64QAM Utilization

[electron]

Hi friends,


I got some problem for HS benchmark. The problem is 64QAM modulation usage in our cluster is very less considering(CQI is very good, RSCP and EcNo are very good as compare to my competitor) even close to site 64QAM will not assign. System is E*******. How we can utilize 64QAM ? there is very significant difference from my competitor and my network

How system is deciding which modulation code should be assign to a UE?
How we can give some offset to the mechanism for 64QAM assignment?


Thanks

[ninjafine]

Hi! CQI value of 26 is required for 64QAM. Check first in a static test that you get 64QAM Modulation Rate = 100% for CQI=30. What was the average CQI in your benchmark?
Here some results from real drive-test. Is this results (CQI, Codes, Throughput) comparative with yours?
26849

[elkador]

This is probably a silly suggestion, but :
- Did you enable 21mbps license in your network : this drives the use or not of 64QAM
- Did you use for the drive-test a UE that was 64QAM capable (please do inspect the firmware, it may be related)

And yes. you will require at least CQI = 26. Be sure to compare apple to apple : your competitor may use Dual Carrier...

[halilifatata]

so complex isn't it ?

[electron]

This is probably a silly suggestion, but :
- Did you enable 21mbps license in your network : this drives the use or not of 64QAM
- Did you use for the drive-test a UE that was 64QAM capable (please do inspect the firmware, it may be related)

And yes. you will require at least CQI = 26. Be sure to compare apple to apple : your competitor may use Dual Carrier...

Is there any parameter to utilize 64QAM more in network ?

[elkador]

Not to my knowledge. Only way to improve 64QAM usage is to improve your CQI, i.e. improve the radio condition to be clean (low interference from adjacent sites).
Tweaking specific parameter to artificially improve 64 QAM usage without dealing with the radio condition directly will lead to higher BER, so higher retransmission and then overall lower throughput than if you sticked to 16QAM.

[elkador]

One last thing : latest Qualcomm chipset are able to use ICI (interference cancellation), the effect is (in average) to improve by 3 to 5 the perceived CQI by the UE.
So the UE is able to use more often 64QAM. This is what I was referring when asking you to look at the firmware part on the UE used.

Hope this helps...

[electron]

One last thing : latest Qualcomm chipset are able to use ICI (interference cancellation), the effect is (in average) to improve by 3 to 5 the perceived CQI by the UE.
So the UE is able to use more often 64QAM. This is what I was referring when asking you to look at the firmware part on the UE used.

Hope this helps...

Thanks for your information. Actually the simple point is benchmark performed by the exactly same equipment, RSCP,CQI,EcNo even is better than Competitor but 64QAM modulation code utilization is meaningful lesser than competitor they are not using dual carrier also! this is strange . By the way i am looking for counter(RBS or Cell level) to give me modulation code distribution in RBS or Cell level. Do we have such a counter?

Thanks

[elkador]

You can have (at least with NSN equipement) distribution on CQI and Modulation type at the nodeB level. Probably not a counter, more a direct monitoring connection to the NodeB would be able to give you that.
However, if you have a better Ec RSCP, Ecno and CQI, you should have a better overall speed. Is it the case?

If not, I suspect you have some faulty parameter set in your network. (for example 64QAM enabled, but you still limit the scheduler speed at 14mbps. Or you use too many codes for signaling, which reduce the likelihood of ramping up to 64QAM.

Usually to reach 64QAM for a UE, you need :
- Use all free codes
- Lower at max the coding rate
- Then (and only then) start upgrading the modulation scheme.

[ninjafine]

Thanks for your information. Actually the simple point is benchmark performed by the exactly same equipment, RSCP,CQI,EcNo even is better than Competitor but 64QAM modulation code utilization is meaningful lesser than competitor they are not using dual carrier also! this is strange . By the way i am looking for counter(RBS or Cell level) to give me modulation code distribution in RBS or Cell level. Do we have such a counter?

Thanks

Hi! I would check also available power for HSDPA since 64QAM is very sensitive to it. What is the maximum power available in Radio Units? It might be that you have more feeders RBS without remote RU than your competitor.

[electron]

Hi! I would check also available power for HSDPA since 64QAM is very sensitive to it. What is the maximum power available in Radio Units? It might be that you have more feeders RBS without remote RU than your competitor.

Different sort of RBS in E/// (3X00,6000,38XX) also all RUs are 60W with 2 carrier

Which parameter can cause such a problem

For code allocation we already using dynamic code allocation

Any suggetion?

[ninjafine]

Different sort of RBS in E/// (3X00,6000,38XX) also all RUs are 60W with 2 carrier

Which parameter can cause such a problem

For code allocation we already using dynamic code allocation

Any suggetion?

I would first eliminate next two types of RBS that can cause problems (both can be found from statistics):
- RBS's that don't transmit with 20 Wt (depends on PCPICH power) per cell
- RBS's that have 64QAM Ue's but don't allocate any 64QAM TBS (meaning some problem with 64QAM activation, e.g. Enhanced Layer 2 is not activated)


Thanks and reps are apreciated.

[electron]

I would first eliminate next two types of RBS that can cause problems (both can be found from statistics):
- RBS's that don't transmit with 20 Wt (depends on PCPICH power) per cell
- RBS's that have 64QAM Ue's but don't allocate any 64QAM TBS (meaning some problem with 64QAM activation, e.g. Enhanced Layer 2 is not activated)


Thanks and reps are apreciated.


Thanks . By which ocunters we can see the 64QAM allocation destribution?

[ninjafine]

I'm using 64QAM % = 100*pmAck64Qam/(pmAckQpsk+pmAck16Qam+pmAck64Qam). Let me know your results.

[electron]

I'm using 64QAM % = 100*pmAck64Qam/(pmAckQpsk+pmAck16Qam+pmAck64Qam). Let me know your results.

Can you please let me know what exactly is showing?

As far as i understood it is showing ACK and NACK and the counters also are PDF counters.

Could you please share your BO report?


Thanks for your information friend