OMNeT++ ALOHA sample代码阅读

写在最前

前一篇博客谢了关于ALOHA的一些原理，现在看OMNeT++这个网络仿真软件的sample是如何实现ALOHA网络的。

代码

Server.ned

simple Server
{
    parameters:
        @display("i=device/antennatower_l");
        @signal[receiveBegin](type="long");  // increases with each new frame arriving to the server and drops to 0 if the channel becomes finally idle
        @signal[receive](type="long");  // for successful receptions (non-collisions): 1 at the start of the reception, 0 at the end of the reception
        @signal[collision](type="long"); // the number of collided frames at the beginning of the collision period
        @signal[collisionLength](type="simtime_t");  // the length of the last collision period at the end of the collision period
        @signal[channelState](type="long");

        //source 
        @statistic[serverChannelState](source="channelState";title="Channel state";enum="IDLE=0,TRANSMISSION=1,COLLISION=2";record=vector);
        @statistic[receiveBegin](source="receiveBegin"; record=vector?; interpolationmode=sample-hold; title="receive begin");
        @statistic[channelUtilization](source="timeavg(receive)"; record=last; interpolationmode=linear; title="channel utilization");
        @statistic[collisionMultiplicity](source=collision; record=vector?,histogram; title="collision multiplicity");
        @statistic[collisionLength](record=vector?,histogram,mean,sum,max; title="collision length");
        @statistic[receivedFrames](source="sum(receive)"; record=last; title="received frames");
        @statistic[collidedFrames](source="sum(collision)"; record=last; title="collided frames");
    gates:
        input in @directIn;
}

.ned文件一般是用于OMNeT中模块与仿真内核的配置，里面一般包含该模块的parameter，gates，connections等等。其中这里Server.ned文件中，开头定义了一些signal，主要是配合后面的statistic来使用，用于统计仿真过程中需要的统计指标（如时延，信道利用率等）。还定义了一个输入用的gate。

---

Server.h

//