On the broadband Internet communication, the service quality is a very important item on the multimedia. Three examples listed below will best make this clear. (1) The real time interactive video performs on the network communication. (2) The on line playing game executed on the mobile platform. (3) The multipoint-to-multipoint files download based on the mobile platform. If the narrow bandwidth limited was happen from a network layer to a physical layer through a media access control. Then the poor symbol rate will decrease the performance of the overall communication. In this paper, a well match cross layer approach is proposed. It can overcome the shortcomings mentioned above and increase the performance of the overall communication. Besides, it can improve the digital modulation efficiencies of physical layer. The proposed method can be applied to all communication systems.