Understanding Antennae Radiation Patterns

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Understanding Antennae Radiation Patterns

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Understanding Antennae Radiation Patterns
Understanding Antennae Radiation Patterns
2022-07-27 07:02:06 - last edited 2022-08-02 03:15:19
Model: EAP615-Wall  
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Hi

 

Can anyone direct me to any information on how to understand radiations patterns that are provided for Omada APs.

 

Any help would be appreciated... I would like to know how the APs will transmit wifi signal before purchasing.

 

Thanks

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Re:Understanding Antennae Radiation Patterns-Solution
2022-07-27 18:08:27 - last edited 2022-08-02 03:15:19

  @K18_LDP 

 

Hey

 

I will try to explain these for you, hopefully in the easiest way possible.   Just to clarify first, these tend not to change between vendors, the patterns are usually 99% the same for similiar APs, by that I mean a Ceiling Mounted AP from Cisco, will be very similiar to one from Juniper, TP Link, HP etc..

 

The main difference in patterns are found between different AP types, this is related to the arrangement of the antenna inside the device.   In short patterns relate to the arrangement of antenna and how it directs the signal.

 

Lets look at below for an example.

 

 

 

Look at the first picture (one on left) its the pattern of the AP if viewed straight on (looking across the device).   You will notice the pattern in blue around radiates around the device fairly evenly, except at the bottom where it dies to nothing.   That is by design as the bottom will likely be mounted to the wall or ceiling and there is no benefit to having good signal wasted by being shot into the brick wall.  By designing the antenna to send as little signal into the wall, its offers a bit more to send a better direction.   Result is that antenna setup offers little to no signal above the ceiling (as by design) instead pushing it out fairly evenly on the AP face, the bit that will point to your clients.   My engineers call these APs "claymores" as you face them to the users, which hopefully explains the pattern :)

 

The second picture is the same as first, on a different theta.. dont worry about that.. just ignore

 

The 3rd picture is the signal from top down, basically it spreads evenly in all directions from the AP.

 

The normal router you have at home with 2 / 3 or 4 stick up antenna (these are called omnidirectional) have a different pattern, they blast evenly in all directions from the antenna.  So if you are beside a wall, 50% of what it transmit goes into the brick.  These by design are best situated in an open area like the centre of a room or similiar. 

 

 

In summary, the pattern of an AP is more for professsional locating of the AP and nothing else.  

 

Can I ask what you are looking to discover from this?   Any reason behind the question?

 

Hope that helps.

 

 

 

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Re:Understanding Antennae Radiation Patterns
2022-07-27 13:52:42

  @K18_LDP 

 

They are similiar in transmit pattern to any other ceiling mounted AP.

 

If you need the exact patterns they are on the document below around page 17 onwards

 

https://static.tp-link.com/2020/202010/20201019/EAP%20Datasheet.pdf

 

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Re:Understanding Antennae Radiation Patterns
2022-07-27 17:10:25

  @Philbert 

 

I have seen the patterns on the document... what I'm having difficulty in is actually understanding what these patterns mean in practical terms

 

Thanks

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Re:Understanding Antennae Radiation Patterns-Solution
2022-07-27 18:08:27 - last edited 2022-08-02 03:15:19

  @K18_LDP 

 

Hey

 

I will try to explain these for you, hopefully in the easiest way possible.   Just to clarify first, these tend not to change between vendors, the patterns are usually 99% the same for similiar APs, by that I mean a Ceiling Mounted AP from Cisco, will be very similiar to one from Juniper, TP Link, HP etc..

 

The main difference in patterns are found between different AP types, this is related to the arrangement of the antenna inside the device.   In short patterns relate to the arrangement of antenna and how it directs the signal.

 

Lets look at below for an example.

 

 

 

Look at the first picture (one on left) its the pattern of the AP if viewed straight on (looking across the device).   You will notice the pattern in blue around radiates around the device fairly evenly, except at the bottom where it dies to nothing.   That is by design as the bottom will likely be mounted to the wall or ceiling and there is no benefit to having good signal wasted by being shot into the brick wall.  By designing the antenna to send as little signal into the wall, its offers a bit more to send a better direction.   Result is that antenna setup offers little to no signal above the ceiling (as by design) instead pushing it out fairly evenly on the AP face, the bit that will point to your clients.   My engineers call these APs "claymores" as you face them to the users, which hopefully explains the pattern :)

 

The second picture is the same as first, on a different theta.. dont worry about that.. just ignore

 

The 3rd picture is the signal from top down, basically it spreads evenly in all directions from the AP.

 

The normal router you have at home with 2 / 3 or 4 stick up antenna (these are called omnidirectional) have a different pattern, they blast evenly in all directions from the antenna.  So if you are beside a wall, 50% of what it transmit goes into the brick.  These by design are best situated in an open area like the centre of a room or similiar. 

 

 

In summary, the pattern of an AP is more for professsional locating of the AP and nothing else.  

 

Can I ask what you are looking to discover from this?   Any reason behind the question?

 

Hope that helps.

 

 

 

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Re:Understanding Antennae Radiation Patterns
2022-07-27 19:02:57

  @Philbert 

 

Thank you soooo much for your reply... I think I'm able to understand the patterns now.

 

The reason for my question is that I'm trying to work out what types of AP I can/Should install in my property.  I have added the floor plans above. The blue dots are where I have POE ethernet connections that I can use for the APs.

 

With the patterns I can decide which AP will work for me.

 

My current thoughts are:

 

1. First floor only one AP - EAP660 in hallway ceiling using the blue dot near the middle of the floor (will have a spare ethernet connection if needed)

2. Ground floor - in hallway use another eap660 but installed in wall facing in towards the house( can't install in ceiling here)

 

Thinking of in wall EAP615s or eap650 walls(when released)  for the other two APs on the ground floor.

 

Thoughts... ?

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Re:Understanding Antennae Radiation Patterns
2022-07-28 15:44:48 - last edited 2022-07-28 15:47:12

  @K18_LDP 

 

Hey

 

The EAP660 ceiling/wall mount range sounds like the best for you, in honesty its usually the default go to for 99% of installations, rarely do you need to change away from that syle of AP.

 

Couple thoughts on this... 

 

Depending on how big your house is and its construction, you might need to do a heatmap to find coverage.   Something like netspotapp or similiar will work, basically you place any AP in the centre and walk around marking as you go, this can be any AP you have sitting around as its only for detecting of signals.  The app records the loss and recommends placement of APs based on how the signal reacts to your construction (reflection, loss, absorbsion etc).    As a general rule of thumb my engineers tend to go 1 AP per 500sq foot of house, remember that is based on UK where its Brick all round, you may be different.   If you in the 2000sq ft or bigger house, you need to heat map this as wall, ceilings etc will all affect it.  

 

Have you any measurements you could mark on the picture?  Also note any major (non stud) walls, chimney, stairs etc.

 

Im also concerned for the L shape of your first floor, the lower part (skinnier section) may not get much signal from an AP located central in the top half.  I would guess you need 2x APs on that top floor.    You might get away with 1x downstairs as the signal will be directed that way.

 

Also the wall APs.. bear in mind its for a single room only, they are very directed signal and only work in that one wall facing direction.   If using them expect to have one in each room, they are designed for hotel rooms / dorms etc.  

 

 

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Re:Understanding Antennae Radiation Patterns
2022-08-02 21:02:59

  @Philbert 

 

Thanks for the response!

 

 

 

I've added a red line which is 8.6m wide. The brown lines are where internally there used to be external walls (house has been extended)

 

I am in the UK and house was built in 1960s so mainly brick construction. 

 

I think I will do EAP660 in all the places where I have blue dots (ie 2 upstairs and 3 downstairs)

 

The thin area of the upstairs hopefully will ve covered by an eap660 downstairs next to the garage ( the blue dot on the left side). The area upstairs is a spare room so not critical for coverage.

 

The reason I was looking at in wall APs was because I need more ethernet ports in these two rooms. The EAP660 only had one POE port in and no ports downstream which isn't great tbh... Will probably have to use a switch in these two rooms instead unless you know of another solution...?

 

Was hoping some of the ceiling APs would have downstream ethernet ports but can't find any. The upcoming eap690e doesn't look like it will either 

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