maxdlpowercapability and dlattenuation

[fhusain]

Hi all,

I have searched alot but haven't been able to find a logical explanation in e******* docs regarding downlink attenuation. I need to understand the following:

1)Why do we have to add dlattenuation and ulattenuation for feeder loss?
2) What's the consequence of setting both DL and UL attenuation to Zero?

It's really absurd that we have dlattenuation values of up to 3-4 db, based on feeder characteristics and this has direct impact on maxdlpowercapability. In our case, 40 watt per carrier is reduced to 20 watts or less ( 46dbm-3.4 db)

A 2 carrier huawei site having 40 watt per carrier didn't have dl power congestion, provided all physical attributes were same. When swapped to e*******, 80 watt rus, the cells are congested.

Thanks and regards

[Weiland86]

As far as I know this is for avoid dl/ul imbalance, and the values for dl and ul attenuation are related to the p0 value.


Hi all,

I have searched alot but haven't been able to find a logical explanation in e******* docs regarding downlink attenuation. I need to understand the following:

1)Why do we have to add dlattenuation and ulattenuation for feeder loss?
2) What's the consequence of setting both DL and UL attenuation to Zero?

It's really absurd that we have dlattenuation values of up to 3-4 db, based on feeder characteristics and this has direct impact on maxdlpowercapability. In our case, 40 watt per carrier is reduced to 20 watts or less ( 46dbm-3.4 db)

A 2 carrier huawei site having 40 watt per carrier didn't have dl power congestion, provided all physical attributes were same. When swapped to e*******, 80 watt rus, the cells are congested.

Thanks and regards

[electron]

Hi fhusain,

Welcome to forum.

Below are answer of your questions:

Q1-> A: attenuation value are important to understand how much is total available power in front of antenna after deducting feeder/jumper/ASC losses. RBS will use these values to automatically calculate read only parameter maxDlPowerCapability . Later on from RNC side power admission trigger will work based on this parameter as well as maximumTransmissionPower which has relation of "maximumTransmissionPower= maxDlPowerCapability -2" and accordingly CPICH power will be calculated as 10% of total available power. So i guess now you got the idea why and how attenuation value will influence performance or used.

Q2-> A :Refer to answer 1 !!

Q3-> A: First of all you have to check availability of RBS level license for 80W RU by INVH command? If it is available then check value of parameter maximumTransmissionPower for all sector/carrier. If it is -1 it means your RBS configured to propagate maximum 30W despite you installed 80W RU in RBS. So in total RBS power is very less that's why it is causing power congestion. Based on your question i understood that there was RBS swap from Huawei to E*******. Of course in advance you shall be sure about tilt and other configurations.
Hi all,

I have searched alot but haven't been able to find a logical explanation in E******* docs regarding down link attenuation. I need to understand the following:


Cheers

1)Why do we have to add dlattenuation and ulattenuation for feeder loss?
2) What's the consequence of setting both DL and UL attenuation to Zero?

It's really absurd that we have dlattenuation values of up to 3-4 db, based on feeder characteristics and this has direct impact on maxdlpowercapability. In our case, 40 watt per carrier is reduced to 20 watts or less ( 46dbm-3.4 db)

A 2 carrier huawei site having 40 watt per carrier didn't have dl power congestion, provided all physical attributes were same. When swapped to e*******, 80 watt rus, the cells are congested.

Thanks and regards

[fhusain]

Dear Electron,

Thanks for replying.

We have the license enabled for 40, 60 and 80 watts.
The problem is, 80 watts are going to be distributed between 2 carriers. This gives us 40 watt per carrier or 46 dbm. Based on this, if we are to subtract downlink attenuation from this power, we are left with mere 42 dbm or 16 watts. I'm comparing all this with Huawei system, which did not consider any downlink or uplink attenuation, and the effective maxtransmissionpower used to be 46dbm per cell. This neither affected the power control nor did it affect the pcpich.

If I set the dl/ulattenuation to 0, will it affect the power conrol mechanism?

[electron]

OK let me ask my question from another angle. Suppose you set Attenuation to Zero. Tell me what will be actual available power ? In this case how you gonna set CPICH according to total output power? One more thing in general is that Feeder by itself having loss per meter how Huaweii bypassing it without considering attenuation?


Cheers
Dear Electron,

Thanks for replying.

We have the license enabled for 40, 60 and 80 watts.
The problem is, 80 watts are going to be distributed between 2 carriers. This gives us 40 watt per carrier or 46 dbm. Based on this, if we are to subtract downlink attenuation from this power, we are left with mere 42 dbm or 16 watts. I'm comparing all this with Huawei system, which did not consider any downlink or uplink attenuation, and the effective maxtransmissionpower used to be 46dbm per cell. This neither affected the power control nor did it affect the pcpich.

If I set the dl/ulattenuation to 0, will it affect the power conrol mechanism?

[rumy]

The best way to find an real answer to your questions will be to trial Att=0. If you noticed Pwr congestion after swaping Huawei to E/// , keeping the same 46dBm/ cell/ carrier, you can compare Old Pdelay with new Pdelay...you may have changes in the traffic distribution. Do you know if Attenuation is affecting RNC AC?