Linux/WL1807MOD: How to get signal strength, bitrates for the AP on Linux

Sameer Patel

Part Number: WL1807MOD

Tool/software: Linux

Hi,

- On the AP, is there a way, on Linux, using a command-line utility or some C API, to get the signal strength to associated clients?

- Are the bitrates and MCS values shown by iw accurate? Is there a better way to get these numbers?

I tried "iw dev <ifname> station dump" and got:

Signal: 0dBm

Tx bitrate: 1.0MBit/s

Rx bitrate: 39.0 MBit/s

Signal: 0 dBm

Signal avg: -119 dBm

The command “iw dev <ifname> link” on the associated client gives:

Tx bitrate: 78.0 MBit/s MCS 12

Rx bitrate: (not shown)

Signal: -40 dBM

Signal avg: (not shown)

On the AP side, the command always shows “0dBM” for the signal and a very low value for “Signal avg,” which can’t be right given that the devices are separated by less than a meter and iperf is showing decent performance. The figures seem reasonable on the client side. Also, the bitrates fluctuate rapidly and rarely match. The Tx bitrate on the client side seems more accurate.

Thanks,

Sameer Patel

Siemens Ruggedcom

over 8 years ago

0 Vihang Parmar over 8 years ago

TI__Mastermind 29291 points

Hi,

Your query has been assigned to a relevant expert. We will get back to you soon.

Best regards,
Vihang

0 Eyal Reizer over 8 years ago in reply to Vihang Parmar

TI__Mastermind 20285 points

you can use hosdtapd_cli "all_sta" command to get the list of connected station.

Then use "iw wlan1 station get <mac_address_of_station>" to get the rssi for each.

For example:

iw wlan1 station get b4:74:43:fa:e8:c9

Station b4:74:43:fa:e8:c9 (on wlan1)

inactive time: 13600 ms

rx bytes: 265032

rx packets: 2701

tx bytes: 49516

tx packets: 433

tx retries: 0

tx failed: 0

signal: 0 dBm

signal avg: -38 dBm

tx bitrate: 1.0 MBit/s

rx bitrate: 65.0 MBit/s MCS 7

authorized: yes

authenticated: yes

preamble: short

WMM/WME: yes

MFP: no

TDLS peer: no

BR,

Eyal

0 Sameer Patel over 8 years ago in reply to Eyal Reizer

Prodigy 40 points

Hi Eyal,

I tried "iw station get" and got similar results. See below. The first time I run this command it shows something reasonable -- -23 dBm. But if iperf is running continuously in the background the signal avg degrades to between -100 dBM and -120 dBM. The results on the client side (also taken with iperf running) look much better: I get between -20 dBm and -25 dBm. I pasted those below the AP output. Also, on the client side, the figure from "iw" matches what I get from wpa_cli scan+wpa_cli scan_results.

Is there any other way to do this?

Thanks,

Sameer

Siemens Ruggedcom

[ station dump on AP]

Station e4:6f:13:2a:3b:b7 (on wla-rx1400-1)
        inactive time: 0 ms
        rx bytes:       486091781
        rx packets:     17589778
        tx bytes:       809437608
        tx packets:     9427779
        tx retries:     0
        tx failed:      100

signal: 0 dBm

signal avg: -115 dBm

        tx bitrate:     1.0 MBit/s
        rx bitrate:     65.0 MBit/s MCS 7
        authorized:     yes
        authenticated: yes
        preamble:       short
        WMM/WME:        yes
        MFP:            no
        TDLS peer:      no

[iw link on client to above AP]

Connected to 8c:8b:83:75:20:f0 (on wlc-alias-1)
        SSID: rx1400-1
        frzmeq: 2427
        RX: 17474162 bytes (203076 packets)
        TX: 617936766 bytes (402982 packets)
        signal: -19 dBm
        tx bitrate: 65.0 MBit/s MCS 7

        bss flags:      short-slot-time
        dtim period:    2
        beacon int:     100

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Linux/WL1807MOD: How to get signal strength, bitrates for the AP on Linux