Is searchspace ID 0 used for paging monitoring or is it only used for searchspace ID 1?

Specs & Protocol Testing
1

Hi All.

For paging: is searchspace ID 0 used for paging monitoring or is it only used for searchspace ID 1?

2

Common type 0: used for SIB1 (SI-RNTI)
Common type 0A: used for other SIBs (SI-RNTI).
Common type 1: used for Random access - RACH (RA-RNTI, TC-RNTI)
Common type 2: used for Paging (P-RNTI)
Common type 3: used for Gropu signaling (power control, SFI, etc)
UE-specific: UE specific signaling

3

So, can’t paging be configured for search space id 0?

4

Search Space Id 0 is only for SIB1.

5

Is it for 5G SA?

You mean can’t be for paging?

6

Yes, correct.

7

But it’s configurable.

So let’s assume used paging in searchspace 0. Then…
It will not work? Why?

It is for 5G, right?

9

Yes. Only for SA. For NSA no need for Tx of common info.

10

Ssid anything possible within the range.

11

Got you, thanks.

Any idea why searchspace 0 cant be used for paging monitoring?

12

Remember that for the selection procedure, the UE must get the MIB, then it will decode the PDCCH using the SI-RNTI with the Type 0 Common Search Space (CSS).

This will provide the SIB1 which is your INDEX for the remaining SIBs.

From SIB1 the UE will extract the pagingSearchSpace and then with the Type 2 CSS the PDCCH decoded using the P-RNTI which allows recepttion of PDSCH resource allocations for Paging Messages.

13

Yes I understand that.

So why searchspace 0 cant be used for paging?

I know it’s for sib1. So can be also for paging? Or why not?

14

I think UE will be confused, at least for Nokia is like that. :wink:

Don’t know for other vendors.

Must verify on 3GPP specs.

15

One CORESET can be associated with multiple Search Spaces, but every Search Space is unique.

As per 3gpp, search space 0 can be only used for SIB1, but CORESET0 can be used for other CSP also.

16

Thanks for your info.
Could you please show where it’s mentioned in spec / 3gpp thats searchspace 0 unique for sib1?
I can find those info in the 3gpp… :frowning:

17

Search Space Type Summary
Search Space Type Summary1124×302 92.7 KB

18

As I understand, the pagingSearchSpace IE can have all values {0,…, 39} (see 38.331 in PDCCH-ConfigCommon IE).

But her you’re saying that searchspace id 0 can’t be used for paging and its only for sib1?

19

Are you sure these values are css types?

20

Yes, it’s located in 38.331.

21

Sorry, your understanding is not correct.

Check again about the IE’s exact values and its interpretation correctly.

For any further doubts share the print/snap of the text you’re reading for better understanding.