Common mode disturbance is generated by power electronics in all active devices. These are typically in the frequency range from 150 kHz to 30 MHz, though higher frequency disturbances are possible. These disturbances can be radiated and cause interference with wireless signals, or can become differential mode and be coupled into the upstream signal path of the cable plant, cause degradations to upstream signal-to-noise.
ANSI/SCTE 249 2018