More than one SSB at two different frequency locations?

5G NR
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1

Hi Experts,

Can there be more than one SSB at two different frequency locations?

The parameter SSBSubcarrierOffset (k_SSB) says that if the value is > 23 for FR1 or > 11 for FR2 then the current MIB won’t have information of coreset #0.
So there won’t be SIB1 associated with this SSB and the parameter pdcch-ConfigSIB1 will provide the frequency location of the SSB which has an associated SIB1.

That means UE will look at different frequency locations for another SSB and SIB1?

2

It is not possible to have two SSB at different frequency location.
There is no mention of that in specs.
The parameter mentioned is used in NSA; since UE don’t need CORESET#0 in NSA, all SSB location and information is sent in RRC message.
Kssb > 23 means SIB is not present.

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3

Hi @Sakshama_Ghoslya

As per my understanding, there can be multiple SSBs located at different positions. So yes, there would be another SSB.

4

Hi @Nitin those multiple SSBs are at different time locations, like beam-0 and beam-1 in slot 0. They are different SSB beams, they have altogether different purpose of transmission.

5

In the same bandwidth there can be only one SSB, only at one frequency location, for different Bandwidth part you can have other SSB… There can be one SSB per Bandwidth part

6

Hi @Rodrigo_Gonzalez BWP is a UE specific parameter. Broadcast information has nothing to do with it. Different BWPs can overlap. One BWP can be completely inside the other one.
And MIB is the first information UE reads from BS. While reading MIB UE doesn’t understand BWP.

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Hi @samohiuddin, Thanks a lot.
What does it mean when they say, if k_ssb > 0, instead of Coreset #0, MIB contains frequency location of the SSB which has a corresponding SIB1?

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For same Carrier Bandwidth?

10

@Sakshama_Ghoslya

I did not get your reply. Are you saying since they are different beams, SSBs cannot exist at two places in a cell?

For me if there are two UEs, one NSA and one SA, network might deploy one SSB specifically for NSA without an associated SIB1 while the other SSB with SIb1 for SA device. Does this make sense to you?

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11

Hi @Nitin, Yes this makes sense. Thanks a lot.

12

Operator can have any many SSBs transmitted in a cell at different frequency locations. In SA Mode, One of these SSBs will provide the coreset0 and searchspace0 to get SIB1. In NSA Mode, SIB1 may not be present.

13

A BWP may or may not contain a SSB, if multiple BWP are configured/available. But surely one BWP will contain the SSB.

14

A cell can have multiple SSBs transmitted at different freq locations

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15

What is the advantage/benefit does Network/UE has with overlapped BWPs?

16

I have discussed that here:

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