Author
Pankaj Gandhi
India is home to one of the world’s fastest-growing and most dynamic mobile networks, with mobile subscriptions heading towards one billion and end-users demanding more bandwidth and capacity than ever. We are also seeing increased expectations for service levels and data usage rates.
Yet competition in the market compels us to keep capital expense (CapEx) and operating expense (OpEx) budgets under check even while addressing growth. This challenge drives operators towards better network performance management and optimal deployment of available resources. The limited availability of spectrum and spread across various bands further adds to challenges. One problem that grows hand in hand with network complexity is passive intermodulation, or PIM.
What is PIM and why is it an issue?
PIM gets created when wireless signals mix together. PIM can be generated in any circuit carrying more than one frequency whenever nonlinearity occurs. The greater the degree of nonlinearity, the greater the level of the PIM signal generated. PIM are harmonics of mixed frequencies that cause interference within the good signals in the network.
The consequence of PIM is a major impact on network performance and efficiency. PIM can cause the system to operate at maximum power instead of under power control, causing detrimental increased power dissipation in the components.
With India’s mobile data usage increasing at such rapid rates—3G use more than doubled in 2013 and 4G rollout is ongoing—network performance and reliability take on new levels of importance. The growing complexity of the network adds to the risk. Every new component along the radio frequency (RF) path can be a new cause of PIM. PIM becomes a significant concern in the network ecosystems as elements become more and more sensitive to ever smaller distortion levels.
PIM’s impact on the network performance, efficiency and capacity ultimately impacts on an organization’s bottom line.
To learn about identifying the causes of PIM and defending against it, see my complete post on ETTelecom’s TeleTalk blog. Network operators need to ensure that they safeguard their networks against PIM to deliver the quality of service that customers want. If you have any PIM questions, leave me a comment.
