy, the less accurate the results will be. Imagine just one sniffer system 'in the middle' of a large room. Yes, it will see all signals, but there are so many things that reduce signal quality that it will be hard to read any meaningful data from the recorded RSSI of all signals. Furthermore, the capturing hardware is usually only able to monitor one channel at once. If some APs change their channel (to improve signal quality) you will miss the signals of those APs.
That's why it is probably better to read those values directly from the wifi hardware of the APs itself. However you need APs that allow access to that kind of data, which is usually only possible with an open (source) firmware (OpenWRT, dd-wrt, etc.).
BTW: Do you know these papers?
Anyway. If you still want to analyze the RSSI values with Wireshark, you need a system that records those (or similar) values.
To sum it up: You need a system that will record the RSSI value (or similar values - radiotap
antenna signalandantenna noise). If that is the case, you can analyze it with Wireshark.Regards
Kurt
THx man.. your answer is really helpful
Good to hear.
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