Increasing demand for high data rate applications, such as multimedia services and mobile TV over wireless ad hoc networks, urges researchers to develop more flexible network protocols in order to meet various Quality of Service (QoS) requirements. Unfortunately, the traditional strict layering design approach is no longer effective in wireless ad hoc networks, particularly in the mobile ad hoc networks, and fails to achieve the desired flexibility. Thus, cross-layer network design becomes much more important than ever and should be investigated thoroughly. In this project, the PI carefully selects three research tasks ? joint design of flow/congestion control and medium access control, active collaborative relaying, and opportunistic medium access control and auto rate control ? to demonstrate how cross-layer design should be done and how this design could improve the performance. In all these problems, the medium access control (MAC) layer acts as the anchor point to extract the needed information about the wireless environment to be used for other layers. In so doing, network protocols can be made more adaptive and responsive. It is expected that cross-layer design methodology can be significantly advanced through this research. Moreover, the basic ideas and the cross-layer design methodology introduced in this research open a new avenue to the design of efficient network protocols and the proposed technologies could be easily incorporated into the commercial products, and hence will have significant economic impact on the telecommunication industries. Finally, any research outcome of cross-layer design can be easily incorporated into wireless network courses that train the future work force.
