Is there any cheaper alternative to survey systems like Ekahau to fill an existing map/drawing with signals or quality levels ?
Can one use a pair of Wifi routerboard to achieve similar goal even thinking to fill manually the map with signal levels ?
Thanks

A simple solution for a rf signal reference.
root@c7_4:~# iperf3 -c 192.168.61.253 -B 192.168.61.201 -R
Connecting to host 192.168.61.253, port 5201
Reverse mode, remote host 192.168.61.253 is sending
[ 5] local 192.168.61.201 port 44991 connected to 192.168.61.253 port 5201
[ ID] Interval Transfer Bitrate
[ 5] 0.00-1.00 sec 17.8 MBytes 149 Mbits/sec
[ 5] 1.00-2.00 sec 22.6 MBytes 189 Mbits/sec
[ 5] 2.00-3.00 sec 36.0 MBytes 302 Mbits/sec
[ 5] 3.00-4.00 sec 34.6 MBytes 290 Mbits/sec
[ 5] 4.00-5.00 sec 35.9 MBytes 300 Mbits/sec
[ 5] 5.00-6.00 sec 37.2 MBytes 314 Mbits/sec
[ 5] 6.00-7.01 sec 37.5 MBytes 313 Mbits/sec
[ 5] 7.01-8.00 sec 36.9 MBytes 310 Mbits/sec
[ 5] 8.00-9.00 sec 36.9 MBytes 310 Mbits/sec
[ 5] 9.00-10.00 sec 36.8 MBytes 309 Mbits/sec
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval Transfer Bitrate Retr
[ 5] 0.00-10.01 sec 335 MBytes 281 Mbits/sec 17 sender
[ 5] 0.00-10.00 sec 332 MBytes 279 Mbits/sec receiver

iperf Done.

root@c7_4:~# iwinfo wlan0 info
wlan0 ESSID: "test"
Access Point: 1C:3B:F3:4F:E4:23
Mode: Client Channel: 40 (5.200 GHz)
Center Channel 1: 42 2: unknown
Tx-Power: 23 dBm Link Quality: 40/70
Signal: -70 dBm Noise: -102 dBm
Bit Rate: 87.8 MBit/s
Encryption: WPA2 PSK (CCMP)
Type: nl80211 HW Mode(s): 802.11nac
Hardware: 168C:003C 0000:0000 [Qualcomm Atheros QCA9880]
TX power offset: none
Frequency offset: none
Supports VAPs: yes PHY name: phy0

root@c7_4:~# cat survey_20240622
TX (MBit/s);RX (MBit/s);Link Quality;Signal (dBm);Noise;Label
1170.0;1300.0;69/70;-41;-100;1
1170.0;1300.0;70/70;-40;-100;2
1170.0;1300.0;70/70;-33;-100;3
975.0;702.0;70/70;-36;-100;4
1170.0;975.0;67/70;-43;-100;5
1300.0;1300.0;66/70;-44;-100;6
975.0;975.0;51/70;-59;-100;7
526.5;526.5;48/70;-62;-100;7.2
526.5;526.5;48/70;-62;-100;8
526.5;526.5;42/70;-68;-100;9
975.0;975.0;51/70;-59;-100;10
975.0;975.0;51/70;-59;-101;11
975.0;975.0;59/70;-51;-101;12
526.5;526.5;36/70;-74;-100;13
351.0;526.5;51/70;-59;-100;14
.......

Good starting point to have at least a dBm list
Thank you

Each row in survey_20240622, in the fourth column is a dBm reading at different points in the office of a client we have surveyed.

The measurement can be related to different devices by comparing the connection values at a selected point. In this way, an approximate field satisfaction can be obtained for different client devices.

5G Channel: 100 (5.500 GHz)

-28 dBm TP-Link Archer C7
-39 dBm OnePlus Nord
-47 dBm Samsung Galaxy S21 Ultra
-52 dBm Samsung Galaxy A13

2.4G Channel: 6 (2.437 GHz)

-31 dBm TP-Link Archer C7
-39 dBm OnePlus Nord
-47 dBm Nokia 3.4


5G Channel: 48 (5.240 GHz)

-32 dBm dBm TP-Link Archer A7
-44 dBm Bogi iPhone 13 Pro max
-46 dBm Georgis iPhone 12, iOS 15.5
-48 dBm OnePlus Nord

2.4G Channel: 11 (2.437 GHz)

-35 dBm dBm TP-Link Archer A7
-42 dBm OnePlus Nord
-48 dBm Bogi iPhone 13 Pro max

This is a sketch of the surveyed office with measurement points marked.

If you have an android phone try analiti it has a coverage analyzer