ePMP 3000 and Force 300 SM

Hi all, just wondering if anyone has experienced any issues with force 300 subscribers downlink rssi taking a huge dive for no reason? I have some subscribers dropping 10-12db, ie subscrber at -67db now -78db, there are 30 subs on the sector, some have dropped 5-8db but all in all every sub has suffered signal degrade… tried remote reboot and physical reboot of sector, running 4.6.1RC27 on AP and Subs… issue was happening before upgraded from 4.6 to 4.6.1RC27. Puzzled and confused.

Huge interferences ?
Look for a different frequency.

does it correlate to a time of day? or just sudden and specific to a small area?

time of day affects signal propagation, but if it is just a small subset of subscribers then go out and do a spectrum scan in the area affected with a F300. If it is just upstream signal, look at alignment and multipath issues.

Tried different frequency, still same result. I ran the spectrum analyzer on the AP for 12 hours…

Nothing shows up in the bottom graph of the analyzer… in the detailed interfere details I see a nanostation 20 mhz at -81 db. So Im not sure if interference is an issue but who knows.

It seems to be worse at night, for example a SM that was showing -80 to -70 last night is right now steady at -60, there are a few SM with this same behavior. Been using this same frequency for quite some time with no issues. I have a ticket open with support and they noticed a few issues on AP log and one of them was GPS sync loss.

Using a system like cacti or mrtg, pull a graph to show time of day vs signal strength. This is sounding like a multipath issue and will be very difficult to solve since it can be anywhere on the path. The graph will give you a more deterministic view to work from.

You may need to go sit on the roof during the poor signal and mive the SM around the roof to get a signal map of the roof. This is time consuming but will give you the best location for the SM and you may need a 10ft pole to get to a higher point (3rd fresnel issue testing).