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WHT

join:2010-03-26
Rosston, TX
kudos:5
reply to wirelessdog

Re: Shield kits for Ubiquiti?

said by wirelessdog:

Somebody explain to me how this cluster works with all the radios in the same band and each non-overlapping frequency is used twice.

Easy....

1) All the transmitters are synchronized, so there isn't any receiver interference.

2) Adjacent radios not on same channel, so one radio won't be hearing any CPE on that adjacent channel.

3) Beamwidth of every third AP is such that they AP will only hear it's own set of CPEs.

Now what happens when there is any interference just outside of any one radio's beamwidth that is sufficiently strong enough to cause a problem? This is what the external shields do, they tighten the beamwidth.

Added...
said by wirelessdog:

NO Shields required LOL

BTW, you don't need shields to make that work. Unless you have uncontrollable third-party interference where shields have been shown to help.

OHSrob

join:2011-06-08

3 edits
reply to WHT
said by WHT:

said by OHSrob:

But they are of no use to me anyways since I plan my deployment's.

You are fortunate that your competition will work with you on mitigating the interference they are causing you.

They do not co-ordinate with me, I deal with over 10 different wisp's in my coverage area all using 20mhz channel's.

One waveon wisp, three canopy providers, two using mikrotik, three ubiquiti (two airmax) and one tranzeo wisp.

One of my 2ghz sectors picks up over 40 access points from various wisp's. (I have line of sight for about 50km from the sector)

I simply find the most clear part of the radio spectrum and size my channel and amount of equipment I put up accordingly. I also keep the amount of equipment I put up to just the minimum that I need.

I avoided a deployment of 900mhz for over two year's because I was not able to find a low noise suitable spot until only recently where I found a spot that I could not hear canopy on horizontal. I noise test from the ground before I even consider building a tower or hanging equipment.

I take advantage of large groups of trees and geographical isolation to limit self interference. I also only deploy 2.4ghz in very specific situations and at most only two 2.4ghz sectors per tower. (The majority being only one sector deployed)

None of my equipment has a transmit power higher then 24dbm and this is only on my macrocell's.

My Microcell's are all below 10dbm same with all my short backhaul link's.

I maintain the minimum transmit power required to maintain at a 3/4 64qam rate to my client's. I also ensure that no client needs more then at most one or two re-transmit's.

Also to prevent signal overload the best thing I have found is to try to offset sectors both horizontally and vertically with sufficient space to prevent them from hearing each other too loud.

This way I don't suffer from the increased ping and jitter people post about on the Ubiquiti forum that use GPS sync complain about.

My customer's can expect their ping to not vary more than 5ms or so 99% of the time. I do my best to ensure that all packet's are delivered on the first transmit to ensure the most free radio time. My network is also packetloss free even to my weakest customer that is something none of my competitors in my area can say about their networks.

said by WHT:

said by OHSrob:

But they are of no use to me anyways since I plan my deployment's.

You are fortunate that your competition will work with you on mitigating the interference they are causing you.

They do not co-ordinate with me, I deal with over 10 different wisp's in my coverage area all using 20mhz channel's.

One waveon wisp, three canopy providers, two using mikrotik, three ubiquiti (two airmax) and one tranzeo wisp.

One of my 2ghz sectors picks up over 40 access points from various wisp's. (I have line of sight for about 50km from the sector)

I simply find the most clear part of the radio spectrum and size my channel and amount of equipment I put up accordingly. I also keep the amount of equipment I put up to just the minimum that I need.

I avoided a deployment of 900mhz for over two year's because I was not able to find a low noise suitable spot until only recently where I found a spot that I could not hear canopy on horizontal. I noise test from the ground before I even consider building a tower or hanging equipment.

I take advantage of large groups of trees and geographical isolation to limit self interference. I also only deploy 2.4ghz in very specific situations and at most only two 2.4ghz sectors per tower. (The majority being only one sector deployed)

None of my equipment has a transmit power higher then 24dbm and this is only on my macrocell's.

My Microcell's are all below 10dbm same with all my short backhaul link's.

I maintain the minimum transmit power required to maintain at a 3/4 64qam rate to my client's. I also ensure that no client needs more then at most one or two re-transmit's.

Also to prevent signal overload the best thing I have found is to try to offset sectors both horizontally and vertically with sufficient space to prevent them from hearing each other too loud.

This way I don't suffer from the increased ping and jitter people post about on the Ubiquiti forum that use GPS sync complain about.

My customer's can expect their ping to not vary more than 5ms or so 99% of the time. I do my best to ensure that all packet's are delivered on the first transmit to ensure the most free radio time. My network is also packetloss free even to my weakest customer that is something none of my competitors in my area can say about their networks.

said by wirelessdog:

Sometimes the truth hurts.

Somebody explain to me how this cluster works with all the radios in the same band and each non-overlapping frequency is used twice.

NO Shields required LOL

When you don't have equipment on the same tower transmitting at the same time another device is receiving you cannot suffer from RF signal overload.

Proper GPS sync is nice, Canopy got it right first try.

said by Newbie:

"FYI wirelessdog, rf armor is just for people who cannot plan their deployments properly."

This is hands down one of the most ignorant blanket statements I have ever read on these forums..... And that says something!

Sorry but your right there is one instance where I would consider using them.

If I was co-locating with another wisp on the same tower or within 800 meters of my tower using the same band as me.
Expand your moderator at work


WHT

join:2010-03-26
Rosston, TX
kudos:5

Re: Shield kits for Ubiquiti?

Shield kits work to point some people don't bother with GPS.
Expand your moderator at work


WVNet

@lsnetworks.net

Re: Shield kits for Ubiquiti?

I find the mechanical benefits of the shields almost as useful as the RF shielding. With mountaintop towers at 7000 or 8000ft they offer protection from ice damage, contain the heat of the radio to protect from low temps, and offer a grounded metal shield around the radio, reducing the chance of lightning damage.

We use RFarmor, and he's been building them long enough to start making some good mechanical improvements to his designs.

raytaylor

join:2009-07-28
kudos:1
reply to wirelessdog
said by wirelessdog:

Sometimes the truth hurts.

Somebody explain to me how this cluster works with all the radios in the same band and each non-overlapping frequency is used twice.

NO Shields required LOL

Thats because the little triangle pointy thing on top is the GPS reciever. Canopy use gps timings.

I was just given an AP cluster like this with 7 AP's (6 for 360 coverage), two gps timing controllers (with the triangular antennas) and 50 client radios+reflector dishes

The instruction manuals say to have them on non-overlapping frequencies with the gps timing enabled.

They dont need shield kits because the timing is set up so that all AP's tramsmit at the same time - therefore one ap on the opposite side of the cluster wont be transmitting while another is recieving and therefore the self interference is removed.


WHT

join:2010-03-26
Rosston, TX
kudos:5
You still non-overlapping channels to prevent CPE interference at the AP.

Say if you had three sectors pointed N, SE and SW. A client off to the NE or E and associated with the N AP, would be seen by both the N and SE AP. The SE AP would see it as noise.

wolfcreek

join:2003-12-02
Pagosa Springs, CO

4 edits

1 recommendation

reply to OHSrob
That is one of the dumbest statements i have heard on these forums
AP shields lower co-location interference, interference from reflections and competitors. It also helps limit RF leakage from the antenna and AP which all plastic cased and many metal cased AP's from many other brands have. Trango and others offered AP shields ten years ago because they are a good idea. I have seen narrow beam Cell sectors with shields as well and I think Verizon and such know what they are doing.

When using DFS channels shields can help prevent weak radar or false DFS hits changing your channels or shutting down an AP

AP shields also help prevent installers from connecting to a weaker side lobe as we find the side lobes disappear with the shields on

One other benefit is that they restrict the beam width of the sector and prevent unintended interference with our other sites that are not geographically shielded from one another.

Licensed links use drum dishes that while one function is to allow a front cover the other function reduces side lobes transmitted and reduces side lobe interference from the sides and back that is received. I guess Radiowaves put those on there because they do not know how to do RF.

We have over 150 Ubiquiti access points deployed and everyone of them gets an AP shield. I will agree that Ubiquiti GPS is flawed and a disappointment. However we are outperforming the Canopy and wimax competitors with Ubiquiti and offering higher speeds and customer satisfaction for less cost.

AP shields are part of good RF management and I hope people
are not falsely led to believing they are a not a good idea. The canopy array would probably have better performance with shields not worse.

OHSrob

join:2011-06-08
said by wolfcreek:

That is one of the dumbest statements i have heard on these forums

AP shields lower co-location interference, interference from reflections and competitors. It also helps limit RF leakage from the antenna and AP which all plastic cased and many metal cased AP's from many other brands have. Trango and others offered AP shields ten years ago because they are a good idea. I have seen narrow beam Cell sectors with shields as well and I think Verizon and such know what they are doing.

I have yet to test the sector version. But the gear is good enough to not need them.Signal overload is the only really big problem you would have without them.

said by wolfcreek:

When using DFS channels shields can help prevent weak radar or false DFS hits changing your channels or shutting down an AP

I try to keep the DFS frequency's limited to under 2KM I also use the lowest transmit power I require for a link.

said by wolfcreek:

AP shields also help prevent installers from connecting to a weaker side lobe as we find the side lobes disappear with the shields on

One other benefit is that they restrict the beam width of the sector and prevent unintended interference with our other sites that are not geographically shielded from one another.

I have not tested the sector version. I kind of rigged up a crude version at the previous wisp I worked for. It worked pretty well at lowering noise at a site we co-located with another wisp

There was not enough radio spectrum for both wisp's to operate at the same time on that tower.

In my testing with the rocket dish version seems to need a higher SNR to maintain the 64qam rates with the RF armor on a rocket M5.

said by wolfcreek:

Licensed links use drum dishes that while one function is to allow a front cover the other function reduces side lobes transmitted and reduces side lobe interference from the sides and back that is received. I guess Radiowaves put those on there because they do not know how to do RF.

I have seen a few decommissioned TDM T1 and T3 microwave backhauls antennas. They all had some Foam inside on the inside of the drum part. This absorbs RF and prevents it from bouncing back.

said by wolfcreek:

We have over 150 Ubiquiti access points deployed and everyone of them gets an AP shield. I will agree that Ubiquiti GPS is flawed and a disappointment. However we are outperforming the Canopy and wimax competitors with Ubiquiti and offering higher speeds and customer satisfaction for less cost.

I have many access point's deployed.But I have not used ubiquity’s GPS sync but from what I have read people don't seem too pleased with it. I am sure any remaining issues will one day be fixed with software update.


WHT

join:2010-03-26
Rosston, TX
kudos:5
said by OHSrob:

But the gear is good enough to not need them.Signal overload is the only really big problem you would have without them.

First, it has been clearly demonstrated the shields prevent interference from another closely mounted radio.

Second, it reduces the AP from seeing a client that is not associated with that AP.