Internal passive intermodulation (PIM)
There are two types of passive intermodulation (PIM): internal and external. Internal PIM is caused by the internal radio frequency (RF) elements in the radiating infrastructure, such as loose connectors, damaged cables and connectors, and faulty elements in the antennas. These issues typically occur between the transmitter and the antenna. Since internal PIM interference issues reside at the radio itself, a tower crew must climb to the top of the cell tower to perform troubleshooting. This can be extremely costly and time consuming.
Troubleshooting either internal or external PIM can be an expensive, manual process. When the issue involves internal PIM, a costly tower climb is usually required. Since there’s no guarantee the issue will be solved with an initial tower climb, a second climb may be required. In addition to being expensive, the entire process of finding and resolving an internal PIM issue can take weeks to complete. This is due in part to the required analysis, which is typically a 90% manual effort.