Looking for some advice on utilizing the split sector option of the epmp 3000. I have a epmp 3K with about 37 clients on it and at peak hours we are reaching 90-100 mbps, around 85% total frame usage. Wondering if setting up split sector function would benefit us? I read we would lose the mu-mimo, thoughts?
Split sector is for non-overlapping sectors. Are your sectors pointed in the same direction? MU-MIMO is more valuable I’d say in most cases. What channel bandwidth are you running? What’s your grouping like? Also, keep in mind that MU-MIMO doesn’t start really kicking in til about 93% frametime.
We have 3 sectors (e3K radios), north, west and east facing. 20mhz channel
Ah so not overlapping? I am curious if you are seeing grouping.
Sorry for late reply, my North facing sector is the busiest… just thought if I could spilt into smaller sectors could free up some airtime… unless I am misunderstanding.
Split sector is going to limit you to the capacity of the AP without MU-Mimo. Mu-Mimo will have greater throughput potential if the setup is correct.
So if I understand you correctly you currently have a 3k AP and I’m assuming it’s using the Cambium 3k Sector ? So the first thing you need to consider is, how spread out are the customers on this sector ?
Lets say that the customers on this sector are spread out pretty evenly across the sector’s coverage area and lets say it’s a 90° sector. So if you split that 90° right down the center with 45° sectors about 1/2 the customers are one 45 and half on the other 45 so that would be the perfect solution.
However, lets say that almost all the customers are over on one side of the sector’s coverage so now most all of your customers are on one 45 and the other 45 has none or only a couple. Now just splitting the 90° into two 45’s doesn’t really solve your problem.
So that’s the first thing you need to know. Were are all the current customers at and what are the expectations for growth in that direction.
So assuming your customers are spread out enough that splitting a sector down the middle will work well, now you face the 2nd challenge… if you are depending on MU the more narrow the sectors are the less MU you are going to have. So really when you get down to sub 60° sectors MU becomes not so useful and if 3000L was a better radio it would be the obvious solution.
However the 3000L lacks more than just MU.
- No Sync Over power
- No dynamic filtering
- 3000 is sensitive down to -92dbM vs 3000L down to -89 (3000L needs 2 or 3 better dBm to achieve the same MCS as 3000)
- No downlink beamsteering. The 3000 increases link budgets by 3 dB with downlink
- 3000 +32dBm transmit power 3000L +29dBm transmit power (is this due to the downlink beamsteering? I don’t know)
I have considered using a 3000 on very narrow Horns/Sectors and just connecting to 2 of its 4 rpsma connections. However there are a lot of unknowns when doing this and it gets more complicated if you have N clients it seems.
Then there is the option of connecting 2 2xMimo horns/sectors to a single 3000 radio (maybe this is what you are asking about here?) and have them pointing the same direction / completely overlapping. There are people in these forums that have done it, as far as I can glean from the posts / discussions it seems to work as expected though I’m still not convinced MU works exactly as good as it should.
All that said, if you are thinking about going with 2 x 3000Ls with 45° horns you will be getting zero MU and if you use a 3000 with 2x completely overlapping 45° horns if you get any MU at all it’s still more than you would have with the 3000L AND every other aspect should work better than 3000L and be far more reliable than 3000L.
I’m not sure if the “downlink beamsteering” will work but I guess even if it doesn’t you wasn’t going to get that with 3000L anyway.
Oh and downlink beamsteering is not the same thing as the little extra panel antenna you can buy for 2000 and 3000 that does “uplink” beamsteering (or Beam Forming depending on which manual you look at and beam forming and beamsteering may or may not be the same thing, depends on who you ask it seems).
Like Brubble said, it is possible but your actual gains on this will be from adding another AP instead of using split sector. If you need to add capacity to a sector, add another AP above or below, use GPS sync and move priority customers to the new AP.
Split sector is to reduce radio count on a low density location. You need the fiber port of the e3k but do not need the full capacity on a single sector type of arrangement, so you use one radio for N&S and another for E&W and only use dual polarity/feed sectors. This saves on radio count and keeps antenna cost down (though quad feed antennas are not really much more expensive).
Oh wow, thank you very much for the explanation/information. I am definitely ignorant on this subject and can not find any literature explaining the “split sector” option.
That was exactly what I was referring to.
Thank you for your reply, so if I add another 3000 with a 90 degree sector and put it below the existing one, the only way gps sync will work is that the existing AP/radio is not using gps sync already, correct?
no. All APs on a tower should be syncd.
enable gps either internal gps or cmm (packetflux cambium sync injector and a syncbox jr work great, does 4 radios per injector and can be daisy chained for more radios, one syncbox can sync as many radios as you can add) on all radios on the tower. Even if they are different channels, sync ensures that the APs are not talking over each other. This is very important if you are doubling up a sector as you would have to have a lot of vertical separation otherwise and will still be fighting self made interference.
Another side effect of having all of your APs in sync is your frame utilization will go down a bit due to the number of retransmissions that will no longer be needed.
I see, yes all 3 existing APs are gps sync… so to add another AP above or below I just need frequency room. And with them being syncd, should there be any vertical separation? Thank you for your help/insight
depending on your antennas, 3 to 6ft of vertical is good, you can get away with less and more wont hurt. Cheap antennas with bad f/b ratios and bad vertical lobes need more vertical space.
If you set your tilt angles correctly, the two radios can be on the same channel, even though that is not a great idea, it does work with the epmp radios and they must be in sync with both radio settings and sync source.