Abstract
Due to the information explosion of internet, in recent years several new applications have been developed, such as video conferencing and distance learning. These applications often need to be built under the network structure that can offer the guaranteed quality of service. Traditionally, the guaranteed quality of service was obtained by doing a series of simulations by means of some heuristic algorithms under every specific network structure. It is becoming increasingly clear that traditional routing protocols are inadequate for these new applications which often have stringent quality of service （QoS）. Therefore, QoS is an important research area that has arrested much attention.In this thesis, we will focus on several problems on network design. Every theme has its specific request and necessary. At first, we will re-define each theme in detail. Then we will survey these problems in turn and propose a new problem mixed with some of problems. Finally, the conclusions and the future work of all problem will be discussed.