Interference with Microwave Data Systems (MDS)

Has anyone out there run into an interference problem with Microwave Data Systems? We have a 900Mhz AP cluster on a tower which happens to have a 900Mhz spread spectrum MDS system on it also. Now the company that is using the MDS system is having problems receiving signals on their system. We’re experiencing obviously some interference also. Has anyone run into this before and come up with any type of solutions?
We’ve spoken with the company and they said they’ve tried turning off “zones” and have not seen anything come of it. We’re using the standard 906, 915, and 924 frequencies.

I have dealt with this quite extensively.

The fact that you have a 3 AP cluster, configured with the 3 non-overlapping channels, the MDS is SOL.

I am assuming the MDS gear is either a Transnet or iNET, and these models are capable of hopping around or between canopy APs, but since you have the entire band used, something will have to give.

1. Is it possible for you to swap out two APs and install a single AP with a 120 deg panel? this would free up enough space in the spectrum for the MDS gear to work in.

2. Is it possible for you to take out all 3 integrated APs and install a single AP with omni? This would free up maximum space for the MDS gear.

It could turn into a big pissing match between you and the MDS user/provider. You will definitely have to work together on this, or no one wins.

This is the beauty of Spread Spectrum…anyone can use it.
This is also the bad thing about Spread Spectrum…anyone can use it.

Good luck.


That’s the answer i was afraid of. We’re actually using 6 APs in the cluster, 60 degree integrated. Yeah we’ve tried any combination of shutting some APs off with them and haven’t found a solution yet.

Could try alternating freq.
AP1: 906
AP2: 915
AP3: 906
AP4: 915
AP5: 906
AP6: 915

That would free up the uper end of the band.

Of course this could be done a couple ways. Could use 906/915, 906/924, 915/924 or any other combination of non-overlaping channels

We use MDS Inet gear for links between sites for our VHF IPMobileNet system and on one hill we could not get the Canopy and MDS stuff to work together. We were always skipping zones in the MDS radios and trying to work around the Canopy (the 900 Canopy bothered the MDS before the opposite took place). The links would work and then the packet loss would go over 10% which was unacceptable. We ended up changing the MDS equipment over to Canopy 2.4 and it made everything better.