DSS 5G versus Carrier Aggregation in 4G

Hello,
One question about DSS 5G: is it true that there is no CA in 4G for the UE that has DSS configured so only the LTE anchor carrier is active in 4G?

Till now we have observed DSS implementation in low band 600 and 800 Mhz only and these bands dont have CA in 4G due to 5-15 Mhz single carrier availability for operators.
Not sure about the technical challenge in implementation though.

Strongly depends on which LTE bands are deployed.
There are DSS devices which do perform LTE CA, I can mention Motorola EDGE and some CPEs.

According to Ericsson, DSS can only be used wit a single LTE CC.
In Rel 17 it will have CA4G+DSS.

Isn’t it supposed to mean to have more than one DSS carrier sharing spectrum?
Example: F1_LTE + F2_DSS + F3_DSS?

By Ericsson’s explanation it looks like F1_DSS+F2+DSS+F3_DSS not possible now.
But you say it is possible F1_DSS+F2_LTE+F3_LTE now.
:laughing:

Lol, I’m 100% sure you can do: F1_LTE + F2_LTE + F3_DSS, a single DSS layer with multiple LTE CCs.
That was my understanding of the original question.
Not sure about multiple DSS layers, as the example F1_LTE + F2_DSS + F3_DSS.
Not sure about what the slide states, either the first or the second.

Thanks, that was my original question:
“I’m 100% sure you can do: F1_LTE + F2_LTE + F3_DSS, a single DSS layer with multiple LTE CCs”

Ericsson, I think, is about F1_DSS + F2_DSS + F3_DSS.

For this, I have tested total of 3CCs, b28 (anchor) + b1 + n3 (DSS layer), so 2 x LTE_CA + DSS.

Ok thanks, all clear now. :grinning:
I don’t have too much DSS experience.

No problem, Sir! :wink:

The key point for DSS, is to understand the MBSFN and non-MBSFN allocations, this is the real magic!

And from the non-MBSFN, you end up in the Rate Maching mentioned by Ericsson.

This whitepaper from MKT is pretty neat:

I don’t think there is any restriction on lte CA for DSS. The limitation is related to LTE band + NR band that are overlapping
For example if F1 is LTE, F2&F3 are DSS then in general with NR F3, UE can do F1 + F2(DSS) + NR F3(DSS) but cannot do F1 + F3(DSS) + NR F3(DSS)
B41/N41 is exception because 3GPP allows it