Hi there,
We have a little ongoing discussion on whether it’s better to use 3 x 120 Degrees Cyclone Canopy Access points or the 6 x 60 Degrees access points. Both types
has a 200 user restriction which already leans me over in favor of the 60 degrees solutions since it’s virtually doubles the amount of customers per 120 degrees and spreads your users out over more than one frequency. Also , I guess a 60 degrees Antenna only receives interference on a 60 degrees angle where as for the 120 Degrees AP it receive interference on a much larger angle.
The only real benefit I can see from using a 120 Degrees AP is that it’s got a larger , more powerful Antenna on it then it’s 60 degrees counterpart.
Some advice would be greatly appreciated….
why are you restricted to 200 users? we have some 5.7 ap omni’s with over 80 people on them with no problems. 80 per ap, 6 ap’s, thats 480 subscribers
A Motorola Canopy AP has a 200 SM restriction on it. Anyway , this isn’t the deciding factor. I’m more interested on advice where it comes to overall performance between a site containing 3 x 120 Degrees Access points and one with 6 x 60 Degrees Access points…
Personally I like the idea of a 4 sector array - you can limit yourself to only using two channels, where as a 3 and 6 sector setup you are looking at a minimum of 3 channels in order to mitigate self-interference.
Things can get really ugly if you find that all of a sudden a chunk of your frequency band is no longer usable. I don’t think you’ll come across very many scenarios where you are actually getting 200 users on a single AP - 80-120 is probably more realistic. The extra capacity is nice in larger deployments but only if you have the available spectrum to do it.
Yep, I’m experiencing that right now. I started out with 900MHz - 3 120 degree Tilteks. I have one AP that has 50 subs on it. Soon I will add another antenna and go to 4 90s.
I agree, 4 90s offers more flexibility and room for added growth.
wifiguy wrote: I don't think you'll come across very many scenarios where you are actually getting 200 users on a single AP - 80-120 is probably more realistic
I agree.
If you plan to connect more than 600 customers on the full cluster (360°), you go probably better starting with 6x60 integrated AP. If you don't have such population density, using 3x120° will cost less and let you gain about 7-8 db EIRP.
a similar note is dont cheat your coverage. we tried getting away with 4 integrated APs the 60 degrees is 60 degrees, not 90. anything past a couple miles in the fring and yer sol
The 200 users limit isn’t bothering me that much , I’m more interested in trying to minimize interference from other service providers in the area. My argument were that the smaller coverage area per AP the less interference we’ll get for that specific sector the AP is covering. For instance , a 6 x 60 degrees high site would have less interference then a 360 degrees AP or a 3 x 120 degrees site for that matter.
All this is based on my assumption that an access point only receives interference in its coverage area……
Depends on how close your competition is to your tower. If they are several miles away, then sure. If they are just a few blocks away, it won’t matter what you do.
About the only way to deal with interference is to hope your competition is Canopy so that you can coordinate sync, otherwise you just have to space things as far apart as possible. I have one Canopy AP with a noise floor of -70. Needless to say it doesn’t get a whole lot of new subscribers added to it.
I would still recommend the 4x90 approach. You’ll only use 2 channels in 900MHz or 2.4GHz leaving one channel open for a disaster (assuming of course your spectrum is clean to begin with).
How do I go about coordinating sync with competitive ISPs that’s also using Canopy?
You’ll actually have to directly contact them and try to find out their settings and see if you can reach a compromise (either you use their settings, they use yours, or you settle on something in-between). Settings that affect synchronization are max distance, control slots and downlink %. You could also use the frame calculator in Canopy to find settings to match sync - your goal when using this is an uplink SQ start of less than 250.
IMO, Jerry Richardson came up with the best way to approach your competition: inform them that you are using the same frequency band and that you fear you might be causing them interference (yes, you causing them interference - make it look like you are out to help them as well as yourself). From there you might be able to get the information you need to coexist.
MTI and Til-Tek both make excellent 90* antennas. Last Mile Gear appears to have a 90* as well.