What is PIM?

PIM (Passive InterModulation) occurs when signals from multiple high-power transmitters interact, typically with objects in the environment, creating nonlinear effects that interfere with the uplink signal and severely degrades throughput.

It’s not a new problem for the mobile network, but one that is difficult to identify and solve. Many mobile operators don’t know there is a PIM problem until after installation and site monitoring reports flag a performance issue.

Frequency (MHz)

Common Sources of PIM

Old cables, connectors and antennas

Diplexing new carriers onto existing cable runs

Cluttered cell towers and rooftops with many reflections

Frequency band combinations vulnerable to PIM

The Cost of PIM

With some simple math we can estimate the cost of PIM via its negative impact on traffic:

Unfortunately, when PIM occurs it usually affects more than just one site. Also this simple math does not incorporate subscriber churn due to slower speeds and reduced throughput. When these are taken into account, the financial impact of PIM is even larger.

Case Study

Vulnerable band combinations

The Problem

Close proximity of another operator's band created Triple beat and IM3 PIM. Accessibility and retainability suffered as a result.

The Solution

Significant KPI improvements were achieved after the c-ONE PIM Canceler was deployed.

The Outcome

+41% Recovery in uplink accessibility & retainability

+22% Downlink throughput

+45% Uplink throughput

+53% Uplink traffic volume

-13% Drop rate

9dB RSSI improvement

6-9dB PIM cancelled

c-ONE PIM Canceler

Benefits of ISCO's Solution

Eliminates potentially lengthy and costly troubleshooting on site to identify the source of PIM and resolve the issue. Often the fix is …

Higher Tx power: By removing PIM the downlink power can be increased, which leads to greater range and higher traffic capacity.

Versatile and Adaptive: This is a dynamic solution operating in real-time that adapts to the changing environment, and can cancel intermittent PIM interference (weather? Reflections from cars????)

Portable version enables…

How it Works

The c-ONE PIM Canceler from ISCO is deployed on the CPRI uplink between the BBU and the radio, and is often co-located with the BBU.
Advanced, patented algorithms operate on the raw I/Q data to detect, analyze, and remove PIM in real-time, regardless of its source.

PIM levels before and after ISCO cancellation

PIM Cancellation Resources


Restore Service Immediately While You Permanently Resolve PIM


C-ONE PIM Canceller Data Sheet


PIM Best Practices


Network Optimization for 5G

Want to learn more about
PIM cancellation?