My CPE can not attach to the access point on my BTS.

I got to my client's site, I plugged my laptop to the POE of the radio; and was able to log into the radio (eForce 180). I observed that the radio was not attached to the Access Point (ePMP 2000) which it was connected. I tried attaching the radio back to the Access Point but could not. From the Home Interface of the radio it is showing “Operating Frequency: Scanning”. I increased the antenna gain of the radio and also decreased it as well, but the radio could not attach to Access Point.

Please can somebody tell me what to do in this case? Urgent reply will be appreciated. 

I moved your post into the ePMP 2000 forum.

Are you saying the SM (Force 180) was connected to the AP (ePMP 2000) at some point in time, but when you arrived, it was not?

If properly configured, within range, and free from severe interference, the "Scanning" should find the proper frequency, then register to the AP.

Do you know the AP frequency parameters and are you sure it will authenticate the SM?  Might the SM have been misaligned somehow and no longer aimed toward the AP properly? 

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Anything displayed by the SM at the Monitor->Wireless page? It should be listing the APs that it is able to see during the scanning and, if it cannot register with the AP, it should display a reason why.


Thank you for responding to my mail.

Yes, the SM (Force 180) has been connected to the AP (ePMP 2000) for the past 6 months untill this incident. Actually, I have four clients attached to this AP at an operating frequency of 5965 MHz.The radios (Force 180) of two clients out of the four clients can not attach again to the same AP. The two clients that are still attached the this AP are on the same location (two SMs on the same mast) while the other two clients that can not attach to this AP are on diferent locations. The configuration parameters of the two SMs are still intact and the allignment still aimed toward the AP.

From Wireless page of the SMs, it lists my other APs, which gives me signal strengths of -82dBm unlike the preferred AP that gives me a signal strength of -64dBm. Each time I try to connect the SM to my preferred AP, it displays "SM network failed". I have to connect one of the clients to the other AP with a signal strength of -82dBm, which is really not a good signal.

At some point, the SM registers to the same preferred AP say for like an hour then de-registers and start showing "Operating frequency: Scanning"

Attached below is the spectrum analysis done on the SM of my clients.

Hello NnamO

In your scan for NISA@Prime, it appears the SM is seeing energy from a 80MHz channel, which is probably overlapping with your current channel. This enery will reduce your carrier to noise/interference ratio for that SM and cause connection issues. In your other scan, the adjacent channels appear cleaner, but to make sure there is no co-channel interference, you may want to turn your AP off temporarily, to make sure it is not hidding energy from other source on the same channel.


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Thank you Luis for your time.

I turned my AP off for 8 minutes, the SM is yet to register to the access point.

Attached below is my AP interface. Can you please check the pages and analyse for error(s)?

Also, can you suggest suitable frequencies using the previously attached spectrum analysis? That is, if it is freqency issue.

Please can you explain this line from your previous response "In your scan for NISA@Prime, it appears the SM is seeing energy from a 80MHz channel, which is probably overlapping with your current channel."

Thank you for your effort.

Hi NnamO,

Very difficult to find a good channel in your area, based on the scans. You could try 5875MHz (20MHz BW), but even that one is overlapping with some strong energy. If you have Force200 available, you could attempt switching the problematic SMs with Force200, to take advantage of the higher gain/narrow beam.


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Hello Luis,

Thank you once again Luis.

From my cnMaestro, the alarm notification on my APs says that "GPS software is out-of-date". Can this out-of-date firmare be part of what is affecting my SMs from registering to the AP? Attached below is my cnMaestro dashboard interface, please take a look and advise.

Hello NnamO,

Running an older version of the GPS firmware could prevent the on-board GPS receiver from working properly. It should not prevent individual SMs from registering. Having said that, it is recommended to upgrade to the latest GPS chip firmware at your convenience, as documented in this KB article.

Be adviced that GPS fw upgrade could take a long time (8-12min in some instances). Do not reboot or power down the unit until the GUI shows the reboot button highlighted in yellow and shows a notification in the Notification area of the GUI, that a reboot is required. Not doing so will disrupt the firmware update and will require the GPS chip to be recovered (can only be performed by Cambium Support).