Protect Your Wireless Network from PIM

Lou Meyer August 12, 2014

Tower ClimberNo wireless operator can afford to ignore pervasive and system-wide problems that impact network performance—especially those that will only get worse over time as networks become more complex. One such disruptive problem that continues to grow is passive intermodulation (PIM).

PIM results when two or more wireless signals mix together and create disruptive frequencies that cause interference or degrade signal transmission in wireless networks. This common phenomenon is well known in the industry and recognized by RF engineers as a real obstacle to network efficiency.

Because data usage is on the rise and network antennas and radios are more sensitive than ever to smaller levels of distortion, PIM incidents and their negative impact will become more prevalent. For example, even a one decibel drop in uplink sensitivity due to PIM can reduce coverage by 11 percent. Adding to the problem is network complexity, with each component in the RF path representing a potential source of PIM.

PIM is a huge challenge for network operators with the potential to impact efficiency, capacity and the bottom line. What measures can be taken to thwart this growing concern? What are the technical considerations—and the specific areas, components and conditions—that can cause PIM? Can site design or even installation factors cause PIM? Most importantly, what can you do to minimize PIM in today’s congested, multi-signal environment?

These questions are all addressed in my new white paper, Technical Keys to Successful Network Modernization: PIM. This is the third white paper in our new series about specific network modernization topics. The first one was about FTTA (Fiber to the Antenna) and the last one was about ultra-wideband antennas. If you want to learn even more about PIM, go to our PIM Site Audit and Avoidance webpage where many PIM resources are gathered, including system calculators, another white paper and more.

If you have further questions, leave me a comment.

About the Author

Lou Meyer

Louis Meyer, P.E., is director of technical sales for CommScope Mobility Solutions. Lou has spent a lifetime advancing RF technology, taking it from the drawing board to practical use. Over the years—in various roles with Allen Telecom, Andrew Ltd. and CommScope—Lou has been responsible for supporting the sales teams for such solutions as remote antenna control systems, transmission lines, diplexers and other important components. Prior to joining Allen Telecom, Lou worked with Decibel Products as vice president of Antenna Design and vice president of International OEM Relations. Earlier, Lou worked with Harris Corporation in RF communications and Bendix Corporation in their Missile Systems division. Lou holds 10 patents and was previously chair and vice-chair of the TIA’s TR-8.11 Antenna Standards subcommittee. He earned his Bachelor of Science degree in electrical engineering from Marquette University in Milwaukee, Wisconsin, and is currently a registered professional engineer in the state of Texas.