A wireless base unit (102) supporting carrier aggregation determines a truncation time period (159, 169) in order to create a reduced subframe component (154, 164) on an additional component carrier (120) such that the truncated subframe component (154, 164) does not interfere with the control region (171, 172) of a subframe (170, 180) transmitted on an overlapping component carrier (130) by an uncoordinated second base unit (105). The wireless base unit (102) transmits the truncated subframe component (154, 164) and also transmits truncation time period information within a control region (151, 161) of an anchor carrier (110). A remote terminal (104, 108) that supports carrier aggregation searches a control region (151, 161) of a subframe (150, 160) transmitted on the anchor carrier (110) for truncation information and uses the truncation information to determine a boundary of a data region in a subframe component (154, 164) received on the additional component carrier (120).