900 signal loss between certain times.

Greetings to one and all.

In one area of our Canopy setup, we have customers losing signal between 10am and 8pm local time (CDT). We have an omni set at 180 ft on a 350 ft tower.

The customers with the signal loss are in the south/southwest quadrant around the tower. We do have people NOT losing signal in this area, but right now they are the exception. Also note that these people are on the opposite side of the tower from the omni. We have pretty much ruled out a leg blockage, temperature(though through several other threads i see that this is probably the least likely), any outside interference(no other 900mhz gear at all in the area), placement of gear on customer house, LOS issues, and most all other weather issues.

My question is this: Could the signal loss be caused by a bad sector in an omni? or is that just grasping at straws?

Also on a further note, there is an backhaul at 350’ and an AP around the 75 foot mark. I know that CAT5 is limited to 300’ could this be an issue as well?


I wouldnt rule out the fact that the signal could be bouncing off the tower leg. An omni with one side pointing directly at a metal object only a few feet away is not the best scenario.

Are there any other 900 AP’s on the tower? How does the spectrum analysis look from the SM? Did you perform a spectrum analysis at the AP and if so what channels showed the strongest signals? What were the values?

Yes to spectrum analysis. We have found that there is another motorola 900 on another tower belonging to someone else. They were operating on 906 freq color code 24. We are operating on 915 color code 10. The omni is the only AP we have on said tower.

Spec AN. was taken from several different directions from both towers from 1 to 4 miles.

During our troubleshooting (we had 13 customers offline, none of which had the same length of time with us from 8 months online with no other issues and the most recent had been on for 5 weeks), which was attempted during the heat of the day, it began to rain. At that point in time, the tower got rained on, but not all of the customers did. Everyone came back online after the outside temp dropped 30 degrees.

THere was spec an done from the SMs. During the morning, everything looked ok, then we went back to same locations attempted to gain signal from our AP and spec an showed no noise on our gear, but the other company’s gear did show. We were not able to get any AP info from our gear at all.

While aiming at our tower, our freq was putting out the most noise. As we sweep past our tower the noise drops. As we swept past the other company’s tower it showed that there freq was the strongest.

We believe the AP on tower is somehow affected by heat, as it drops random customers in the heat of the day.

Would AP replacement be the best fix for these issues

Are you or the other company using a CMM for timing?

What software release are you running?

multiple software releases are being used. unsure about timing