How to retrieve the WiFi signal strength via HTTP API on IR300?

How to retrieve the WiFi signal strength via HTTP API on IR300?

When you want to retrieve the surrounding AP's signal strength, you could use the command: 
curl -u adm:123456 192.168.2.1:4444/update.cgi -d "exec=wlscan" -H "Content Type:text/plain"
You can see the result as below:

When you want to retrieve the wifi-connected devices' information and signal strength, the command is:
curl -u adm:123456 192.168.2.1:4444/update.cgi -d "exec=stainfo" -H "Content Type:text/plain"
And the corresponding parameters are:

MAC
MODE
AID
BSS
PSM
WMM
MIMOPS
RSSI0/1/2
PhMd
BW
MCS
SGI
STBC
Idle
Rate
46:35:7B:C5:40:19
20001
1
0
1
1
3
-35
HTMIX
20M
7
0
1
270
65
7C:21:4A:CE:25:07
20001
2
0
0
1
1
-34
HTMIX
20M
7
0
1
299
65