中文摘要：

网络编码的核心思想是允许网络节点对传输信息进行编码处理，运用网络编码能够提升网络吞吐量、均衡网络负载和提高网络带宽利用率等。介绍了网络编码的几种主要算法和机制，并对这些算法在提高网络QoS性能方面进行了仿真和比较研究。

英文摘要：

The critical idea for network coding is coding information in medium nodes. The application of network coding can improve network throughput, balance network load and improve bandwidth utilization ratio. Several main network coding algorithms are introduced in this paper. Simulations are done for these algorithms in comparing their network QoS performance.