Can b20 be Pcell in CA_7-20?

Specs & Protocol Testing
1

Hi Experts.
I have 1 query.
For 2CC CA in 3gpp it’s mentioned CA_7-20 so it’s like band 7 as pcell and b20 as scell.
Can we use b20 as pcell as well?

image

2

To verify answer check any tdd - fdd combination.
Because TDD pcell and FDD scell won’t work at all.

3

Sensible question.
I would say no…but just a surmise.
Would want to find out what the specs say or some expert here…

4

Here b20 and b7 both are FDD only.

In 3gpp 36.101 it’s mentioned CA_7-20.
I didn’t see like CA_20-7 in specs.
But it’s very different still it’s seen in performance that b20 having scell attempt for b7.

Really confusing… :frowning:

5

CA 7_20 in 3GPP means any of these band can be pcell or scell.
But while sending UE capability UE include its support separately.
For example if UE only support 20 as PCell (20 will have dl /ul both and 7 will have dl only) then UE will not send 7 dl/ul and 20 dl.

Hope this will help you.

6

Ok but if you look b20 combination table 5.5A-2 in 36.101 you will not find any combination of b20 with b7 I mean like CA_B20-B7.

image

7

Because it’s already covered in B7-B20.

8

This I find for interband 2 CA:

image

9

B7-B20 means anyone can be pcell any one can be scell.

10

Please tell where it mentioned any specs reference.

11

No where it is mentioned.
It’s well understood.
You will not find any opposite combination in 3GPP.
It doesn’t mean it is not supported.
If A-B is given in 3gpp, ou will never find B-A.

12

Thanks @sadanandk2 .
I’m going item wise classification, let me check further.

For any band combo in my view item0 indicates pcell only.
Then item 1,2••• like scell 1,2.

13

Yes, correct.

14

CA_7-40 means B40 can’t be pcell I guess.
No UE can support TDD Pcell and FDD scell.

15

No, many UE there already supporting TDD pcell and FDD scell.

16

We have enabled TDD - TDD CA however.

Any example?

17

Samsung S7

supportedBandCombination-r10 value 8
    supportedBandCombination-r10 value 8 value 1
      bandEUTRA-r10     : 7
      bandParametersDL-r10
        bandParametersDL-r10 value 1
          ca-BandwidthClassDL-r10     : a
          supportedMIMO-CapabilityDL-r10     : twoLayers
    supportedBandCombination-r10 value 8 value 2
      bandEUTRA-r10     : 7
      bandParametersDL-r10
        bandParametersDL-r10 value 1
          ca-BandwidthClassDL-r10     : a
          supportedMIMO-CapabilityDL-r10     : twoLayers
    supportedBandCombination-r10 value 8 value 3
      bandEUTRA-r10     : 20
      bandParametersUL-r10
        bandParametersUL-r10 value 1
          ca-BandwidthClassUL-r10     : a
      bandParametersDL-r10
        bandParametersDL-r10 value 1
          ca-BandwidthClassDL-r10     : a
          supportedMIMO-CapabilityDL-r10     : twoLayers
18

Not possible, I guess.

19

Does it indicate b20 as pcell and b7 as scell?
Is understanding correct?

Oppo, Vivo, Samsung… it’s very common combination.
Please tell which device not supporting it.

20

I have written confirmation from all suppliers no UE support TDD as pcell + FDD as scell.
4G.