What is PIM testing?
Passive InterModulation (PIM) is one of today’s most critical measurements in wireless telecom applications. With high throughput expectations for their devices users constantly push current networks to their limit. Newer LTE networks feature increased mobile data rates and this higher transmission rate exposes PIM vulnerabilities in today’s networks like never before. Good network PIM performance and PIM testing are now imperative for all network operators if they want to retain customer loyalty
Figure 1 (below) shows an example of an operator needing to keep PIM signals below the LTE noise floor limit of -121 dBm.
It should be noted that PIM signals exist as a result of the combined transmission of multiple carrier frequencies within a transmission line path. The objective is to ensure that these levels, by design and in practice, should occur at an amplitude which is below the base stations receiver sensitivity. The amplitude of these undesired signals is directly influenced by the fidelity of the transmission line path, including all components and junctions that can introduce a non-linear effect to the signals passing through them.
In order to represent real-traffic network conditions PIM testing measurements must be made at the base station radio power level or higher. PIM tests that are performed at low power can mask the presence of passive intermodulation in the network. The ability to exceed the current 20W specification gives operators much more measurement confidence and with UMTS and LTE carrier power levels likely to be specified at 40W the ability for PIM testing at these levels will become mandatory.
GWI offers high power PIM test services with complete reporting using the latest equipment from major manufacturers including CCI. GWI Telecom personnel are also outfitted with all approved safety gear. Each of our teams is trained and certified on the CCI, Anritsu and Kaelus PIM Testers. We are always in demand and “on-call” for you. We can deploy our teams 24 hours a day, seven days a week and be anywhere in Ontario within hours. We can cover many other provinces as well. Documentation is provided in chart or reports form for reference and analysis. Custom sweep testing and documentation is also available.