SIB11 and cell reselection in idle mode ?

[fahmi]

Hi all,

Have you any idea, when the UE is in idle mode, how many 3G cells could it scan from the SIB11 ?
Could it scan the hole cells declared as an interfreq neighboors or only 2 cells ?

Vendor: Huawei.

BR,
Fahmi.

[ritgail]

Hi all,

Have you any idea, when the UE is in idle mode, how many 3G cells could it scan from the SIB11 ?
Could it scan the hole cells declared as an interfreq neighboors or only 2 cells ?

Vendor: Huawei.

BR,
Fahmi.


Generally, SIB11 neighbors(intrafrequncy/intra/IRAT) are meant to be measured by UE on every DRX cycle. It will start searching for intrafrequncy neighbors if Ec/Io has gone below a certain threshold( Ec/io -8db for example) of the current cell. similarly it will scan IRAT neighbor if Ec/io or RSCP has gone below -14db or say -95dBm( say 4db threshold with Qqual min -18db).
In System Information Type 3, these values are present. SIB11 gives neighbor w.r.t current cell with Offset values.

UE scan properties are not vendor specific as far as i know.

Push the repo;)

[ninjafine]

In 3GPP specifications, there are some inconsistent requirements. On one hand the SIB type 11 message can contain 31 intra-frequency neighbors, 32 inter-frequency and 32 GSM, but the length of SIB11 cannot exceed 3552 bits. You may use some recommended values from attachement. Otherwise Ue may skip some important neighbors in measurements.
26590
Thanks and reps are appreciated.

[plannerguy]

Hi

47 neigbors are created in SIB11, and measuremnts in NSN system is accorsing to the ID defined for adjcencies..



Regards
Plannerguy

[fahmi]

Hi all,

So maybe I have to correct my ask.

I heard about some SIB11 limitation when scanning more than 2 different 3G frequencies in idle mode.
For example, in a network where we have 4 different carriers (F1,F2,F3 and F4).
In idle mode the UE select F1 in first time and we have Interfreq declarations with all the other freq (F2,F3 and F4).
With this limitation, the UE could only reselect F2 or F3 and not F4 because, as I know, SIB11 does not support more than 2 different frequency to scan.

So, here the limitation, I am asking about, is a frequency limitation and not the number of cell declared as neighbors in idle mode.

Hope the question is clear.

Waiting for your comments.

BR,
Fahmi.

[ninjafine]

This is from 3GPP. "For idle mode cell re-selection purposes, the UE shall be capable of monitoring:
- 32 inter-frequency cells, including
- FDD cells on maximum 2 additional carriers, and
- Depending on UE capability, TDD cells distributed on up to 3 TDD carriers, and
- Depending on UE capability, 32 GSM cells distributed on up to 32 GSM carriers."
So, if more than 2 inter-frequencies are in SIB11, some UEs may ignore excessive frequencies.
Thanks and reps are appreciated.

[jan74]

Hi

47 neigbors are created in SIB11, and measuremnts in NSN system is accorsing to the ID defined for adjcencies..



Regards
Plannerguy

Correct, the limit is due to the actual byte size of the message and allows only 47 neighbours in total. But enabling SIB11bis will allow you to increase that number.

[nupong]

We have a case here that we are trying to activate SIB11BIS(Huawei RAN13.0) but most of KPI become worse. Then Huawei HQ recommended us to deactivate SIB11BIS as known bug in RAN13.0

My question is in case SIB11BIS is deactivated and we do have more than 50 Nbrs, How could nbrs are selected to be broadcast in SIB11 only 47?

[scorpion]

32 GSM + 32 3G as per NSN...I beleive E///+Huwei also same.