I posted previously about an SM that had great RSSI and Jitter but the AP showed jitter around 12/13. This is the same SM. (We increased the AP max distance as suggested to 9 miles as well - no change). After it ran for a week on 2X Hardware it had over 400 re-registrations and 120 registrations. Trying to increase stability we’ve disabled 2X and set both ends to Software scheduling. Jitter on the SM now shows similar to the AP (2/3). RSSI seems slightly higher than previous.
The stats for 24 hours on Hardware Scheduling/2X
LUID: 002 : MAC: 0a-00-3e-90-64-2b State: IN SESSION (Encrypt Active)
Site Name : Campbell Drive
Software Version : CANOPY 7.0.7 Mar 02 2005 15:06:58
Software Boot Version : CANOPYBOOT 3.0
FPGA Version : 021605 (DES Sched)
Session Timeout: 6, AirDelay 147
Session Count: 24, Reg Count 19, Re-Reg Count 17
RSSI (Avg/Last): 1227/1229 Jitter (Avg/Last): 10/10 Power Level (Avg/Last): -79/-79
DnRate: 20000 DnLimit: 500000 UpRate: 20000 UpLimit: 500000 (kbit)
Rate : VC 18 Rate 2X/2X
And 24 hours on software
LUID: 002 : MAC: 0a-00-3e-90-64-2b State: IN SESSION (Encrypt Active)
Site Name : Campbell Drive
Software Version : CANOPY 7.0.7 Mar 02 2005 15:06:58
Software Boot Version : CANOPYBOOT 3.0
FPGA Version : 020205 (DES)
Session Timeout: 17, AirDelay 147
Session Count: 17, Reg Count 14, Re-Reg Count 2
RSSI (Avg/Last): 1307/1307 Jitter (Avg/Last): 2/2 Power Level (Avg/Last): -78/-78
DnRate: 20000 DnLimit: 500000 UpRate: 20000 UpLimit: 500000 (kbit)
It seems that the SM just disappears for 5 - 90 seconds occasionally. I’ve seen it happen twice and both times I was unable to monitor the AP’s Sessions page prior to it occurring…I’ve run the spectrum analyzer for >5 minutes several times (although not at the time that it’s happening I don’t think) and both ends look clean - everything is -95 to -90… the rest of the spectrum is a little higher and around 928 to 930 it hits -65.
As mentioned befor this is non line of sight at approx 4 miles. This is the only SM on this AP…It almost looks like the session timer expired and the SM gets booted - I’ve watched the session stats and seen the timer go as low as 3 before resetting to 30. Can this value be increased - would that help stabilize this link, or is this just the nature of the beast ? 
probably a cordless phone in the neighborhood is killing you for short periods or a scada transmission, although they tend to be a little more regular and predictable
Thanks for the suggestion - If it is interference, would replacing the 65 degree panel on the AP with a narrow beam yagi help at all - there’s not much between the AP and SM as far as residential/industrial development goes - it’s almost completely open countryside… there are power lines (not “highvoltage long-haul” lines) about 50 yards from the AP and they would be in it’s fresnel zone.
After switching to SWS, there was one customer that was still reregistering at unacceptable levels.
I did manage to catch a spike on the spectrum analyzer once, but other then that the RF environment is clean.
Moving him to a yagi (13 dB, 30 degree beam width) significantly reduced the registrations. Still happens 3-6 times a week (more then we are seeing on our others customers), but the yagi did produce and “night and day” diference.
YRMV of course, but it worked pretty well in this case.
Rather than switch to a Yagi and cut my coverage in 1/2 plusI was thinking that the noise may be coming from below, or beind me and the yagi would only be more susceptable to the back end, so I decided to move up the band 6 Mhz at a time first and see what happened.
Surprise – up where the noise is about 50% higher I’ve had a solid link for 5 days - one re-reg and that’s it. Jitter is worse - 4-6 on both ends, but the link seems solid.
So - what’s the worry of having jitter above the recommended level of ‘4 or below’ ??
Thanks,
B
That’s great that you’ve had success.
I’m rather locked in to my frequency usage though. With an entire 6 AP 360 cluster, changing frequencies more then a MHz or 2 would start steping over my other APs.
Anyway,
cheers
Do you all highly recommend sticking with just one freq when it comes to AP-SM’s?
We have 2 900 AP’s, one facing north, the other south, 1 2.4 omni, and 1 5.2 sectorized facing south. When configuring SM’s we just select all the freq. and not just 1 or 2.
I have heard on 2.4 the SM will register with the first Freq. it is able to connect to, even if that is not the same freq the AP is on. Is that true?
Thanks