Wrong Frequency Beacon Received , 900MHz

I have a very high count on this register, 628 in less than 1 day.
Wrong Frequency Beacon Received

I have done spectrum analisis and can’t find anything, all ok.
The AP is in a rural, very rural zone. No Phone, no chellphones, no beepers, almost no radio.

I know the jitter is very high (~10/5 ) Hardware scheduling, but should that cause a frequency problem also.

Site Name : Problem
Software Version : CANOPY 8.1.4
Software Boot Version : CANOPYBOOT 3.0
FPGA Version : 041006 (DES Sched) P9
Session Timeout: 0, AirDelay 197 (approximately 5.48 miles (28959 feet))
Session Count: 57, Reg Count 62, Re-Reg Count 71
RSSI (Avg/Last): 1402/1404 Jitter (Avg/Last): 10/5 Power Level (Avg/Last): -75/-75
Sustained Uplink Data Rate (APCAP): 20000 (kbit)
Uplink Burst Allocation (APCAP): 30000 (kbit)
Sustained Downlink Data Rate (APCAP): 3000 (kbit)
Downlink Burst Allocation (APCAP): 30000 (kbit)
Low Priority Uplink CIR (D): 0 (kbps) Low Priority Downlink CIR (D): 0 (kbps)
Rate : VC 18 Rate 1X/1X

This is a one link, One AP and one SM Only, 900MHz
UP TIME is only 19 Hours.
The link is 5.4 KM.

Is this radio in need of calibration?
OR what is the problem?

Did you ever find a solution for your issue or even what ‘Wrong Frequency Beacon Received’ means?

I have noticed the same thing on a couple of our SM’s but haven’t yet been able to figure out what is causing it. We have managed to fix it by replacing the SM but I am hoping that we can find a better fix for it.
To expand on the amount of avaliable information:
AP P9 Board 8.2 firmware part of an AP Custer Synced Via a CMM.
SM P10 Firmware has been 8.15 & 8.22

All of the units I have seen do this have been in the field for some time and then without anything visibly changing start to have problems.

Anyone have any additional ideas or has seen this eror before?

Cheers
Simon
Broadband Net

mimbanis wrote:
Anyone have any additional ideas or has seen this eror before?


I can tell you what this means... The AP sends a beacon 400 times a second. Among other things, this beacon contains the frequency the AP is transmitting on. If the SM receives a beacon message while listening on a given frequency, and the beacon message indicates it was transmitted on a different frequency, then this counter increments.

My guess is that you either have some sort of interference which is corrupting the beacon message such that when it is decoded it appears to be from an AP on a different frequency, or possibly you have an AP on an adjacent frequency and the SM is locking onto and decoding the beacons from it. My understanding is that a SM will actually lock onto a slightly out of frequency signal (such as the one setting up or down in the 900Mhz or 2.4Ghz band) and be able to mostly decode it.

-forrest