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kyokuman
2011-06-24, 11:35 PM
Hi,

Using Huawei, and No TMA installed, I have Negative values for Pathbalance. Showing DL losses are more important in DL !

How is it possible? I am sure not having any Hardware problem.
Why DL losses can be higher

How TRX power can affect pathbalance, as if im not mistaken, pathbalance is the difference of pathloss !


Thanks for your help!

rimoucha
2011-06-26, 03:06 AM
Hello,

Path balance is defined as follows:

Uplink/downlink balance = uplink path loss - downlink path loss = (actual TX power of the UE - uplink receive level) - (TRX power on top of the cabinet - downlink receive level)

Generally speaking,if the path balance is between -9dB & 9dB it's acceptable but if you have greater values then it's an issue to investigate.
High DL losses may indicate faults in the TX/RX channel, such as the TRX and the antenna.... But first you should verify that power level is OK (the parameters to check are Power level and Power Type)

Best regards,

kyokuman
2011-06-27, 03:03 AM
Thanks. What do you mean by Power Type?


But my question was rather that :

- Why -9dB is ok? what makes DL pathloss bigger by 9dB than UL?

- Why adjusting TRX power can affect pathbalance, as pathbalance is the difference of path loss. (Which is difference between received level and Transmit power). Example, if u transmit less, u gonna receive less, but pathloss is same....

Thanks for help!

Md.Moniruzzaman
2011-06-27, 11:44 AM
This is due to different frequency band in Uplink & Downlink.
Pathloss has a relationship with Transmit frequency
If Transmit frequency high Pathloss high.
So if use FDD then there will clear difference in Uplink & Downlink Pathloss

kyokuman
2011-06-27, 04:18 PM
Hi,

Thanks. Yes I agree with that.

But why recommending power adjustment (Huawei document) to help balancing equally the pathbalance?