For multimedia services over satellite networks, the efficient management of satellite downlink communications will be crucial due to the high cost of satellite transmission to many users with different quality of service (QoS) requirements and limited amount of onboard resources. An optimized design of the agile antenna multibeam pattern can improve the efficiency of transmission and power management. In this paper, we show the advantage of parallel multibeams in terms of spectral efficiency and power gain, and address the issue of multibeam power allocation based on traffic demands over satellite downlinks with power restriction. The analysis indicates that the use of a parallel multibeam scheme with optimized power splits can achieve a substantial power gain and reasonable proportional fairness. We also give a downlink multibeam scheduling solution when the number of beams is smaller than the number of cells, and show that a modest number of parallel beams are sufficient to obtain large power gains without need for many transmitters.