EIRP (Effective Isotropic Radiated Power) is the calculated power radiated by a transmitter, taking into account the antenna gain and cable losses. It represents the power that would be transmitted if the antenna were an ideal isotropic radiator, radiating equally in all directions. EIRP is typically expressed in dBm, which is a power ratio in decibels (dB) of the measured power referenced to one milliwatt (mW).