Just running something by you guys-

Our main broadcast point has been a 900MHz HPOL MTI omni for some time now. We just switched it over to two HPOL MTI 180degree sectors.

Currently to get all the clients back online I have them set with identical configurations (ie color code, frequency, downlink percentage, etc) with the sector ids set to different numbers (0 and 1) and a sync cable in place giving sync to the other AP.

I’ve got a few clients that are dropping in and out and some that never came back up after the switch. I guess I’m kind of thinking I may need to operate at separate frequencies on both APs because even though they are back to back North and South, I’m sure there is some self-interference going on. I’m also thinking separate color codes for the customers in the middle that seem to be having the connectivity issues to force them on one AP or the other.

Would you all agree with my assessment or is there something else I might be missing?

Couple things to keep in mind: low noise floor (-87 or -90 on most of the spectrum) and we are not using GPS timing as we’ve not ran into a need for it yet.

Thanks in advance.

We answered our own question. A change of frequency on our north facing AP brought everyone back online.

You said you are not using GPS timing.

Are you even putting one AP as the timing master and the other as the timing slave, and then running a sync cable between them?

Sorry, forgot to mention that yes, we have a timing cable and one ap is generating the other is receiving sync.

Like I say, the problem actually seemed to be related to the fact I had both APs on the same frequency. I’m guessing the clients directly in the middle (where the antennas meet back to back) were unable to differentiate between the APs and could not register because of this.

It’s been performing very solid and efficiently since I made the change.

Yes, each on one of the non-overlapping channels at 906, 915, 925.

since there are only two units, I would use 906 and 924 providing as much separation between the two as possible.

That’s what I ended up doing, Jerry - worked great.


To the east of our north/south AP sector about 15 miles and to the west about 8 miles are two additional 900 aps - the one to the east has a 9db pacwireless HPOL omni and the one to the west has a 11.5db MTI HPOL omni. Both are operating at 915 and both are generating their own sync.

Not using any GPS sync are we creating self-interference from the APs in the middle? Since the changeover my AP to the east I’ve had to completely disable 2x mode and crank the power on all SMs, still not completely getting rid of the re-regs. The one to the west has exhibited some issues but not near the magnitude of what the one in the east has seen.

Any ideas?

Most definitely self interference. I have seen 906 affect 924 when not in sync.

Put PacketFlux sync pipes on the other two towers.

Will the ones in the middle be alright without the GPS sync? I should note this is something we planned on implementing anyway, but I was hoping to put it off for a few weeks when the weather was warmer. Bummer.

Canopy 900 hears other 900 for a very very long way.

Really needs sync to run at the optimum.

Thanks again Jerry.