Note: Eighth in a series on Energy Solutions 

In the past, when wireless operators needed additional capacity, they simply built more cell sites or added more equipment to their current sites. 

Today, we know now this approach is inefficient and unpractical for three reasons:

  • Tower space is limited

  • Adding new sites is costly

  • The capital/operational investments cannot be justified on limited budgets 

As the demand for mobile data continues unabated, operators are overlaying new wireless technologies like HSPA+ or LTE to existing tower infrastructure. They are also taking steps to avoid potential signal degradation that can result from these overlays, especially while they are adding new frequency bands. One major concern is passive intermodulation (PIM) noise—one of the biggest contributors to poor cell site capacity. PIM management has become a top priority for wireless operators. Let’s take a closer look at PIM. 


It is the result of two or more wireless signals mixing together creating additional, undesired frequencies that causes interference or degraded transmission of desired signals. PIM has long been recognized as an obstacle to network efficiency and engineers have acknowledged its existence and disruption potential. 

PIM is also a major concern for next generation networks such as LTE, because it is easier to disrupt data signals where subscribers experience poor quality. Antennas and radios are now hypersensitive, susceptible to smaller levels of distortion. A 1dB drop in uplink sensitivity because of PIM reduces coverage by 11 percent. Meanwhile, there are more components than ever in the RF path; each additional component is another potential source of PIM. 

It is a fact that when you can improve PIM, you improve data throughput. This, in turn, helps improve capacity and conserve energy. Furthermore, if you can improve the capacity of your current cell site, you can reduce energy costs by eliminating the need for additional towers and radios. 

At CommScope, we work with our customers and advise them on how to minimize the impact of PIM and improve their cell site capacity. A comprehensive PIM program focusing on awareness, prevention, identification, resolution and support is offered to our customers. Recently, PIM audits and optimizations resulted in one customer improving throughput by as much as six times—eliminating the need for, and cost of, adding more cell sites. 

How can CommScope help you proactively minimize and eliminate PIM wherever possible?

About the Author


Anil K. Trehan is Vice-president of Energy Solutions, for CommScope, a global leader in infrastructure solutions for communications networks. In this position, he is responsible for development of new energy products and solutions for the telecommunications carrier market, including wireless and wireline service providers. Mr. Trehan has presented on energy savings solutions at various international conferences and trade shows. He has four patents and eight patent pending applications to his credit. In his 25 years of work experience, he has held several technical management and engineering positions at Avaya, Lucent Technologies, AT&T – Bell Labs, and General Electric. Mr. Trehan has a masters and bachelors degree in Engineering.

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