A method of measuring a total radiated power of a device under test by a test system with a base station simulator, a measurement antenna assigned to the base station simulator and a control and/or measurement equipment is described. The method includes: establishing a radio resource control connection between the device under test and the base station simulator via the measurement antenna; activating an uplink-beam lock function at the device under test; and performing a total radiated power measurement by the control and/or measurement equipment while continuously sending a downlink signal from the base station simulator via the measurement antenna to the device under test. A test system is further described.