By RAY BUTLER, CommScope -- In just a few short years, passive intermodulation (PIM) has gone from a vaguely understood but accepted nuisance to a major concern that wireless service providers seek to manage and minimize.
PIM’s rise in importance coincides with the increasing complexity of today’s wireless networks, including the use of higher orders of modulation and more frequency bands. As wireless service providers add the most recent 4G/long-term evolution (LTE) capabilities to their networks, the incidence and effects of PIM on performance and profitability are on the rise.
In the testing lab and among RF engineers, PIM is a key concern. Wireless service providers have been vigilant about establishing more stringent PIM standards. Many system vendors have created proactive processes and testing procedures to ensure these standards are being met, if not exceeded.
When it comes to field-testing by installers and services technicians, the awareness of PIM and how to properly detect it may not be as strong as it needs to be. Field testing for PIM introduces a number of additional variables that, if not properly accounted for, may result in wide-ranging discrepancies and inaccurate readings.
To offer wireless service providers and installers a better understanding of how PIM is created in today’s multilayered, highly sensitive network, CommScope has developed a new white paper called PIM Testing: Advanced wireless services emphasize the need for better PIM control. Readers of the white paper will learn how PIM’s rise in importance coincides with the increasing complexity of today’s wireless networks, as wireless service providers add the most recent 4G/LTE capabilities.
The document asks why the incidence and effects of PIM on network performance and profitability are on the rise, and offers tips on how providers and installers can better prepare. The paper also addresses how to accurately field test for PIM and neutralize the variables that may affect test results.
Ray Butler is vice president of research and development for the Active Wireless Products team at CommScope. Previously, Ray worked at Andrew Corporation as vice president of base station antennas; engineering; and systems engineering and solutions marketing, respectively. He has served as director of national RF engineering with AT&T Wireless and vice president of engineering, research and development, and international operations at Metawave Communications, a smart antenna company. Ray was technical manager of systems engineering for Lucent Technologies Bell Laboratories, having also held other management positions responsible for the design of RF circuits, filters and amplifiers. Ray holds a bachelor of science degree in electrical engineering from Brigham Young University and a master of science in electrical engineering from Polytechnic University.