MA-ANT-25 connecting to MR-74

[Josiah]

Greetings,

I have 2 MA-ANT-25 and I'm wondering where do connect the horizontal and vertical cables? 

MR-74 has 2 ports for 5 ghz on top and 2 2.4ghz on bottom.

For one MA-ANT-25, does both of its vertical and horizontal go to both of the 5 ghz ports?

Or do I need to split them between between the 5ghz and 2.4 ghz?

Thanks

[ww]

https://community.meraki.com/t5/Wireless-LAN/MA-ANT-25-connection-to-an-AP-MR-74/m-p/19265#M3210

[Josiah]

Sadly that link does not answer my question,

I referred to the Horizontal and Vertical labeled cables that run out of the MA-ANT-25. 

Considering that I already have two of said MA-ANT-25, I believe this is the proper procedure:

Hang one MA-ANT-25 (L-ANT) to the left of the MR 74 and the other one (R-ANT) to the right.

With L-ANT, the H and V cables need to be split with one going to 5ghz and the other to 2.4ghz.

With R-ANT, the H and V cables are the opposite.

Example,

For L-ANT, H cable is going to 5ghz and V cable is going to 2.4gh. This means that for R-ANT, H cable is going to 2.4ghz and V cable is going to 5ghz.

If this is incorrect, please let me know.

Thanks

[PhilipDAth]

I bet @Nolan knows the answer.

[NolanHerring]

I think @PhilipDAth meant me, not whoever @Nolan is  😃

With the MR74, since there are two ports for 5GHz and two ports for 2.4GHz, you'll have to get two of the Meraki antenna since they do not sell a 4-lead antenna (Lord know's why).

On the MR74 there is nothing that indicates vertical or horizontal, so it has always been my conclusion that it doesn't matter when connecting the antenna cables. Just that the two antenna cables have to both go to either the 2.4GHz ports, or the 5GHz ports, do not mix them.

I also have not been able to find any information about the reason for why they label them vertical and horizontal, and if it did matter, I'm 100% confident that they would be shooting themselves in the foot because nobody pays attention to things like that. Especially since its not documented anywhere I can 'easily' find.

That being said, I'm going to add @MerakiDave so he can provide clarification. I feel for you on the confusion part, and feel that Meraki could add some clarification in their installation guide or the antenna box paper stating that it doesn't matter.

Again this is an educated assumption on my part since I've never seen anything otherwise.

TLDR - The antenna pigtails need to connect to the same radio and it doesn't matter which of the two ports for that radio you connect them to. Do not have one cable going to 2.4GHz and the other to 5GHz.

[MerakiDave]

Thanks @NolanHerring for looping me in.  @Josiah the MR74 has band-specific antenna ports, two 2.4GHz on one side of the AP and two 5GHz ports on the other side of the AP.  The AP only has labels for the band, not the polarization.  Each ANT-25 is a 2x2 antenna with one horizontal element and one vertical element.  It does not matter which pigtail cable (H or V) from the ANT-25 connects to which port on the AP.  So have 1H+1V go to either of the two 2.4GHz ports for one ANT-25, and then same thing for the 5GHz ports.  That is, there is no concept of left/right or H/V on the AP ports, the AP is just sedting 2 spatial streams, it's the antenna that determines the polarization.

Best to not mix the 2.4 and 5GHz ports across a single antenna.  Although you could physically do that (cross connect a pair of ANT-25 antennas across band-specific ports) and it wouldn't harm anything, you could unintentionally radiate 2.4GHz with only horizontal polarization and 5GHz with only vertical polarization (or vice-versa), and may not get optimal results. 

So I suggest to NOT do what you described above, that is, run H cables to 2.4 and V cables to 5, rather connect H and V from one antenna to the 2.4GHz ports, and H and V from the other antenna to the 5GHz ports.

It's unrelated, but I'll mention that on the MR84, all 4 ports are dual band and there is a diplexer in the AP to separate the 2.4 and 5GHz, and there too, you would be using 2 ANT-25 antennas, and with the same orientation to radiate 2H+2V out of the 4x4:4 AP.

[Josiah]

Howdy!

Thank you for taking the time.

If I am understanding correctly,  one ANT-25 will be broadcasting then on 5ghz and another will just be broadcasting on 2.4ghz?

Thanks!

[MerakiDave · Accepted solution]

Correct, you will end up with one ANT-25 connecting its H and V cables into the 2.4GHz ports on the AP, and another ANT-25 antenna connecting its H and V cables into the 5GHz ports.  

Doesn't sound like it applies here, but sometimes causes confusion, so in case others come across this thread... On an MR74, they can be different antenna models on the 2.4 and 5GHz ports.  For example, if you were to use an ANT-25 patch or ANT-27 sector antenna on the 5GHz ports to create a mesh backhaul link.  Imagine from a distant sports field back to a building, and then have ANT-20 omnis on the 2.4GHz ports to serve clients out in that area.  Even though these antennas are dual-band, you would really only be using one band for backhaul and one band for serving clients.

On an MR84 however, it's 4x4 and you should have both antennas be the same type, and aimed with the same orientation.  A common mistake is to have an MR84 on the side of a building with a pair of ANT-25 patch antennas, and aim them in different directions to increase coverage, but that's not the idea.  That just sends 2 spatial streams in one direction and 2 in the other, will have unintended consequences.

Sounds like you have an MR74 with a pair of ANT-25 patch antennas and they'll both be covering the same area with both bands.  But there too, don't aim them in different directions to increase coverage, you would end up aiming 2.4GHz in one direction and 5GHz in another, which could arguably increase the coverage area but likely not what you intended and it could introduce client issues.  

[GIdenJoe]

That can be a bit confusing if you also deal with Cisco AP's because some of them have the XOR radio enabling them to point to antennas in different direction because the extra radios is also set to 5 GHz and puts all it's spatial streams on one antenna for radio 0 and the other antenna for radio 1.

If you go to Cisco Live events you can see the setup like that.

[tkdas]

Hi All,

I am still not clear about the connectivity. Requirement is both Antenna  support both 2.4 & 5 Ghz  band simultaneously . We are using MR-74 with MA-ANT-25 Antenna in a warehouse environment. Please help if below physical connectivity is ok. Both the antennas are connected to  both 2.4 & 5 ghz. I see some post saying one antenna to be connected to two 2.4 ghz  radio in the AP & other antenna to be connected to two  5 ghz radio port.

Other post suggest  one antenna can be connected to both 2.4 & 5ghz radio at the same time.

-  will dual band with band steering work for RF clients when Antennas are connected as per  below diagram  ?

- Will we have any coverage /signal propagation issue ?

- What is the of  having two Antenna if they can not server both type of clients (2.4 & 5 ghz) simultaneously )

- I have a  location where I need to put  AP in the ceiling  & want two MA-ANT-25 antenna to propagate 2.4 & 5 ghz signal in both left & right direction.

MA-ANT-25 Antenna Physical Connectivity

[GIdenJoe]

Nope, that connection is wrong.
You have radio's that expect two spatially diverse antenna's to do 2x2.

By connecting the antennas that way you basically create two independent 1x1's and this will cause problems.
Connect one antenna to both 5GHz ports and the other to both 2.4GHz ports.

[tkdas]

Thanks for your quick  response.
Would appreciate if you can  explain a bit  more on what you have mentioned 'You have radio's that expect two spatially diverse antenna's to do 2x2.'

 'By connecting the antennas that way you basically create two independent 1x1's and this will cause problems'.

All together we have 2x2 radio.  2 * 2.4 +2* 5 ghz

Basically I am trying to cover some 70 mtr Aisle signal coverage by placing the Aisle  in the mddle (5 Mtr)  & want both 2.4 & 5ghz signal to propagate the  in both the direct tp cover all 70 mtr aisle   . APs will be mounted  in the ceiling. Other wise, I may have to  put twp APs in the Aisle to cover all 70 Mtr length, one at one end of the Aisle (north end ) & other end of the Aisle (south end). Do we have any other option ?

May be this needs a deeper understanding.

[GIdenJoe]

If your ceiling is only 70 meters long and putting that AP in the middle will create a 35m radius that needs coverage.
If the aisle itself is obstacle free you would have no problem reaching both ends using simple MA-ANT-20 antennas.

Using the MA-ANT25 on hight ceiling is also a viable option but 5 meters is not really that high.  In that case you'd be better off hanging it on the wall pointing down the aisle however you need an actual wall and then you'd have the entire 70 meters to cover.  And the MA-ANT25 is IMO a little too wide and too little gain to do this.  In that case the MA-ANT27 would have been better since that one has higher gain and narrower beam.

The reason to discourage the antennas in different directions has to do with the fact that you would get strange results.  The Meraki AP has 2 radio's, one for 2.4 and one for 5.  So theoretically you could have a 2.4 cell in one direction and 5 in another but that does not make sense.  Also trying to extend your cell by cross connection your antennes will have weird results since the AP will try to to spatial multiplexing or ratio combining to your wifi client.  However if both antennas are pointed in different direction that will yield in possible destructive signales instead of constructive.

So if it's only one aisle. Stick to the center and use omni's pointed vertically.  Make sure the antennas have complete clearance.  If you have multiple aisles then you'd normally stagger the AP's, so one at 1/3rd of the way in one row, and the next row one at 2/3rds.

That depends on the situation though.

[tkdas]

Thanks for your explanation. We  should not cross connect  the radio to propagate both frequency signal (2.4 & 5 GHz)  in both the direction  from both Antenna for reason you have explained.  We  need to connect the Antenna as per recommendation ( one Antenna to 2.4 ghz  radio and other to 5 ghz)

We have the option of only MR 74 & MA-ANT-25 Antenna . There are multiple aisles . Aisle length is 70 mtr and  the rack height is 12  mtr. There are several aisles . We can mount AP in the celing above 12.5 mtr  as there is no wall to mount the in the wall side . Can we place the AP in the middle with both 2.4 & 5 ghz antenna direction in one side    as per below heat meat shown  (image 1)  or it would more prudent to place the beginning (north)   & end(south) of the in the alternate aisle .  Or we need put all MR-74-ANT-25 in one side (image 2).  

[GIdenJoe]

I see you have Ekahau and that the ceiling height is much higher than the 5 meter originally given.

I'd encourage you to first experiment with the MA-ANT-25 pointing straight down at 1/3rd of an aisle and see if it covers the entire aisle or not.  I do recommend using the offset feature to subtract some 5 dB from your "measured" value.

Then you could do a staggered pattern in your aisles 1/3rd, 2/3rds.

[tkdas]

Thank you very much !

If I understand correctly ,  below staggered approach I should try . Both the Antenna ( 2.4 & 5 ghz) directing/facing  should be  towards  2/3 area of approx. 46 mtr ( marked with Arrow). 1/3 area approx. 24 mtr would be automatically covered with both 2.4 & 5 ghz  even though  both the  radio band are not direced /faced/oriented towards 1/3 area. Of course , we need to try/test.

[GIdenJoe]

Yeah but I mean downwards pointing antenna.
Normally we do staggered when it's open so there is some distance between the AP's.  But if the aisles diminish the signal enough it's not a real requirement.
But as said before, try simulating the AP at the correct height with the antenna pointing down and see if the signal reaches all the way to the end of the aisle.

If that doesn't work but the aisles weaken the signal enough, you could try in the middle pointing down and if that is not enough try 1/3 closer to the wall and then use the AP's in the open area for roaming.

That's one of the big plusses of having software like ekahau, you can try all 3 scenario's and see which is best.

[skhader]

Hello,

This question also apply to me and I want to make sure I read it correctly.  Instead of MR74, I have the MR84 (4x4).  to get the best coverage do I connect both of the One ANT-25 antenna pigtail cables to the top of the MR84 and another ANT-25 pigtail cables to the bottom of the MR84?  Thanks,

[tkdas]

one Antenna for 5 ghz & other Antenna for 2.4 ghz coverage

[Bruce]

Yep, connect one ANT-25 antenna to both the top ports, and another ANT-25 antenna to both the bottom ports. The difference with the MR84 (being a 4x4 access point) is that all the ports are dual band (so both 2.4GHz and 5GHz) and you want to have the antennas covering the same area so that all the smarts of 802.11ac Wave 2 work as expected.