Marlon K. Schafer (509) 982-2181 wrote:

> Scriv needs to hire a good consultant to come check things out!
> big grin

Know any? :D

The hard part there would be that it's not, in any way, predictable.
We've gone several weeks at a time without this problem appearing, and
had days where it showed up several times. Most of the time, I only see
it in our network monitor logs, as it came and went within a minute or
two. Assuming it's some massive source of interference, I imagine it
would be very difficult to triangulate it. (By the time I call even one
person to say "fire up your spectrum analyzer," it's gone.)

> First, as I recall, this ONLY effects towers within a 15 mile radius. 
> But it effects ALL towers within that "cell".  right?????

Yep. I had a nice map that showed all our towers, and which ones were
(and weren't) affected. I may try to dig that up, or recreate it.

> I've seen customers download or upload massive files (usually ptp stuff)
> and open up hundreds of connections and whack a tower.  If it's the
> right tower and interferes with the other towers anywhere near it.

That's probably not the case, as we've recently taken measures to reduce
P2P traffic (a Mikrotik box and some pretty harsh traffic shaping
rules). Also, I've seen P2P traffic before, and while it usually slows
down that specific AP, I've never seen it affect our backhaul or other
nearby towers.

We're pretty good in terms on "not walking on ourselves." There are no
overlaps (AFAIK) between our towers if they're within five miles or so
of one another, and facing towards each other. We are using the whole
2.4GHz spectrum, of course, but not all of it in any one place.

> There are times when radios go bad and start transmitting OUT of band. 
> I've seen wifi stuff flood the whole band.
> Amps can do that too.

We do have a couple of amps here and there, but I don't think any of
them are over 200mW. That'd have to be one heckuva runaway amp to cause
that much interference.

If it were a bad radio, wouldn't it be a more frequent problem instead
of one that randomly shows up for a minute or two here and there?

> Is it possible that your 900 and 5 gig gear ALWAYS has a router at the
> cpe and the 2.4 doesn't?  As I recall the Waverider gear, the ap is a
> router, that would keep things that would flow on a switch off of the
> 900 system.

Not even close. We've got folks with 900MHz gear and 5.whatever that
just plug their radios straight into their PCs.

(At least I know that's the case with the 900MHz stuff, as we have a lot
of residential customers on it; I can't, off the top of my head, think
of any 5.3/5.8 customers without a router, but we don't have that many
of them - we're mostly using those bands for inter-tower backhaul.)

> Are there any towers that are sectorized that point in a direction that
> makes them unaffected?

I wish... Two of them have two 180-degree sector antennas facing in
opposite directions, on opposite sides of a water tower (i.e. with
twenty feet of steel and water between them), and both sides are
affected equally.

David Smith
WISPA Wireless List:



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