Line sweeping is a quality measure of the transmission lines and/or antenna system. Systems may include cables, connectors, lightning protectors, tower mounted amplifiers, and antennas (Figure: Cable and Antenna Line Sweeping). Line sweeping can measure the power losses in the system at the functional frequencies and measures system impedance and confirms whether the system meets carrier specifications.

If the system does not meet specification, line sweeping can also locate components that are reflecting power above specified levels.