how see AP radio MIMO output on 9800 WLC

[wg wireless]

hi, 

We have a setup of 9800 WLC with 1562I outdoor APs. Even when standing next to the AP, the signal is weak (like -55dBm) it should be in the range of -35 to -45 when that close to the AP. Also, checked the power levels, both radios are operating on power-1. What I am suspecting is that AP is not getting full power from the power injector and may have switched down MIMO streams. 

Please suggest a way to see if the AP is operating on 3x3 MIMO which is supposed to be. Is there any CLI command on 9800 WLC to see the AP radio MIMO output status?

[marce1000]

 - You may (also) try  to reboot the access point and  immediately after boot connect to it and issue the show logging command , watch for related output(s) , 

 M.

[Leo Laohoo]

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@wg wireless wrote:
the signal is weak (like -55dBm)

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-55 dBm is not "weak".  Not even close.  

[wg wireless]

yeah it is not weak in general but not acceptable when you are literally standing 1 meter away from the AP and AP radios running on full power. The moment you walk like 15 meter away the signal is below -70 dBm. 

[Leo Laohoo]

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@wg wireless wrote:

yeah it is not weak in general but not acceptable when you are literally standing 1 meter away from the AP and AP radios running on full power. The moment you walk like 15 meter away the signal is below -70 dBm. 

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1. How high is the 1562I installed?
2. What is the angle (tilt) of the AP?
3. Was the RSSI measured on the 2.4 Ghz or 5.0 Ghz?
4. What was the Tx power of the AP at the time the RSSI was measured?
5. How is the 1562I powered? 
6. Is the AP operating in Full Power or not?

I have no idea what equipment was used to test the RSSI but a lot of simple wireless NIC have the capabilities to "close your ears" when the RSSI is too strong.  

[wg wireless]

Appreciate your response but my question is very simple. Is there a way to check the MIMO streams AP is operating on? from WLC GUI or CLI?

[Leo Laohoo]

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@wg wireless wrote:
Is there a way to check the MIMO streams AP is operating on?

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That depends if the AP is operating in full power, partial or low power.

[marce1000]

 - Check if these commands could provide the info you need and or are available :
                 show ap name APname config slot 0 | sec 802.11n Antennas
                   show ap name APname config slot 1 | sec 802.11n Antennas

 M.
                 
                       

[Rich R]

And another question: what version of software are you running?

There are a number of bugs for Tx power levels which have been fixed so this is relevant.

Presume you have read the datasheet on powering the AP - particularly the note on using 802.3at power? https://www.cisco.com/c/en/us/products/collateral/wireless/aironet-1560-series/datasheet-c78-737416.html

Powering options

●  AC (with AIR-PWRADPT-RGD1=, AC/DC outdoor power adapter) ●  44–57 VDC input ●  Universal Power of Ethernet (Cisco UPoE+ and Cisco UPoE), 802.3at ●  Cisco power injectors: AIR-PWRINJ-60RGD1= (outdoor rated, 60W, with NEMA 5-15 AC plug) AIR-PWRINJ-60RGD2= (outdoor rated, 60W, unterminated AC cable) AIR-PWRINJ6= (indoor, 802.3at) Note: If 802.3at Power over Ethernet (PoE) is the source of power, the 1562I radios will shift from 3 x 3 to 2 x 2.

[wg wireless]

Thanks for the reply. What you are mentioning regarding software bug affecting Tx levels can be interesting to check. Although the Tx level of both radios is showing power level 1 (max) when we check on WLC.I will check the software version and if any known issues are documented with Tx power. If you can plz share a link pointing to such bugs reported in 9800 regarding Tx levels that would helpful.

[Rich R]

There are many bugs but a very recent one for example (not yet fixed) is https://bst.cloudapps.cisco.com/bugsearch/bug/CSCwa78731
You can search for others yourself in the bug search tool - just search for tx power and Cisco Aironet 1560 Series.  Note the problem is in the AP code not the controller.  Often it's common across multiple APs - sometimes only those with specific chipsets but don't be misled by headings which only mention a single AP type.  Check the notes and affected products.

[Arshad Safrulla]

Hi WG,

As I am aware there is no way you can check this from the WLC itself. Most simple way to check this open the data sheet of the AP model you have (in your case look for the variant in 1562) and then check from the WLC what level of power it is receiving from the POE injector. 

show ap config general | i Cisco AP Name|Power Type/Mode

Then go to the data sheet and compare what's the expected performance for the standard of power AP is delivering.

I am wondering what MIMO has to do with RSSI? I would look at other issues such as WLC configuration issues such as TPC levels assigned for the AP, RRM configuration, channel assignment and TPC restrictions for the channel, AP mounting location and expected coverage pattern etc. I assume that you are using and 1562i since you are talking about 3x3, I will start checking the AP LED if it is changing red,green& amber to off. Also I would suggest that you check this with a specialized tool like ekahu with ap name advertisment enabled so you can identify this easily.