Have you had an issue with the PMP SMs where the Transmit signal is too high to the AP that will not allow the SM to connect? Is there any way to throttle down the transmit power of the SM or do we need to find a lower gain antenna.
These 2 SMs have clear LOS. The problem we were having at first was when it was pointed away we were getting some odd modulation levels, anything form 8x to MIMO-A.
Now these 2 will not register with the AP.
We are using KPs 900Mhz yagis.
MAC :0a-00-3e-46-aa-77 Power Adjust 09/27/2019 : 13:46:24 UTC : Status : 6 Flag : 34 MAC :0a-00-3e-46-a9-fc Power Adjust 09/27/2019 : 13:45:30 UTC : Status : 6 Flag : 36 MAC :0a-00-3e-46-aa-77 Power Adjust 09/27/2019 : 13:45:28 UTC : Status : 6 Flag : 34 MAC :0a-00-3e-46-a9-fc Power Adjust 09/27/2019 : 13:45:14 UTC : Status : 6 Flag : 36 MAC :0a-00-3e-46-aa-77 Power Adjust 09/27/2019 : 13:44:53 UTC : Status : 6 Flag : 36 MAC :0a-00-3e-46-aa-77 Power Adjust 09/27/2019 : 13:44:40 UTC : Status : 6 Flag : 36 MAC :0a-00-3e-46-a9-fc Power Adjust 09/27/2019 : 13:44:38 UTC : Status : 6 Flag : 38 MAC :0a-00-3e-46-a9-fc Power Adjust 09/27/2019 : 13:44:22 UTC : Status : 6 Flag : 36 MAC :0a-00-3e-46-a9-fc Power Adjust 09/27/2019 : 13:44:10 UTC : Status : 6 Flag : 38 MAC :0a-00-3e-46-a9-fc Power Adjust 09/27/2019 : 13:43:58 UTC : Status : 6 Flag : 36 MAC :0a-00-3e-46-aa-77 Power Adjust 09/27/2019 : 13:43:56 UTC : Status : 6 Flag : 34 MAC :0a-00-3e-46-aa-77 Power Adjust 09/27/2019 : 13:43:44 UTC : Status : 6 Flag : 32 MAC :0a-00-3e-46-a9-fc Power Adjust 09/27/2019 : 13:43:35 UTC : Status : 6 Flag : 34 MAC :0a-00-3e-46-aa-77 Power Adjust 09/27/2019 : 13:43:30 UTC : Status : 6 Flag : 34 MAC :0a-00-3e-46-a9-fc Power Adjust 09/27/2019 : 13:43:18 UTC : Status : 6 Flag : 34 MAC :0a-00-3e-46-a9-fc Power Adjust 09/27/2019 : 13:43:06 UTC : Status : 6 Flag : 38 MAC :0a-00-3e-46-aa-77 Power Adjust 09/27/2019 : 13:42:57 UTC : Status : 6 Flag : 34 MAC :0a-00-3e-46-a9-fc Power Adjust 09/27/2019 : 13:42:46 UTC : Status : 6 Flag : 38 MAC :0a-00-3e-46-aa-77 Power Adjust 09/27/2019 : 13:42:45 UTC : Status : 6 Flag : 34 MAC :0a-00-3e-46-aa-77 Power Adjust 09/27/2019 : 13:42:32 UTC : Status : 6 Flag : 34
On our 900MHz AP's we typically use a SM Receive Target Level of -55dBm. If you have SM's that are very close to the AP, then you'll want to use lower gain antennas and again, try to get the RSSI to -55dBm. The messages that you're seeing are normal and are simply the AP automatically adjusting the SM's TX power to conform to the "SM Receive Target Level" that you've set. The TX power can change because of attenuation due to changing nNLOS conditions and/or modulation levels.
900MHz can be very tricky... you might need to change channels, and/or decrease the channel width, enable the high band pager filter option if you see a lot of noise up there, use a more directional antenna on the AP, or submit an offering to the 900MHz gods for a stable link to occur.
How close to the AP are these SMs located? As Eric mentions, if they are very close, and you have higher than normal gain antennas (like the KP Yagi) attached, the dynamic range of the SM Rx may not be able to reduce enough to maintain a stable connection.
However, as Eric also mentions, those messages in the log are indeed normal as the SM has ATPC (Automatic Transmit Power Control) functions, whereby the SM continually adjusts power to try to get to RSL of whatever the target is set to.
First, sorry for the late response. What software are you running on AP and SM? I made a small improvement in this area in 16.0.1 on the SM.
Yes, power adjustments are normal. However, in this case if the SM cannot register due to Power Adjust, something is wrong here. (Stating the obvious, sorry.) In this log the SM is hitting the AP at too low of a power but isn’t transmitting at its max power for some reason.
Radios can go down as low as -30 dBm transmit power (except 450m). Sometimes this failure could be because at Registration the link is assumed to be symmetrical path loss uplink and downlink. Do you have the external gain field set properly on the AP and SM?
Yes, you can limit the SM's Transmit Power. Configuration -> Radio -> Enable Max Tx Power. Then set max power level. Note, the AP might still adjust the power level down, but this will provide a cap for it.
In order to get the SM registered in this scenario, one workaround would be to increase your AP's setting: "SM Receive Target Level".
If you're still seeing problems, could you email me the http://<IP_addresss>/engineering.cgi of the AP and the SM? charlie.galik@cambiumnetworks.com.
This antenna is very close, per KPs recommendation we have tilted it down some but still receive the same message.
There are other antennas that are actually closer and seem to not have an issue, and a stronger signal. We've even turned the transmit power down on the AP and replaced the SM at the trouble customer and yet we still receive the message.
I just upgraded all of our APs and SMs too 16.0.1.1 last week and I am still seeing the same message. We are hosting our own cnMaestro so no cloud based.
Do you have the external gain field set properly on the AP and SM? (What is the best practice for this setting). This is our 3rd PMP sector, 2nd running an Omni. It is a very small town so all SMs are within 1 mile but it is wooded.
Yes, you can limit the SM's Transmit Power. Configuration -> Radio -> Enable Max Tx Power. Then set max power level. Note, the AP might still adjust the power level down, but this will provide a cap for it.
In order to get the SM registered in this scenario, one workaround would be to increase your AP's setting: "SM Receive Target Level".
We currently have the SM receive target level on the AP set at -52. So you'd recommend maybe trying -55 or -60?
The External Gain should be set correctly to what the external antenna's gain is. I believe that's what this issue is here. I'll work with you to investigate it.
As far as "SM Receive Target Level" setting, it depends on the site and the interference. I recommend keeping the whole site the same. If there is no interference, you can go as low as you can for your SMs to get 8X in the uplink direction. It does not require a reboot to so within two minutes, every SM will have adjusted their power to the new setting. Different noise levels and even different products (like 450m's high uplink gain) make this not a cookie-cutter answer, but dependent for each site.
MAC : 0a-00-3e-46-a9-fc Power Adjust 09/27/2019 : 13:42:46 UTC : Status : 6 Flag : 38 MAC : 0a-00-3e-46-aa-77 Power Adjust 09/27/2019 : 13:42:45 UTC : Status : 6 Flag : 34 MAC : 0a-00-3e-46-aa-77 Power Adjust 09/27/2019 : 13:42:32 UTC : Status : 6 Flag : 34
Also have the same problem does the Flag mean anything? Flag 38 or 34. I also encountered Flag 48
MAC : 0a-00-3e-46-aa-77 Power Adjust 09/27/2019 : 13:42:32 UTC : Status : 6 Flag : 34
kent,
This log is a registration rejected due to do Power Adjust. When the reason is Power Adjust, the Flag is used to say how many half dB the SM was off from the "SM Receive Target Level" setting. In this case, 34 means the SM was 17 dB lower than expected. If a SM is not at max transmit power, and is within 15 dB of the "SM Receive Target Level" then it is allowed in. So you can see this SM is right on the edge of being allowed to register.
Do you have the External Gain settings configured properly on AP and SM?
If you are still seeing this issue, you could collect http://<IP_address>/engineering.cgi files you could email them to me at charlie.galik@cambiumnetworks.com and I would take a look. I would recommend 16.0.1.1 as I did a minor fix in this area in 16.0.1.
Thank you for your reply. We did upgrade to 16.1 unfortunately still have no luck. but since it's just a couple of SM on different APs, we will just gonna replace them. It might be another Radio-Not-Calibrated case?
Thank you for your reply. We did upgrade to 16.1 unfortunately still have no luck. but since it's just a couple of SM on different APs, we will just gonna replace them. It might be another Radio-Not-Calibrated case?
kent,
I'm not sure you need to replace these and I'd rather save you the truck roll if possible. If the radio isn't calibrated it should show it at the top of the web page in red letters. Do you see that?
Sorry to repeat myself, but do you have the External Gain settings configured properly on AP and SM?
If you are still seeing this issue, you could collect http://<IP_address>/engineering.cgi files you could email them to me at charlie.galik@cambiumnetworks.com and I would take a look. I would recommend 16.0.1.1 as I did a minor fix in this area in 16.0.1.
We think we found the problem, the AP seems to have a problem on its Horizontal Antenna. Link Status showed a 20 dbm difference between the Vertical and Horizontal antenna.
Based on expereince, most of the Radio Not Calibrated SMs typically would still connect to the AP, but we also have cases wherein RNC SMs were not able to connect, not sure if it was just a coincidence, but we only discovered it when it was brought to our office by our field techs.
External Gain settings configured properly on AP and SM - I was told we intentionally set it differently as most of our SMs are situated where there are lots of trees.
We think we found the problem, the AP seems to have a problem on its Horizontal Antenna. Link Status showed a 20 dbm difference between the Vertical and Horizontal antenna.
Based on expereince, most of the Radio Not Calibrated SMs typically would still connect to the AP, but we also have cases wherein RNC SMs were not able to connect, not sure if it was just a coincidence, but we only discovered it when it was brought to our office by our field techs.
External Gain settings configured properly on AP and SM - I was told we intentionally set it differently as most of our SMs are situated where there are lots of trees.
kent,
Glad you have found a problem.
Correct, radios who have lost their calibration will have trouble registering. These need to be worked with customer support to fix their calibration or be returned.
The External Gains should absolutely be set differently if there are different antenna gains on AP and SM. If they are not set properly, it is another possibility to get this error.