Hi Experts.
Apart from Verizon in US, do you know other MNOs that have deployed commercially 5G in mmWave on a large scale?
I mean tens of thousands of cells, not just few tens of cells in downtown…
Verizon deployed it in major cities in US → Cellular Tower and Signal Map
I think SK in South Korea, but it didn’t go as planned so they had to give up their mmWaves license.
I think there is also mmWaves deployment in Japan, but I don’t know MNO name.
To me, 5G in mmWave is a waste of time and money.
Does not penetrate in indoor, cell range is less than 300m.
Way too expensive for coverage provided.
More than 80% of traffic is coming from indoor.
I wonder how 6G is going to make in THz spectrum.
They may solve DL with Giga-MIMO but uplink…no way to solve uplink in THz spectrum.
Werizon deployed it a lot!
I think was not a good idea…
I think mmWaves has very specific use cases, for example very crowded locations (concerts, stadiums, …), or FWA deployments.
THz will also have very limited use cases, for example ISAC (Integrated Sensing and Communication) and capacity layer for very crowded locations.
This part of the spectrum is indeed not useful for Macro or Micro Outdoor to Indoor O2I coverage scenarios.
mmWaves can be useful in dense urban environments if the inter site distance ISD is very small (300 m for example).
But they have to couple it with a coverage layer also.
Also RIS (Reconfigurable Intelligent Surfaces) will play a key role in enhancing coverage in mmWaves and THz scenarios.
I am not so sure.
Will help in Downlink indeed, but who will take care of Uplink?
I’m not sure, but I think RIS can also work in UL, after all if you can establish a downlink between BS → RIS → UE, why not use the reverse link for Uplink?
But in DL you can have directional antenna, in UL you cannot, there is no massive MIMO in UE.
I mean for Uplink, not for Downlink.
Yes, but assuming UE is not moving, RIS can also mirror the waves from UE to BS.
Are you aware of UEs that have other than omni pattern in uplink for transmission?
Even in 5G there is UL-MIMO with max 2 layers.
That means 2 antenna in the UE and each antenna pattern in UE is omni, I think.
For transmission I mean.
I’m not very sure, but I think FR2 antennas at the UE are directional.
I am just thinking how this would be possible.
You keep the UE on the table, you never know in which direction is the gNodeB.
Omni antenna will accommodate this scenario, directional antenna will fail to accommodate this.
Maybe someone can confirm if UE transmission antenna is directional or not.
To my understanding it is omni.
Antenna gain can be very different between UE and gNB, for example directional antennas at the gNB can have a gain of 20 dBi, (less or more depending on the array configuration).
However UE antenna gain can be 3 dBi for example (less or more depending on the configuration).
You can perform beam sweeping in the Uplink to catch a Downlink beam I will show a photo to illustrate how:
I think that is for reception, I am aware that this is possible.
The whole process is called beam management.
Assuming your UE wants to access the network it has to catch SSB beam, and since UE antennas are directional UE will perform beam sweeping to find the best SSB.
But again that is for Downlink.
I am speaking about Uplink.
Beam sweeping of the UE can be done for Downlink. I agree with this.
Yeah, I know. I’m also talking about Uplink, after gNB and UE establish a beam pair (suitable Uplink beam with suitable Downlink beam) they can communicate.
In both directions (Downlink and Uplink).
To have beam sweeping in Uplink you need to shift the phase of several TX antenna in the UE.
And currently are just 2 of them.
Even if you put 4 or 8 they still need to be omni. If directional, then gnodeB may be out of the main lobe of the UE directional antenna tranmission.
I don’t think there are only 2 antennas at the UE, can you confirm this?
Because in 5G Release 16, MU-MIMO can work with 4 layers with each UE.
And this needs 4 antenna ports at the UE side.
Samsung Galaxy S22 can support 4 MIMO streams in the Uplink:
4x4 is a very common configuration in LTE and 5G, and I think a lot of UEs support this configuration.
