Hello Experts.
Does any vendor equipment logs provide info on external interference?
What are the ways of working to find the source of external interference, except spectrum analyzer?
Admin note: this post was updated with image below.
Huawei – Online and Offline FFT Scan.
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There are performance counters per each PRB.
Like in Huawei you have Channel Quality Measurements
Counters:
- L.UL.Interference.LinearAvg (Linear average value of PRB-level interference noise detected in the uplink.
- L.UL.Interference.Max.PRBx (Maximum interference and noise received by PRB x in a cell)
- (where x is PRB 0,1,2 etc)
With max and average interference.
And if for PRB x the max and average interference is the same, very high like -90 dBm, then there is external interference!
Of course this depends also on P0_Nominal_PUSCH settings.
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I sometimes use NEMO Outdoor to locate external interference, like repeaters, other operators’ faulty RRUs, etc. Before it I check KPI (high RTWP, Average NI of carrier, etc), and approximately map the location. Also I search for repeaters visually 
Good luck!
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Hello friends/experts, I wanted to ask what steps you take for external interference mitigation in your networks.
- Check for fault units (RRU, RFU, …).
- Check for loose connections (Jumpers).
- Check for the starting time of the interfering signal and study what change happened in this particular area (new band installed, new solution, …)
- Check if there are some critical governmental areas (prisons) - we had a problem a long time ago where a prison installed a cellular jammer.
- Inform the CRA (Communication Regulatory Authority) for they contact the spectrum and will be aware by making spectrum scanning about the illegal signal source.
In addition, there are some features available to suppress interfering signals, but it’s best to check with the vendor’s BSS team. You can also try adjusting tilts or re-azimuthing to see if the issue resolves, especially if the interference is directional or specific to a particular cell or sector.
Thank you. I’ve already conducted source hunting, as the interference is external. In our region, many users use repeaters to improve coverage in basements or congested areas, which is a major source of interference. To address this, we perform spectrum scanning and source hunting.
Recently, we’ve tested downtilting the cell slightly, which sometimes helps reduce interference by limiting coverage. However, this can lead to neighboring cells experiencing interference as their footprint expands and begins to pick up the source. Features can improve OSS KPIs, but the interference itself often remains.
Are there any additional steps you use in your part of the world?
What level of impact did you observe on the spectrum analyzer?
Is it limited to just a few RBs that you could blank without affecting the PDSCH and PUSCH?