Coexisting with Alvarion

Is there any good way to coexist with Alvarion and the FHSS that it uses?

I just installed a Canopy 9000 AP and am picking up large amounts of interference from another WISP using Alvarion.

They use HPOL antennas. I went VPOL (I know, I know) and I still pick up the Alvarion gear in the low -70’s.

The other WISP will not cooperate in any way so I only have workaround oppurtunity on my end.

In this case I’m not sure sectorizing will do any good. I pick up the Alvarion gear on all frequencies and it hops all over the place.

Any input is appreciated.

Sectors will definitely help for most directions except for the one that faces the Alvarion. If they will not cooperate you can just put yours up and let them deal with the interference for a while and I am sure they will be contacting you. You will have to make sure you get 100% link tests with a good margin when installing a customer.

You might also want to look into using only Yagi antennas for customer sites to mitigate some of the interference.

I am not sure if you should stay HPOL vs VPOL. I would highly recommend either Integrated APs or MTI brand 90* sectors.

Having both pieces of equipment in my network, Motorola completely chews up Alvarion.

Cooperation really is the key, but if they are not going to, I agree Yagi’s and leave it in place, they will not have any choice but to either convert to Moto or coordinate with you.


Since the other WISP will not work with you then I agree that the solution is to sectorize and use 906, 915, and 924 so that you do not self interfere. Configure all three AP’s to use the same Max distance, DL%, and control slots.

Try aiming panels in a way that the lobes overlap between two panels it at their tower. This will maximize your potential coverage area and minimize the area that you have limited coverage on the other side of their tower.

You will need to play with frequency assignments on the three AP’s to find a balance. Configure SM’s to be able to scan all freq’s, and use unique color codes on each AP. This way if you need to swap freqs between the AP’s the SM’s will just follow the color code and change freq’s automatically.

How much rejection are you getting going V-POL vs H-POL? If it’s not substantial, I would suggest going H-POL as Canopy really is designed for H-POL. Since the other WISP is the only other H-POL source, at least you know where it’s coming from and that the RF level is limited to 4W. V-POL is every high-power City, County, Fire, 2-Way, etc and it’s very difficult to predict where that noise is coming from.

As far as dealing with an un-coperative WISP, you need to cross all your T’s and dot all your I’s.

First, write a polite letter to the other WISP requesting a meeting to co-ordinate frequency usage. File a copy and any replies. If they do not reply, send another letter. Keep sending them once a week. Hopefully they will respond with a letter offering to co-ordinate, but I doubt it. More likely any response you get will be declining your request for a meeting. If you get this letter, file a complaint with the FCC and copies of all the letters. The next letter they get will be from the FCC. After 3 unanswered letters, file a complaint with the FCC.

In the mean time, start putting up SM’s using Yagi’s. As you add users, the other WISP will start having problems. Then they will have to negotiate on your terms.

If you are going to play it this way, you HAVE to do it straight. As tempting as it is, DO NOT intentionally disrupt the other WISP. Just set up your system as per the Moto guidelines and start operating. Do NOT run anything over the max power. You don’t want the other guy complaining to the FCC that you are running over max EIRP. Your AP’s can run up to 12.5dB antennas. SM’s with 13dB Yagis can run at full Tx power, and 18dB Yagis need to run at 21dB Tx Power.

Good luck and be DIPLOMATIC!!!