Constantly showing 10 dbm as rssi

asked 2020-01-18 16:17:46 +0000

Hello.I have a university project in which i have to find the connection between signal strength and distance from the AP.In order to achieve that i tried walking around my house and at the same time checking the RSSI dbm.In some cases the true dbms would be shown but mostly i would get 10 dbm as a result.Could this be because my AP in order to minimize the BER strengthens automatically its signal?I have read that in wlan there is no such thing as automatic signal stregthening but only automatic drop in bit rate.Does anyone has any idea about what could the problem be?Thanks in advance:)

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Shown where? Wireshark or some other tool? Be sure you are looking at frames from the AP, not frames transmitted by your device.

Bob Jones gravatar imageBob Jones ( 2020-01-18 18:27:56 +0000 )edit

Hello.The problem occurs while using wireshark.I have put specific wlan.da display filters so there is no chance that the messages are from my host.An interesting fact is that this problem occured only when i used iperf to measure the download link speed of my host.Normally without perf i would also receieve mesages with 10 dbm in the rssi field,but this would happen less frequently.

li8rini gravatar imageli8rini ( 2020-01-19 16:18:27 +0000 )edit

We need some system details. What are you using for monitor mode? Host OS / wireless chipset? If Linux, kernel version may matter. It would help to share a trace, as well, in a publicly available location.

It's best not to use an adapter in monitor and managed mode at the same time.

Bob Jones gravatar imageBob Jones ( 2020-01-19 21:05:28 +0000 )edit

Hello again.Some info: Pc model:Toshiba Satellite c855-22m Os: ubuntu 18.04.(64) Nic info: Card manufacturer: Liteon Technology Corporation Driver:Realtek Semiconductor RTL8723AE Interface:Virtual interface in monitor mode(I want to capture wlan messages)
Some news:- This problem occured also when i sniffed wlan messages with wireshark,tshark,pyshark and airodump so i am guessing that this problem doesnt have to do with the programs. -I am using iperf in order to determine the bandwidth of my network and i figured out that this problem appears only when i am flooding my host with traffic of over 1Mbps.When the traffic is over 1Mbps the amount of messages which contain 10 db as rssi increase respectively to the traffic.I think that the route of all this evil must be my ancient pc after all:P

li8rini gravatar imageli8rini ( 2020-01-22 23:21:16 +0000 )edit

It's best practice to use a separate wireless adapter in monitor mode to capture traffic; I don't use the same adapter to communicate and sniff as the results are often unusual and driver specific.

Anyway, if you just want to see how the signal drops as move to and from the AP, Wireshark could be used but probably is not the best choice. An app or program that is used for site surveys would probably be easier to use and give you that specific information. For Linux, some CLI tools that can give you this would be airodump-ng or horst. I am sure there are others; for a Macbook, Netspot is effective for this type of thing.

Bob Jones gravatar imageBob Jones ( 2020-01-23 11:39:59 +0000 )edit