Cross-layer optimization in wireless data networks

互联网等数据网络传统上是以分层方式设计的，其中每一层仅通过预定义接口与其正上方和下方的层进行通信。分层架构也已为无线网络实施，主要是因为与传统有线网络的互操作性问题。然而，众所周知，由于无线介质的特定特性，即高误码率和大速率变化性，这种分层设计可能不适合无线网络，这会对更高层的网络协议产生负面影响。特别是，已经提出了跨不同协议层的一些交互可以显著提高无线系统的性能。

Data networks such as the Internet have traditionally been designed in a layered fashion where each layer communicates only with the layers directly above and below it through predefined interfaces. A layered architecture has also been implemented for wireless networks mainly because of inter-operability issues with legacy wireline networks. However, it is well known that such a layered design may not be appropriate for wireless networks due to the specific characteristics of wireless medium, i.e. high error rate and large rate variability, which can negatively impact higher layer network protocols. In particular, it has been suggested that some interactions across different protocol layers can significantly improve the performance of wireless systems.