A system and method to perform fast transition time interval switching in an uplink multicarrier system. In one embodiment, an apparatus, and related method, is configured to receive a first user equipment power headroom (“UPH”) filtering value for a first uplink carrier from a user equipment, identify a measurement identifier with a first value for the first uplink carrier, and transmit the first UPH filtering value and the measurement identifier with the first value to a radio network controller.