Does GSCN reflect offsettopointa and KSSB?

Hello Experts.

Does GSCN reflect offsettopointa and KSSB?

Also: how SSB position will be known from offsets in SA?

Admin note: this post was updated with image below.

GSCN is Global Synchronization Channel number and, in my opinion, does not reflect offset to point A and KSSB.

KSSB is in MIB 5G.

offsettopointA is given in RRC reconfig to setup 5G in NSA.

Check my post about it, might be helpful:

Thanks @Mohamedeladawi, I’ve seen it.

But what’s the relation between GSCN and offsettopointA?

Offset to point A represents RB 0, RE0 location.

Bottom of the used spectrum for an operator.

While GSCN is location of SSB where UE needs to search for signal for SSB sync.

If I undertand question correctly: OffsettopointA specify the RB offset between CRB0 and CRB overlaps with the start if SSB; and Gscn in general used to degine SSb center freq and offsettopointa and kssb is delivered to UE to identify the SSb position from the channel bandwidth as the UE detect ssb blindly and is mot aware about the exact freq location.

Offset to point A: Sent to the user to locate the exact position of SSB after the UE detected the SSB based on GSCN (center SSB freq).

But this GSCN matters just in SA.

In NSA is given to UE in the RRC reconfig to setup the SCG:

Correct.

This is for 5G NSA.

Part on the left for GSCN:

KSSB is in MIB 5G.

offset to pointA is in SIB1 SA.

Yes, correct.

I’ve seen logs in SA it has offsettopointA.

So GSCN for NSA only, right?

You will find it only in SA and this will be delivered in 5G SIB1.

GSCN can be used for both brother but it is mainly designed for 5G SA.

Synchronization raster concept.

GSCN is not only for 5G SA.

Yes for both.

:point_down:

So if UE know SSB based on GSCN why to use offesttopointA?

UE doesn’t know the location of SSB in the channel bandwidth.

It needs to know the exact location in the channel bandwidth.

So this will be known through offsettopointA.

This GSCN should do it right?

As it’s giving the centre of SSB.

Center of SSB.

But still he dont where the SSB located in the channel bandwidth.

Channel bandwidth for example.

N78 100 Mhz.

GSCN if the center freq of ssb which is 20 MHz.

If UE knows the centre it can detect it easily.

No.

There is a big difference between SSB and channel bandwidth.