To PIM or not to PIM
By deploying its LTE network mobile operators are facing a new problem: PIM (passive intermodulation)
This problem occurs because operators combine into a single antenna system its 3G technology with the new LTE (4G) and this produces interferences which affect the reception of the LTE. Because users increasingly use LTE in applications that do not tolerate quality problems such as WhatsApp and video streaming, operators feel more and more pressure to resolve this.
Many operators follow blind instructions given by the manufacturers of LTE for characterization of PIM and these in turn order contractors to make such measurements but the contractors will bend over backwards as soon as they learn that to make these tests they must invest in expensive and heavy equipment such PIM Testers that only work in a single band which prevents them from using the devices in other contracts with other operators.
But what must be understood is that a characterization does not solve the problems of PIM. The characterization is intended to simulate the conditions of PIM to prevent it, but in our region it is likely that when you characterize nothing happens and then PIM becomes present when the cell starts operating in LTE.
It is therefore that we suggest operators and contractors not to buy these PIM Testing devices but with a simple Spectrum Analyzer and a simple procedure will solve the problems of PIM during the whole operation after the cell is in service.