About the UL interference at IBS

[Interface]

Hi experts,
We have a problem at our Net : The UL interference of some IBS very high while the traffic is very small. What causes do make this and how do we find them ?
Thanks you!

[romagdinio]

hi,
it may be due to one of the below problems:

1- hardware problem.
2- external interference problem , and you can detect this bu connecting a frequency analyzer to the antenna and checking if there is an external interference in your network UL band.

BR,

[Interface]

Thanks for your answer.
But all things you said are fixed. This problem usually happens in Inbuilding Cell without the hardware problems or external UL interference.

[kryptonic]

Please check all feeder calculations and if they are done right taking into account all components etc and entered in the network correctly. Incorrect calculations is a major cause of experiencing UL RSSI. Not considering TMA in the path etc.

[Interface]

Sorry. I don't understand clearly your idea. Please explain more detail about your mean. Thanks.

[Philippe]

what is the level of RSSI measured?

[Interface]

This value of some sites are ~ 90dBm.

[Philippe]

Any intermodulation product (PIM) due to combination of verious systems in your IBS? Is it a multimode IBS (offering GSM and UMTS in different bands on same IBS)?