Hello,
I was looking at the spec sheets for the 2.4Ghz Epmp sector antennas and it says they are dual slant +/- 45 degree antennas. Is this correct?
Are Integrated units dual slant as well?
Thanks
Going off memory, yes and no. If I remember correctly the sector is slant but the integrated unit is H/V, any loss is made up for with Cambium Magic dust. Cambium will be able to confirm this.
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Just trying to figure out why you would do this, if not slant on both sides.
Hopefully they will explain!
I was told that the integrated units were dual slant as well. I know the spec sheet doesn't show this but why would they not do this. Should we be mounting our integrated sm's at an angle? :)
Hi All,
Ben is correct. The 2.4 GHz sector antenna is a dual slant and the integrated patch antenna on the SM is H/V. For the ePMP, there is no performance difference between a dual slant antenna communicating with a H/V antenna and two H/V antennas. Please see the attached explanation. It is technical, but I think explains the situation.
Thanks,
Sriram
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Wow, somebody really needs to dumb that paper down for me. After reading that, all I can say is that cambium has some people too smart for their own good working for them. That's probably why they have the best wireless gear.
What's the downside to using a non slanted sector, potential for more noise at the AP?
Just wanted to bump this thread. I was still looking for an answer to this question "What's the downside to using a non slanted sector, potential for more noise at the AP?"
Also, I read that the epmp line supports mimo matrix A. Does the slanted sector have any affect on the performance of mimo A?
That's really the only difference - a slightly difference noise floor. On one hand you'll hear more in vpol from customer routers but you'll hear less being in hpol than either slant. IIRC you're hearing 12.5* different with linear than slant.
Hi Chris,
In tests we have undertook, there is no difference between slant and H and V with regards to MIMO-A and MIMO-B performance.
Dan
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Magic Dust!!!
Ceci and I are laughing pretty hard right now...
I ran a difinitive test today.
From atop a water tank I had an ePmp 2.4 AP with a 14Db Linier Omni from KPPerformance. I had 2 customers on it and a crew testing at a third.
Location A : Line of site, 1/8th mile from tower (formerly -44 on Canopy 900). I arrived at a -53 and about 90+ quality capacity on ePmp.
Location B: Non line of site to tower, 1/4 mile from tower, (Formerly -45 on Canopy 900). I got a -60 and a wopping 30-50% quality and capacity.
Location C: rougly 2 miles from tower, with a parabolic Dish, (Formerly -60 on Canopy 900). They were not able to connect to the tower, but saw it in a scan at about -87.
I swapped the V/H antenna out for a 45 dual slant Omni from KP. It was 11Db so I anticipated a 3Db drop.. The results were VERY dissapointing.
Location A: Now a -60 with 60% quality and Capacity.
LocationB: Now ranging from a -74 to a -80 with hardly any quality or capacity.
Location C: no longer seeing the AP in a scan.
Needless to say I'm seriously dissapointed with the $700 antenna I just purchased and not at all impressed with ePmp...
Has onyone else had better luck??
I've gone back and forth between antenna manufacturers and have found that I prefer the recommended Cambium antennas over 3rd party antennas. If I were you I'd test with the recommended Cambium 90deg dual-slant antenna (P/N: C024900D004A) and play around with up/downtilt with a handful of subcribers in your target coverage area and see what you get. There are a few special use cases where I might use an omni, but if at all possible, use a sector.
Also, I assume you're using the integrated 2.4 ePMP units. You might want to try a reflector dish with one of these or stall your deployment until the Force200 2.4 units come out, which was supposed to be in July but....here we are in August and still no radios :-(
I'm already using KP dish kits with my far away install. I need an omni for one simple reason. Cost... We have several towers where population density is such that we only have a dozen or so subs. ePmp was going to be an alternative to Ubnt 2.4 but so far Ive been much happier with UBNT in this configuration. (Yes, that would have tasted nasty if I would have said it out-loud)
I'm curious if ePmp was marketed as a non/near line of site product in 2.4 because it's worse than 100 series 2.4 IMHO...
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Comparing 900 to 2.4 is never going to be a fair test. 900 mhz by nature will carry further than the 2.4 with obstruction. 2nd your trying this with omnis, your snr will suck no matter the manufacturer. The advantage with dual slant most of the time is improved mimo performance when dealing with obstruction, liener will show better rssi under LOS conditions. Also a quick understanding of how slant and liner mix, if both antennas are 14 db, the slant signals will show 3db weaker, however in poor signal conditions youll typically see much butter chain power match. Ive seen plenty of liener shots have miss matches as far as 12 point, resulting in the cpe showing -65 and running in mimoA mode, hurting performance over all. With dual slant antennas on one end, youll likely see a near balance resulting in mimo B modes being used and significantly improved performance in non line of site conditions. If you read up on antenna theory, youll find some nice write ups. I believe comscope has a few good ones (they make lte antennas for sprint, ATT ect.) Regardless of who you choose for your access points, the 2.4 will always fall very short to 900 when comparing penitration. In low density deployment, the ubnt gear works OK, but under loading and poor signaling conditions, the Cambium radios have always performed better for us. However, we install with 4 sectors and in AB reuse, with the recommended duel slant. Aside from pannels with only 2 or 3 subscribers and no neighboring APs, I’ve let to see ubnt gear out do the Cambium. In light loading conditions, I see the argument with the lower latency. The biggest advantages Cambium has is the GPS sync, and air time share instead of bandwidth share. Ubnt has a well known problem of one bad cpe taking the performance and experience of all subscribers on that panel, while weak signal do reduce cambiums performance, one subscriber can’t kill the experience of the other subscribers so be careful with your rx modulations and ccqs on the ubnt gear. Ubnt has its place and works well in some conditions, our experience has been the Cambium over all exceeded ubnt when installed as Cambium recommends.
@Isaac Uban wrote:Has onyone else had better luck??
The ePMP AP that I'm connected to at home, it's ~4 KM away (2.5 miles) and a 'farily' clear line of site. EXCEPT that I'm shooting right through the house & the Poplar trees across the street. After that, the terrain drops off so the rest of the 3.8KM is pretty clear.
-60 signal, quality is 80-90% and I've got my SM set to a 10 Mbit plan and I get 10 Mbit all the time. This is right through town, and my SM can hear a crapload of routers, but seems to do fine with interference. So, for me - I'm pretty impressed with ePMP. :)
@Eric Ozrelic wrote:
I've gone back and forth between antenna manufacturers and have found that I prefer the recommended Cambium antennas over 3rd party antennas. If I were you I'd test with the recommended Cambium 90deg dual-slant antenna (P/N: C024900D004A) and play around with up/downtilt with a handful of subcribers in your target coverage area and see what you get. There are a few special use cases where I might use an omni, but if at all possible, use a sector.
Also, I assume you're using the integrated 2.4 ePMP units. You might want to try a reflector dish with one of these or stall your deployment until the Force200 2.4 units come out, which was supposed to be in July but....here we are in August and still no radios :-(
Hi Eric,
The Force 200's availabllity has been delayed by about 4 weeks due to a minor issue we will have to resolve in the factory. Aplogies for the delay. We are workng hard to get it out as soon as possible.
Thanks,
Sriram
@Isaac Uban wrote:
I'm already using KP dish kits with my far away install. I need an omni for one simple reason. Cost... We have several towers where population density is such that we only have a dozen or so subs. ePmp was going to be an alternative to Ubnt 2.4 but so far Ive been much happier with UBNT in this configuration. (Yes, that would have tasted nasty if I would have said it out-loud)
I'm curious if ePmp was marketed as a non/near line of site product in 2.4 because it's worse than 100 series 2.4 IMHO...
Hi Isaac,
The 100 series and ePMP are two different beasts or rather two different technologies. So its not a fair comparison. There are a lot more differences between the two platforms than similarities (one being both are 2.4 GHz).
I'm sorry that you are having so much trouble with your ePMP installation. Have you contacted our support staff yet for help with this? They can be reached 24/7 at http://www.cambiumnetworks.com/support/contact-support.
Thanks,
Sriram