甚高频数据链模式二协议栈的软件框架设计研究

Research on Software Structure Design of Very High Frequency Data Link Mode 2 Protocol Stack

为解决协议工作效率低下的问题,参考HDLC协议软件的设计方法,本文提出了甚高频数据链模式二(VDL M2)协议的软件模型和设计思想。首先,介绍了VDL M2协议栈的层次架构,并简要阐述了各层的功能。然后,介绍了协议栈的软件设计与实现方法,在不改变Linux内核现有地址族的前提下,创建基于本协议的新套接字地址族AF_VDLM2的操作。依据功能操作,软件结构确立为模块化结构布局；着重分析了协议栈数据收发模块的软件设计流程及缓冲区的结构设计。最后,介绍了协议层之间的通信方式——共享内存区的数据结构及创建和操作。用该方法设计的协议栈可方便地加载到机载通信单元,大大节省了设备成本。

In order to improve the work efficiency of protocol, with reference to the implementing method of HDLC protocol, the software model and the design concept of VDL M2 protocol stack were proposed. First, the layer structure of the VDL M2 protocol was introduced, and the function of each layer was briefly discussed. Next, the software design and implementation method of protocol stack were explained, namely on the precondition that the current address family in-core was not changed, a new socket address family AF_VDLM2 based on VDLM2 protocol set forward. According to the function operation, module-based structure was adopted. Then, the software design flow of receiving and dispatching module and the structure design of the buffer descriptor were emphasized. Finally, the communication mode among the layers was introduced, namely the data structure, establishment and operation of the shared memory field. The protocol stack may be load into aircraft CMU, and so facility cost would be significantly saved.