In telecommunications, and particularly in radio, signal strength is the measure of how strong a signal is. Typically, this is measured as voltage per square area. Higher power uses such as broadcasting use units of millivolts per square metre (mV/m²). Very low-power uses are most often in microvolts per square metre (µV/m²).
Expressed in decibels, 1mV/m² is 0dBm (a shortened dB(mV/m²)), or 60dBµ (often written dBu).
