slow signal strength fluctuation and up/down client link

[v.bakirov]

I have completed installation and configuration system which consist WLC5508(HA),MSE and WCS (all soft are last version). APs - 1252 a/b/g/n. But have problem, some clients have a slow signal strength fluctuation and up/down client link per 1hour or 30minuts. I see that this occur, when client change AP, but I can't understand why because client are not roam, they on the one point during all time (laptop on the table for test).

[Leo Laohoo]

Does this happen to the a or b radio?

[v.bakirov]

this test is g (b radio - 2,4).

[Leo Laohoo]

this test is g (b radio - 2,4).

Do you get the same issue with 802.11a?

[v.bakirov]

users with iPAD (802.11a) have lost of connectivity (not often) but I can't find that issue in WCS logs. I see this issue only on 802.11g (or g/n - when n was off problem not fixed).

I have one idea, possibly the same problem like https://supportforums.cisco.com/message/1268182#1268182  but not sure.

[Kayle Miller]

Signal strength measurement is not an industry standard measurement, although dB and mw conversions are a defined standard in the aspect that 100mw is always 20dB not every client card software defines an RSSI of -67dB to be excellent.

So the validation of signal strength can vary widely in the client card software between brands and even between models, or between software releases. So there are a number of factors that play into this also keep in mind that each client cards driver software has it's own roaming behavior, that varies as widely as its depiction of the signal strength values.

Additionaly power save functions and the antenna type in the device can all affect the perceived signal strength and roaming behavior.

So the flux your seeing could be a result of the any of the following items or something else

network design: meaning possibly there is insufficent coverage and the flux you are seeing is actually multipath. 

Client Card: Some client cards just don't perform well and have sub-standard components that impact performance

Driver Software: some driver software is just bad, it has poor algorithims, poor logic, etc.

Bad antenna: the antenna in the device could be of poor quality or defective.

Hope this helps...

Please rate helpful posts.

[George Stefanick]

+5 Kayle

Ill piggy back off this as well..

To test this get a client with a decent supplicant like Intel. Sit monitor and compare what WCS and the supplicant are reporting. Also, KEEP IN MIND. What you are seeing in WCS is how WELL the controller / access point hears your client. So the readings you hear on the client dB wise can be different from from WCS is showing.

[v.bakirov]

I have use intel on my laptop when test on customer network - it was ok! So,  D-link wi-fi network work better with iPAD then Cisco wi-fi network? I don't think so...

[George Stefanick]

If you are looking just at signal strength. You need to also consider the TX power of each access point and antenna gain. Is the Dlink TX at a higher tranmist power and does it have a higher gain antenna than the cisco AP?

[v.bakirov]

I have understand that, but I have situation:

Customer has old wi-fi network and in that network problem  not occur (in old network uses d-link stand alone APs ). And in new network, customer sees this problem. I can't explain this situation like you.