I have two M2 bullets with 15dbi omni antennas. Both are on the same -2 channel and 5mhz band width. Distance between the two is about 3.5 miles. All other nodes (6+) are working ok.
- Node A is up about 140' and Node B is up about 50'. There is a clear line of sight between the two.
- Node A reports quality to Node B at LQ=100% and NLQ=9% (or less at times)
- Node A is also connecting to a similar bullet and omni at 16.3 miles distant. Distance set at 35,000 meters. LQ and NLQ 85%+ most of the time.
- Node B distance is set to 6,000 meters.
- When I can access Node B it reports the quality of Node A as LQ=15% and NLQ=100%
I have switched out bullet and antenna and ended up with similar results. I can only assume that there is some external factor that is affecting one or the other on that link. The questions are:
- Which one is suspect? I suppose Node B.
- What exactly is the LQ and NLQ telling me about which node?
- What other suggestions might you have?
My next course of action is to relocate Node B about 60-70 feet from its present location, although the height may be slightly lower, and there will be an obstruction of about 15 degrees width in one direction. Maybe it is simply interference from the elevator shaft it is presently mounted on, even though the elevator hardly ever runs.
Mark
When looking at the status screen LQ is "Now good I hear a node that is remote" and NLQ is "How good does that node hear me" where "good" is defined by measuring the number of information exchange packets that are lost on the link.
What is being described is that Node B can only bearly hear node A.
Items that can possibly cause this:
Node B has strong signals locally (such as another node inside a building, or on a car parked next to it that decrease the signal quality of Node A. or even other stray RF/EMI (its even possible for another wifi device to have bad filtering and be leaking out of band)
If on the latest beta builds a wifi scan will show wifi signals of each individual node and you can see if this node is down lower than the rest. You would also want this signal value to be compared against the Noise Floor, if the noise floor is lower at the tower but higher at node B node B will naturally have harder time receiving.
Node B could have terrain local to it that either blocks or reflects (multi-path) the incoming signal (trees, maybe even the elevator shaft if it has a large amount of metal).
These are just some starter items to look at.
My best guess is that on top of a building right at 400 feet away and 45 degrees left of line with Node A there is a rooftop with about 20 or so sector antennas of unknown frequencies facing all directions. May be WiFi interference?
The Node B antenna is only about 3 feet above the elevator shaft rooftop, but I cannot imagine what could be doing it.
Mark
Hey Mark,
One of the things we could do is take a Rocket M2 with AirOS installed on it to that site. We can use the AirView (spectrum analysis tool) to sniff and see if there are any devices on 2397Mhz in the area.
Darryl