CA_SCELL_ACTIVE_UE_MAX is limited to 50

[fahmi]

Dear Nokia experts,

Counters shows that the the maximum number of DL CA UEs in the current cell which have one activated SCell is limited to 50.
Trying to improve CA usage, I adjusted the pram maxNumCaConfUe from 50 to 100 and I got an increase of the maximum number of DL CA UEs in the current cell which have one configured SCell. But the Activated SCell remains limited to 50 !!
Our setting to Activate the secondary cell for the UE is Blind activation which means that secondary cell is activated right after configuring it.

Any explanation to this behavior?

42016

[Soltech]

Hi Fahmi,

Carrier aggregated UEs with 1 or more SCell need more resources than nonCA Ues (PUCCH and MAC PS);
Therefore limiting the amount of CA-UEs is necessary. So check PUCCH (uplink) related feature and there limitation.

maxNumActUE >= maxNumCaConfUe
max(maxNumCaConfUeDc, maxNumCaConfUe3c) <= maxNumCaConfUe

Check below feature and capacity as well.
• LTE1799 RL70 FSMr3 Capacity and Dimensioning (Standard)
• LTE1963 FDD-LTE 15A FSMr3 Capacity and Dimensioning (Standard)
• LTE1130 Dynamic PUCCH allocation (Standard)
• LTE2664 Load Based PUCCH Region (Standard)




Br//





Dear Nokia experts,

Counters shows that the the maximum number of DL CA UEs in the current cell which have one activated SCell is limited to 50.
Trying to improve CA usage, I adjusted the pram maxNumCaConfUe from 50 to 100 and I got an increase of the maximum number of DL CA UEs in the current cell which have one configured SCell. But the Activated SCell remains limited to 50 !!
Our setting to Activate the secondary cell for the UE is Blind activation which means that secondary cell is activated right after configuring it.

Any explanation to this behavior?

42016

[fahmi]

Thank you Soltech,

With Dynamic PUCCH allocation activated, still don’t see what could be behind the restriction of the Maximum number of UEs with one activated SCell to 50 !

[DJ Download]

What is your sCellActivationCyclePeriod setting?
If it is 2 seconds, then try change it to the lower setting (e.g. 0.001s)


/DJ D

[fahmi]

Dear,

This parameter (sCellActivationCyclePeriod) is not used when "sCellActivationMethod" is set to "blind". And for my case I am using Blind activation which means that secondary cell should be activated right after configuring it.

[khurrambilal01]

What is MultScellreleasetimer value for De-configuration?

[fahmi]

Dear,

It's set to "0" and I don't think setting this timer may cause the limitation of Maximum number of UEs with one activated SCELL

[DJ Download]

Hi,

This is from the parameter sheet:

sCellActivationMethod

This parameter defines the method to be used for SCell activation.
The meaning of the values is as follows:
'blind' means that SCell is blindly activated and it is never re-activated after the expiration of the timer sCellDeactivationTimerEnb.
'nonGBRBufferBased' means that SCell activation is triggered depending on the non-GBR data in the buffer. For a UE with two configured SCells, SCell activation is triggered depending on the non-GBR data in the buffer in a joint way, i.e., one MAC CE command activates all SCells.
'nonGBRBufferBasedStepWise' means that for a UE with two configured SCells, SCell activation by one or more separate MAC CE command(s) is triggered depending on the non-GBR data in buffer in a step-wise way. In the first step one SCell is activated depending on the non-GBR data in buffer and after that depending on the non-GBR data in buffer the second SCell is activated if needed.

Note: The period of the SCell activation cycle is configured in sCellActivationCyclePeriod.



My understanding here, even with blind config option the activation / deactivation still uses sCellActivationCyclePeriod and sCellDeactivationTimerEnb

[djordjebeg]

HI DJ,

from description of parameter "sCellActivationCyclePeriod" : This parameter defines the period of the SCell Activation cycle. The parameter value is in seconds. This parameter is not used when "sCellActivationMethod" is set to "blind". Optional feature(s): LTE1089 Downlink carrier aggregation - 2 CC
when Blind activation is sued parameter is not regarded.

I propose to set :



LNBTS
sCellActivationMethod
0 (nonGBRBufferBased)
0 (nonGBRBufferBased)


LNBTS
sCellActivationCyclePeriod
2 (2s)/0 (0.5s)
7 (0.001s)


LNBTS
scellActivationLevel
1040 (0.75 TTI)
1010 (0.1TTI)






and on TOP if FL18A se release is in place :



LNCEL
scellFastSchedulingSelect 0-->1









enodeB cannot activate Scell without received periodical CQI from UE. The latest change will push UE to send CSI ( CQI) immediately after RB activation and therefore enodeB can immediately instruct UE to activate Scell via PDCCH MAC Command.

Br,

[fahmi]

Dear djordjebeg,

Please to confirm for your network if CA_SCELL_ACTIVE_UE_MAX is limited to 50 the same as my case

Thanks

[djordjebeg]

Hi fahmi,

it has value of 100 actually.

Br,

[ls2398]

What's your value of maxNumCaConfUeDc, that's also 50 by default and you have to change it as well as maxNumCaConfUe.

Also can I ask why you use Blind CA? It can be quite messy in an urban environment.

[taki]

Hi Fahmi;

we have same issue in our NW , did you solve this limitation ?

BR

[kevin_h811]

Hi Djordjebeg,

Please share the result if any...Thnks




HI DJ,

from description of parameter "sCellActivationCyclePeriod" : This parameter defines the period of the SCell Activation cycle. The parameter value is in seconds. This parameter is not used when "sCellActivationMethod" is set to "blind". Optional feature(s): LTE1089 Downlink carrier aggregation - 2 CC
when Blind activation is sued parameter is not regarded.

I propose to set :



LNBTS
sCellActivationMethod
0 (nonGBRBufferBased)
0 (nonGBRBufferBased)


LNBTS
sCellActivationCyclePeriod
2 (2s)/0 (0.5s)
7 (0.001s)


LNBTS
scellActivationLevel
1040 (0.75 TTI)
1010 (0.1TTI)






and on TOP if FL18A se release is in place :



LNCEL
scellFastSchedulingSelect 0-->1









enodeB cannot activate Scell without received periodical CQI from UE. The latest change will push UE to send CSI ( CQI) immediately after RB activation and therefore enodeB can immediately instruct UE to activate Scell via PDCCH MAC Command.

Br,

[plannerguy]

Hi

what is the value set for below paramtere - maxNumCaConfUeDc (Threshold to limit the maximum number of carrier aggregation configured UEs in a PCell (P-LNCEL); Dc (Double carrier) indicates that these UEs have 1 PCell (P-LNCEL) and only 1 SCell (S-LNCEL))

Rgds
Plannerguy