A mobile wireless terminal (MWT) includes multiple wireless modems. The multiple modems have their respective transmit outputs combined to produce an aggregate transmit output. The multiple modems can concurrently transmit data in a reverse link direction and receive data in a forward link direction. The MWT is constrained to operate under an aggregate transmit power limit. Each of the multiple modems has an individual transmit limit related to the aggregate transmit power limit. An MWT controller controls the total number of modems that transmit data at any given time, based on an average energy-per-transmitted bit, or alternatively, individual energy-per-transmitted bits of the modems.