Meraki MR74/76 antenna polarization settings

SOLVED
Eugenijus
Conversationalist

Meraki MR74/76 antenna polarization settings

Hi,

 

We have multiple MR74 and MR76 installed in our warehouse. All them have MA-ANT-20 omni-directional antennas installed. Now APs are mounted to ceilings (horizontally), but I read that vertical install is better for these antennas. I have a few questions:

1. If we change AP orientation to vertical, with 5GHz ports/antennas pointing downwards, will it affect 2.4GHz signal?

2. How can I select polarization "Half power beamwidth / vertical: 45° "? I can select what antennas are installed for each AP, but cannot find where to change polarization settings?

3. We plan to disable 2.4GHz band broadcast. Is there a cups to cover 2.4GHz antenna ports, or do I need to have antennas installed to prevent damage to AP?

 

Thanks in advance.

1 ACCEPTED SOLUTION
MerakiDave
Meraki Employee

Hi @Eugenijus and welcome to the Meraki Community.  The polarization is a characteristic of the physical antennas themselves, so that is not something that can be configured or adjusted.  The setting in Dashboard allows you to change the antenna type, depending on what is actually connected to the AP, such as the ANT-20 omnis or an ANT-25 patch for example.  

 

The ANT-20 omni has vertical polarization and the radiation pattern is the typical "donut" shape, so if the AP is mounted on a wall or pole and those antennas have vertical orientation, then your "donut" is omnidirectional in the horizontal direction.  Kind of like this:

MerakiDave_0-1644543622173.png

 

If the APs are now mounted flat to a ceiling, then your "donut" pattern is turned sideways, and much of the RF signal is being propagated up/down and sideways as opposed to all around like in the image above.  There isn't a way to adjust that, the antenna polarization is fixed and part of the antenna.  

 

Depending on the coverage area and number of APs, this may or may not work ok, you will have to test and take measurements.  If you associate to any SSID and bring up the local status page by pointing a browser to ap.meraki.com you will see your connection and signal strength and can walk around and do your own basic mini site survey.  Depending on ceiling height and distance, it may end up working much better with ANT-25 patch antennas which have articulating arms and can be aimed at the coverage areas. 

 

On the other question, yes, if you are not going to use the 2.4GHz ports on an MR74 or MR76 and the 2.4GHz radios are going to be disabled, you don't need antennas on those ports and the 2.4GHz ports need to be protected with any 3rd party weatherproof "N" type dust cap. The plastic caps that come with the AP are just for protection during shipping, not for weatherproofing.  Note that it it is an MR84 or MR86, those are 4x4 APs and all 4 ports are dual band and will always be in use.  Sounds like you have 74/76 so that's fine to disable the 2.4GHz radios and not have antennas on the 2.4GHz ports.

 

More info in the antenna FAQ as well. 

https://documentation.meraki.com/MR/Other_Topics/Frequently_Asked_Questions_regarding_Cisco_Meraki_A... 

 

Hope that helps!

 

View solution in original post

2 REPLIES 2
MerakiDave
Meraki Employee

Hi @Eugenijus and welcome to the Meraki Community.  The polarization is a characteristic of the physical antennas themselves, so that is not something that can be configured or adjusted.  The setting in Dashboard allows you to change the antenna type, depending on what is actually connected to the AP, such as the ANT-20 omnis or an ANT-25 patch for example.  

 

The ANT-20 omni has vertical polarization and the radiation pattern is the typical "donut" shape, so if the AP is mounted on a wall or pole and those antennas have vertical orientation, then your "donut" is omnidirectional in the horizontal direction.  Kind of like this:

MerakiDave_0-1644543622173.png

 

If the APs are now mounted flat to a ceiling, then your "donut" pattern is turned sideways, and much of the RF signal is being propagated up/down and sideways as opposed to all around like in the image above.  There isn't a way to adjust that, the antenna polarization is fixed and part of the antenna.  

 

Depending on the coverage area and number of APs, this may or may not work ok, you will have to test and take measurements.  If you associate to any SSID and bring up the local status page by pointing a browser to ap.meraki.com you will see your connection and signal strength and can walk around and do your own basic mini site survey.  Depending on ceiling height and distance, it may end up working much better with ANT-25 patch antennas which have articulating arms and can be aimed at the coverage areas. 

 

On the other question, yes, if you are not going to use the 2.4GHz ports on an MR74 or MR76 and the 2.4GHz radios are going to be disabled, you don't need antennas on those ports and the 2.4GHz ports need to be protected with any 3rd party weatherproof "N" type dust cap. The plastic caps that come with the AP are just for protection during shipping, not for weatherproofing.  Note that it it is an MR84 or MR86, those are 4x4 APs and all 4 ports are dual band and will always be in use.  Sounds like you have 74/76 so that's fine to disable the 2.4GHz radios and not have antennas on the 2.4GHz ports.

 

More info in the antenna FAQ as well. 

https://documentation.meraki.com/MR/Other_Topics/Frequently_Asked_Questions_regarding_Cisco_Meraki_A... 

 

Hope that helps!

 

Eugenijus
Conversationalist

Hi Dave,

 

Thanks for the deep explanation. That information is very useful. I'll check signal strength on ap.meraki.com with APs mounted flat as they are now and then change couple of them to vertical orientation and compare signal strength again. This will give a better view of coverage per AP.

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