Does kssb play any role in case of an ENDC?

Hi Experts,
Does kssb play any role in case of an ENDC?
Since SSB and PointA freq are already known.

Admin note: this post was updated with image below.

This picture shows requirement of Kssb:

See here for more detail:

This makes sense for SA.
But what’s the use for NSA when SSB and pointA freq are explicitly given?

I think it is just a provision to keep some offset in terms of subcarrier between first subcarrier of SSB and last of non SSB CRB.

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But how does this help in ENDC where we already know this difference and provide it to UE?
UE doesn’t need to know this.

We have 3 terms: POINT A ,OFFSET TO POINT A ,SUBCARRIER OFFSET(Kssb)…in nsa case offset to point A correspond to NR ARFCN.
Hi anyone worked over CSG cells having idea of proximity indication please let me know.
Need to discuss in which conditions UE will report proximity report.

As per 3gpp, For SA
FR1 kssb value 1 to 23
FR2 kssb value 1 to 12

For NSA, we should keep kssb value for FR1 more then 23 (we can give value upto 31) and for FR2 more then 12 (we can give value upto 15).

Base on this UE will ingoner Kssb value for NSA only.

Like for NSA- FR2 case if we keep Kssb value as a 15, then UE ll ingoner Kssb value.
For the same NSA case if you keep Kssb value less then 12 then UE will consider that value and base on that UE search for SSB. Then UE could not find SSB location.


But even a value of 11 for FR1 shud not make any difference for UE.
As it already knows SSB location, no?
In NSA case.

The Kssb shall play an important role in case of an ENDC. This come to the basic function of kssb, which inform UE the the carrier frequency separation of two concurrent active carriers, which help UE be aware that its RF front end design to avoid the adjacent channel interference. According to info @Ashish_Satasiya, Kssb should chose a larger value in NSA mode than in SA mode, this is because in SA mode ENDC, two active modem in UE are better synchronized than NSA mode, which put less constrains on kssb.

the channel can be using scs of 60kz and ssb can be using 15 or 30khz in that case the subcarrier0 of ssb wont exactly match with subcarrier0 of the first RB hence we need Kssb to define exact location of ssb

Can anyone explain or point to any good material explaining point A and kSSB concepts in 5G?

It is well explained in 5G in Bullets book. Thy there.

I had referred this topic in same book.

I think it is explained in pg. 123/124.

But still not clear with it.

Hi, you can check here too:

Thanks for sharing the link. This has certainly enhanced the understanding although I would say I am still not there yet.