LOL  Love those palm trees!  I used to live there, don't envy you a bit.  grin

I normally turn my radios way down anyway.  With the sensitivity of today's 
radios there's no need for hot links.

30 to 35dB of s/n is, in my not so humble opinion way too much.  That's well 
within the range of multipath signals.  Lower power may actually help this link 
perform better.

The fact that the rssi is frozen is strange.  If there is no link there should 
be no rssi either.  I wonder about the health of the board.  This sounds a lot 
more like a lockup than it does a signal issue.

I don't know anything about the configuration that you have built so I don't 
know what it should be telling you.

Is it possible for you to just replace the ap with something more standard and 
newer?

I can do a really good AP for under a $500 these days.  With good boards, an 
amazing hinged enclosure, lots of room etc.  We've gotten things dialed in so 
that there is NO need for 25 tools, tape or anything up on the tower.  A screw 
driver and crescent wrench is about all that's needed to swap parts, including 
antennas.

Sometimes it costs more to try to fix a problem like this than it does to just 
replace the gear.
marlon

  ----- Original Message ----- 
  From: Tom Sharples 
  To: Marlon K. Schafer (509-982-2181) ; WISPA General List 
  Sent: Thursday, November 01, 2012 5:53 PM
  Subject: Re: [WISPA] CM9 Rx blocking problem?


  When the problem happens, the rssi is "frozen" so I suspect there's actually 
no connectivity any more. Definitely no data. I haven't been able to get 
someone to look at the other end while it's happening, to see what they see.  
During normal operation the s/n is around 30 to 35 db on the varous legs, and 
bandwidth, latency, etc is as we would expect. As you probably know the CM9s 
only put out around 50 mw but that's usually adequate for short-haul apps like 
this.

  At present I can't access the system at all,  because the client has 
apparently allowed palm trees to grow into the path of the 5-mile (XR5) ptp 
backhaul we put in to feed it :-( and with today's rain it's killed the link. 
Once those are cut I should have access again and can run more tests.

  Thanks,

  Tom S.

    ----- Original Message ----- 
    From: Marlon K. Schafer (509-982-2181) 
    To: Tom Sharples ; WISPA General List 
    Sent: Thursday, November 01, 2012 11:00 AM
    Subject: Re: [WISPA] CM9 Rx blocking problem?


    Are you loosing connectivity to the client radios or only loosing data from 
them?

    What do your link stats show?  Signal quality etc.

    What are your eirp levels at normally and during the events?

      ----- Original Message ----- 
      From: Tom Sharples 
      To: Wireless@wispa.org 
      Sent: Wednesday, October 31, 2012 1:46 PM
      Subject: [WISPA] CM9 Rx blocking problem?


      Hello all,

      We're seeing an odd problem at a customer location in Honolulu. About a 
year ago, we set up a pretty conventional point-to-multipoint 5.8 Ghz setup for 
video surveillance - a dual-radio gateway node attached to a pair of sector 
antennas, and 4 client radios (2 on each sector) attached to IP cams. The 
client radios are between 1/4 to 1/2 mile away from the gateway node. This is a 
multi-building industrial project in a fairly heavily polluted (RF wise) area. 
There's a Home Depot and Lowes nearby with equipment on all 5.8 Ghz channels. 
However our radios scan well above the noise floor.

      Our equipment uses pcengines alix boards running our own linux-based OS 
and CM9's using standard madwifi-style drivers. Same thing we've been using for 
years.

      This installation worked well at first. However, we are now seeing a 
situation in which both gateway radios suddenly stop receiving data from the 
downstream clients. This lasts from 5 to 20 minutes or so and then magically 
fixes itself. When I ssh in during the problem, there'e no indication of 
low-level driver problems or crashes, everything looks normal except for the 
sudden lack of data and connectivity with the client devices. 

      This installation is near Pearl Harbor and there are constant overflights 
from military aircraft. I'm wondering if this is a sensitivity issue to e.g. 
radar or some other high-powered signals from these planes. I've seen things 
like this before but never lasting up to 20 minutes. Would we see an 
improvement by switching to XR5's? We don't normally use those on short hauls 
like but they have better OOB filters than the CM9's. Thoughts?

      Thanks,

      Tom S.



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