This is our third implementation with using 3 Til-Tek 120 degree antennas and Canopy 900mhz connecterized AP with the CMM1070K. This last implementation started off great. It is a new site with a direct fiber feed. We install the antennas 240’ on the tower and have customer 20 customers on our North/West (Refer to as Red) antenna and 15 on our North/East (Refer to as Blue) antenna. The third antenna does not have any customers at the momement. Things worked great for 4 weeks and then the problems started.
We lost 15 customers on our Red antenna. These customers had great signals 65dbm with 1 to 2 jitter and located about 4-5miles from the tower. Customers on our Blue antenna did not have a problem. We changed frequencies etc… nothing helped. Go to the customer site and under the AP Evaluation it shows both the Red and Blue radios. I had the Red radio replaced and the issue remained. What I started to realize is that the customers who were going out were very close to the cross-over between the Red and Blue vector.
Just by chance, when I rebooted my Blue radio all of my customers that were out on the Red came back online and as soon as the Blue radio powered back up the Red customers would go back offline.
Red radio is on 906 colorcode30
Blue radio is on 912 colorcode31
Now, the issue has changed over the past week. Now the customers on the Blue are going down and the Red remain online. Dowload Rate is 75%, Hardware slot 0, Distance is 10miles settings are same across all three radio. Any insight would be appreciated.
A couple of things:
- Having 0 control slots means there is no air time dedicated to management communication with the radio. This should be left at 1 for such a small amount of users and turn up as you go, or if you need to coordinate with another WISP
- You are using overlapping channels. You will need to use center frequencies of 906, 915, and 924.
- Have you performed any spectrum analysis to see if there is a new source of noise? Both the SMs and APs can perform this feature, though with the SM version you get a big nasty hump from the AP.
- Is this equipment synchronized via GPS, or daisy-chained self-generated? Is it within range of another 900 MHz Canopy deployment?
On 900MHz you’re wasting a half-slot of air time using an odd-number control slot. If you use the frame calculator you can see this. We run ours at 4.
Salad is right though, you are overlapping your frequencies - you need to be on 906, 915 and 924 in this deployment to not overlap and step on yourself. Obviously the money is spent and it may not be an option, but I consider a 4 sector array a superior deployment because you only need to have two channels in 900MHz clean instead of all three (one channel on your north/south APs and one on east/west).