Antenna height in 4G, 5G NSA and 5G SA sites

Dear Experts.

4G operator is planning for 5G sites.
5G sites will be co located with existing 4G sites.
5G will be in 3 Ghz band.

Query: Height of 5G antenna should be same as 4G antenna?
Or 5G antenna height can be less than 4G antenna height?
What will be the ideal scenario?

1 Like

SA or NSA?

If NSA then try to make at same height.

If SA then definitely should be on lesser height than 4G!

What about Azimuth, Tilt…?

Any specific reason why SA at less height?

In my network NSA & LTE are having same Height and Azimuth.

I think because on NSA you are using LTE to be redirected to 5G so they need to have the same coverage if not you may have gap.

SA coverage can be different since there is no dependency with LTE.

  1. High path loss in 3 GHz so for DL coverage you should have almost same physical condition so that you can manage UL coverage of 4G in NSA.
  2. Same reason as above you have restricted UL/DL in SA, so that you should keep transmitter near to clutter as you are not going to get > 300m -400m coverage in 3GHz SA
  3. Horizontal and Vertical beams you can manage softly in 5G so clutter height will not disturbe you w.r.t 4G.

What about Tilt?
Is NR antenna having Tilt = LTE Tilt + 2?

It’s all about your link budget.
You can’t make tilt fix on assumption basis.
But it will not bother you lot like 4G.

Redirection to LTE use with SA using RRC release.
I think for NSA it’s not possible redirection to LTE it’s like SCG to release.

From 4G to 5G.

If you see the combined Antenna internal system of any AAU, they keep 5G part on top of 4G.

But still it can be subject matter of discussion with system integrator or planning design.

As NSA use smart antennas instead of passive which are capable of beam forming so while installing antenna for NR need to be more careful to mitigate in.terference between beams.

Yes it’s possible scenario.

Refer to this point: :point_down:

Thanks, I got your point.
It’s beam profiles we need to control as well with GoB calculation but in general tilt is more then LTE seen.

No one can answer your question about tilt if you don’t have basic link budget clutter level.

What you are suggesting tilt+2 is just an assumption that will change site by site and clutter.

I have seen both here in Spain, and the criteria is unclear, as every operator is different, and even an operator has a different criteria depending on the site.
They seem to agree in an antenna migration to be able to allocate new frequencies. Most of the 3G is being migrated to mixed mode 3g/4g.
What we see here mostly is NSA. IOT cells I have seen so far are B20, defined on some LTE basebands.

Example 1

Example 2

So the old antennas are being migrated to be able to allocate mixed frequencies on a baseband system, and they add active antennas probably aiming at 5G SA, even if it’s NSA actually.

1 Like

A matter of opinions really. You can keep height of 5G antennas similar to 4G antennas, but if you can’t and you need to stack them then I prefer to put 5G antenna above a 4G passive antenna, for following reasons:

  1. Our 3.5GHz spectrum allocation has much larger bandwidth than a remaining 4G, thus the biggest throughput contributor is at “prime location”.
  2. 3GHz band has worse link budget, thus again should be higher to risk less obstructions than lower bands.
  3. 3GHz band has worse diffraction, ie waves “propagate less” behind obstacles, diffraction angle matters, at least in theory.
  4. If you are using MaMIMO, then such antenna typically has much larger “scanning” range with your beams, thus it’s better to place it higher to avoid rooftop clipping…in a case you are not at the roof edge, but somewhere at a center.
  5. Latest MaMIMO antennas are smaller and lighter than multiband 4G antennas, thus if you need to put one antenna higher… it’s easier to choose 5G.