This Recommendation specifies the electromagnetic compatibility requirements and the test methods for equipment that use the low-voltage A.C. power line as the transition medium for the purpose of monitoring and control applications, the communication would be normally between phase to phase and using a frequency range 0.5 MHz to 12 MHz . E.M. environment was classified into different categories in consideration of the dedicated transformer used or not, the cabling buried or ariel, the far away to residential dwellings, and for each category the Emission limits and measurement methods as well as the immunity test levels is specified in the Recommendation.