Measurement of EMI on network cables due to multiple GSM phones

As the density of transmitters from mobile telecommunication systems continues to increase there is a greater risk of electromagnetic compatibility (EMC) problems due to the ensemble electromagnetic field from multiple mobile handsets. An analysis of the characteristics of the threat field from multiple handsets is presented allowing prediction of the statistics of the ensemble field. A measurement system designed to detect electromagnetic interference (EMI) from ensembles of cellular phones has been used to quantify the level of EMI on Ethernet cables from multiple global system for mobile communications (GSM) mobiles. The measurements are consistent with a simple statistical model of ensemble signals from GSM sources and electromagnetic modeling of the system.