Method and Apparatus for Determining the Basis of a Triggered Power Headroom Report

A user equipment in a communication network, the user equipment comprising:

• a controller that detects an event triggering a power headroom report for a first activated serving cell has occurred;
• and
• a transceiver, coupled to the controller, that transmits the power headroom report on a first physical uplink shared channel transmission;
• wherein the controller identifies a first physical uplink shared channel resource corresponding to the first physical uplink shared channel transmission that comprises an initial transmission of a transport block since the power headroom report was triggered, and determines whether the first physical uplink shared channel resource corresponds to a configured grant or is in response to uplink grant downlink control information received on a physical downlink control channel since the power headroom report was triggered;
• and
• wherein the controller determines whether the power headroom report is based on an actual transmission or a reference format for each component carrier corresponding to respective downlink control information the user equipment receives until an expiration of a time window measured from the event.