Patent ID: 9419768
Filing Date: 2016-08-16
CPC Classification: H04L,H04W

Claim Text:
1. A method of transmitting a power headroom report by a user equipment in a communication system supporting carrier aggregation, the user equipment being configured with a plurality of serving cells including a primary cell and at least one secondary cell, the method comprising: determining, by the user equipment, maximum transmission powers of the user equipment for the plurality of serving cells; calculating, by the user equipment, power headroom for the plurality of serving cells using respective maximum transmission powers determined for the plurality of serving cells; and transmitting, by the user equipment to a base station, the power headroom report for the plurality of serving cells, wherein the power headroom report includes first two consecutive bytes including: wherein the power headroom report further includes an indication field for each of the at least one secondary cell, wherein, based on the indication field indicating that the power headroom report includes power headroom for a specific secondary cell of the at least one secondary cell, the power headroom report further includes second two consecutive bytes including: wherein, based on the indication field indicating that the power headroom report does not include the power headroom information for the specific secondary cell of the at least one secondary cell, the second two consecutive bytes are skipped in the power headroom report, and wherein a power headroom for a cell is calculated based on a difference between a maximum transmission power determined for the cell and a transmission power configured for the cell.