AP vs Client RSSI

[piotrPaszk]

Hello,

I know that an AP i going always to see a client better. According to Jerome Harry is about 6dBm difference. I have taken the reading from the controller and I struggle to make out what is what, since the values are the other way round. The client see the ap better or I get that wrong. Can you please help me to interpretate the show client details what is,

1. Radio signal strenght indicator

2. Nearby Ap statistics

3. Scan report

--More-- or (q)uit
Number of RA Packets Dropped............... 0
Number of Policy Errors.................... 0
Radio Signal Strength Indicator............ -66 dBm
Signal to Noise Ratio...................... 33 dB
Client RBACL Statistics:
Number of RBACL Allowed Packets............ 0
Number of RBACL Denied Packets............. 0
Client Rate Limiting Statistics:
Number of Data Packets Received............ 0
Number of Data Rx Packets Dropped.......... 0
Number of Data Bytes Received.............. 0
Number of Data Rx Bytes Dropped............ 0
Number of Realtime Packets Received........ 0
Number of Realtime Rx Packets Dropped...... 0
Number of Realtime Bytes Received.......... 0
Number of Realtime Rx Bytes Dropped........ 0
Number of Data Packets Sent................ 0
Number of Data Tx Packets Dropped.......... 0
Number of Data Bytes Sent.................. 0
Number of Data Tx Bytes Dropped............ 0
Number of Realtime Packets Sent............ 0
Number of Realtime Tx Packets Dropped...... 0
Number of Realtime Bytes Sent.............. 0

--More-- or (q)uit
Number of Realtime Tx Bytes Dropped........ 0
Nearby AP Statistics:
bkom-atealab-ap01(slot 0)
antenna0: 9 secs ago..................... -64 dBm
antenna1: 9 secs ago..................... -63 dBm
bkom-atealab-ap01(slot 1)
antenna0: 248 secs ago................... -64 dBm
antenna1: 248 secs ago................... -75 dBm
atealab-test1(slot 1)
antenna0: 72 secs ago.................... -70 dBm
antenna1: 72 secs ago.................... -74 dBm
atealab-test2(slot 1)
antenna0: 248 secs ago................... -89 dBm
antenna1: 248 secs ago................... -96 dBm
Scan Report:
--------------------
BSSID:......................................... f4:cf:e2:40:7f:ff
RSSI:...................................... -68 dBm
ChannelNumber:............................. 36

thank you

[Scott Fella · Accepted solution]

First look at the TX power your AP is using and try to find the TX power of the device you are using.  Also, if the 11k info is being sent by the client, you can see both what the AP hears the client and what the client hears the AP. You can also use utilities so see what the client hears the AP, refresh rate depends on the driver versions.  Then you can compare the data you are collecting to better understand this and your environment. 

[piotrPaszk · Accepted solution]

Hei Scott,

Thanks for info. I am using -11dBm in UNII-1 so I should not be any mismatch. But I am facing a new project with location and I wonder how I can site survey for that siden there is a requirement that a client should be at -75dBm seen from the pespective of  APs.

So I was thinking I could take the reading from the client vs AP and use that difference as reference. According to Jerrome Herry a client is supposed to see an AP 6dBm worse but I do not see that happen in my case. Maybe that happens when Ap is set to max TX. Do you have any tips to lacation based site survey and how I should approach that ?     

[Scott Fella]

I was at his session also:) When you survey, you want to survey for 5GHz, the location is for -75dBm on 2.4GHz, which you will have depending if you have disabled some 2.4GHz radios. Just keep in mind that the AP has some antenna gain in which wireless devices typically might have a zero gain. Focus on the 5GHz when you survey, look for the proper placement especially when roaming, make sure you have enough density of AP's that can handle around 25 clients in a given area. When you survey, you want to survey and stop to review if you have your -65 edge and extend that out to -75 so you can see how the overlap is, then also focus on the 2.4GHz and see how far out -75dBm cell edge is so you can determine where your next few AP's need to be. I typically will survey one AP to see where my cell boundaries are for -65 and -75 on both 5GHz and 2.4GHz, with 2.4GHz being very low TX power and 5GHz set at 6dbi higher than the 2.4GHz.

[piotrPaszk]

Thanks Scott a lot for all the answers :)

I have only last one :)

Can you help me please understand the output from controller I had in my first post and tell me from which perspective those RSSI values are seen

1. Radio signal strenght indicator

2. Nearby Ap statistics

3. Scan report