NS3入门教程以及 NS3 IEEE 802.15.7 CSMA/CA仿真代码

待我称王封你为后i 2023-05-30 04:57 17阅读 0赞

本文初衷

当我发现我必须要做NS3网络仿真的时候，我内心是拒绝的，一方面NS3完全没接触过，另一方面，C++语言接触也不是太多，感觉工作量好大。但是，真的是不做不行了。然后，我就到网上查一些关于NS3的仿真内容，入门什么的，感觉真的是好混乱啊，这个东西没有一个明确的教程，都是一些杂乱的CSDN和技术博客，看起来十分混乱，而且有些现成的代码都是好多好多年前的，让人很难受。所以，我就写了本文，希望能对你有所帮助，静下心来从头往后看吧。

第一步 linux系统的使用

既然你已经准备好进行NS3仿真了，那么就先静下心来安装一个NS3吧，但是NS3都是运行在linux系统下的，所以，你先要安装一个linux系统。linux系统你可以直接安装到电脑上，当然你也可以使用linux虚拟机进行安装（我是在虚拟机上安装的），推荐的虚拟软件是VMware，这个软件可以创建一个虚拟机，就是可以创建一个虚拟的linux系统，这样你就可以不影响自己windows系统的情况下，轻松的使用NS3了，你可以百度一下VMware安装教程，也可以使用我下面的百度云链接进行下载安装。VMware的使用在这里就不赘述了，安装和使用还是比较容易的。

链接：https://pan.baidu.com/s/1vKbVrIKDqueMdywsYFzZqA  
提取码：crv1

第二步 NS3的安装

NS3的安装在网上有很多教程，可自行查找，我使用的版本是3.25

第三步 了解一下NS3开发流程

选择或开发相应模块：根据实际仿真对象和仿真场景选择相应的仿真模块：如果是有线局域网络（CSMA）还是无线局域网络（Wi-Fi）；节点是否需要移动（mobility）；使用何种应用程序（application）；是否需要能量（energy）管理；使用何种路由协议（internet、aodv等）；是否需要动画演示等可视化界面（visualizer、netanim）等。如果要搭建的网络是比较新的网络，如延迟容忍网络（DTN）等，需要开发设计协议，如路由协议、移动模型、能量管理模型等。

编写网络仿真脚本：有了相应的模块，就可以搭建网络仿真环境，ns3仿真脚本支持两种语言：C++和Python，但是两种语言的API接口是一样的，部分API可能还没有提供Python接口。编写ns3仿真脚本的大体过程如下。

1.  生成节点：ns3中节点相当于一个空的计算机外壳，接下来要给这个计算机安装网络所需要的软硬件，如网卡、应用程序、协议栈等。

1.  安装网络设备：不同的网络类型有不同的网络设备，从而提供不同的信道、物理层和MAC层，如CSMA、WiFi、WiMAX和point-to-point等。
2.  安装协议栈：ns3网络中一般是TCP/IP协议栈，依据网络选择具体协议栈，如是UDP还是TCP，选择何种不同的路由协议（OLSR、AODV和Global等）并为其配置相应的IP地址，ns3即支持IPv4也支持IPv6。
3.  安装应用层协议：依据选择的传输层协议选择相应的应用层协议，但有时需要自己编写应用层产生网络数据流量的代码。
4.  开始仿真。

其中节点，网络设备，信道，应用程序的基本概念可以参照下面的这个文章

[https://blog.csdn.net/weichanghu\_/article/details/83306998][https_blog.csdn.net_weichanghu_article_details_83306998]

第四步 了解一下NS3的时间调度机制

[https://blog.csdn.net/rustfree/article/details/84558058][https_blog.csdn.net_rustfree_article_details_84558058]

第五步 NS3官网给了first.cc点对点，CSMA和wifi 的示例

通过这个示例你就可以了解大概的一个开发流程了

[https://www.docin.com/p-2009136480.html][https_www.docin.com_p-2009136480.html]

第六步 NS3 API

这个时候NS3的大概框架应该掌握的差不多了，那么就可以试着看下面的代码了，然后这个文档里会定义一些NS3的一些特殊类，可以到这里查找，以及一些模型，也可以在这里查找，值得注意是，这个API有些古老，有些特性已经变了，比如随机指数变量的使用。

[https://www.nsnam.org/docs/release/3.7/doxygen/annotated.html][https_www.nsnam.org_docs_release_3.7_doxygen_annotated.html]

第七步 80215.7CSMA/CA的代码（仅供学习参考，不可全信，可能会有错误没有发现）

/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
    /*
     * This program is free software; you can redistribute it and/or modify
     * it under the terms of the GNU General Public License version 2 as
     * published by the Free Software Foundation;
     *
     * This program is distributed in the hope that it will be useful,
     * but WITHOUT ANY WARRANTY; without even the implied warranty of
     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     * GNU General Public License for more details.
     *
     * You should have received a copy of the GNU General Public License
     * along with this program; if not, write to the Free Software
     * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
     */
    //头文件包含，在h文件中进行函数声明，在cpp文件中完成函数的实现
    #include "ns3/core-module.h"
    #include "ns3/network-module.h"
    #include "ns3/internet-module.h"
    #include "ns3/point-to-point-module.h"
    #include "ns3/applications-module.h"
    //定义命名空间
    using namespace ns3;
    
    NS_LOG_COMPONENT_DEFINE ("MacCsma");
    
    class VLCNode;
    
    
    class VLCChannel{
    public:
    //这应该是一个类的初始化函数
    	VLCChannel(){
    		state=2;
    		ChannelSendTimeStamp=0;
    		ChannelCcaTimeStamp=0;
    //		AllPacketDelayPosition=0;
    		collisionTimes=0;
    		SumOfSuccessSendPackets=0;
    		AllPacketDelayVector.clear();
    	}
    	int state;     //1-busy,2-free,3-sleep
    	uint64_t ChannelSendTimeStamp;
    	uint64_t ChannelCcaTimeStamp;
    	uint64_t everySlotStartTimeStamp[16];
    	uint64_t collisionTimes;
    	EventId NextEndTxEventId;          //信道记录下一个结束发送事件ID，用于取消碰撞时先发送的数据包
    	int TheNodeIdOfNextEndTxEventId;    //下一个结束发送事件的节点ID号，用于告知已经发送的节点产生碰撞
    	VLCNode *nodes[20];          //数组下标为节点ID号
    
    	void SetBusy()
    	{
    		state=1;
    	}
    	void SetFree()
    	{
    		state=2;
    	}
    //	uint64_t AllPacketDelay[100000];      //统计所有数据包延时
    //	int AllPacketDelayPosition;         //插入延时信息位置
    
    	uint64_t SumOfSuccessSendPackets;   //所有成功传输的数据量之和
    	std::vector<uint64_t> AllPacketDelayVector;
    };
    
    class VLCNode{
    public:
    	VLCNode(){
    		opticalClockDuration=5000;
    		macMaxBE=5;
    		macMinBE=3;
    		NB=0;
    		BE=macMinBE;
    		macMaxRABackoffs=4;    //最大退避次数
    		oneBackoffTime=20*opticalClockDuration;      //the time of one backoff
    		rate=1000000;         //数据发送速率，对照协议MCSID取值不同设置
    		ackWaitDuration=20+240+103;      //  PHY II 是20+5120+103=5243；PHY III 是20+5120+111=5251
    //		macMaxFrameTotalWaitTime=10000000;   //不用
    
    
    		wasSuspend=false;
    		RandomAccessing=false;
    		NodeId=0;
    		numsOfCollision=0;
    		NumOfLostPackets=0;
    		NumsOfCCA=0;
    		NumsOfCCABusy=0;
    		NumsOfSendToChannel=0;
    	}
    	uint64_t NextSlotStartInterval(uint64_t timeStamp)
    	{
    		uint64_t result=0;
    		for(int i=0;i<16;i++)
    		{
    			if(timeStamp<(channel->everySlotStartTimeStamp[i]))
    			{
    				result=channel->everySlotStartTimeStamp[i]-timeStamp;
    				break;
    			}
    			else
    			{
    			}
    		}
    		return result;
    	}
    	void PacketCome(int packetSize)
    	{
    		NS_LOG_FUNCTION(this<<"NodeId"<<NodeId);
    		if(channel->state==3)
    		{
    //如果包来到的时候信道是不活跃状态，那么不进行随机接入函数调用，就先把包存到队列里就好了
    			packetSizeList.push_back(packetSize);
    			packetComeTimeStampList.push_back(Simulator::Now().GetNanoSeconds());
    		}
    		else
    		{
    			packetSizeList.push_back(packetSize);
    			packetComeTimeStampList.push_back(Simulator::Now().GetNanoSeconds());
    			if(!RandomAccessing)       
    //如果当前节点没有正在进行随机接入则开始，如果已经有随机接入，则等待随机接入完成再进行
    			{
    				startRandomAccess();
    			}
    		}
    	}
    	void startRandomAccess()
    	{
    		NS_LOG_FUNCTION(this<<"NodeId"<<NodeId);
    		RandomAccessing=true;
    		if(!packetSizeList.empty())   //packet list is not empty
    		{
    			NB=0;
    			BE=macMinBE;
    			uint64_t afterBeaconTime=0;    //距离本次超帧中的信标帧时长
    			afterBeaconTime=Simulator::Now().GetNanoSeconds()-channel->everySlotStartTimeStamp[0];
    			uint64_t remainTime=afterBeaconTime%((uint64_t)20*opticalClockDuration);  //remainTime是第一次时间对齐需要的时间，加上退避时间即第一次CCA需要继续等待的时间
    			Simulator::Schedule(NanoSeconds(remainTime),&VLCNode::firstBackoff,this);
    		}
    		else                  //packet list is empty
    		{
    //当包没有到来的时候，是什么也不执行的，等待packcome()函数再次调用
    		}
    	}
    	void firstBackoff()
    	{
    		NS_LOG_FUNCTION(this<<"NodeId is:"<<NodeId);
    //计算一下退避的时间，并在此时间后执行CCA过程
    		uint64_t backoffs=rand()%((int)pow(2,BE)-1);
    		uint64_t backoffTime=backoffs*oneBackoffTime;
    		CCABusyTimeStamp=Simulator::Now().GetNanoSeconds();
    		Simulator::Schedule(NanoSeconds(backoffTime),&VLCNode::CCA,this);
    	}
    	void CCA()
    	{
    		backoffTime=0;
    		NS_LOG_FUNCTION(this<<"NodeId"<<NodeId<<"channelState"<<channel->state);
    		uint64_t CcaInterval=Simulator::Now().GetNanoSeconds()-channel->ChannelCcaTimeStamp;
    		NumsOfCCA++;     //统计节点进行CCA总次数
    		if(CcaInterval<1000)   //CCA 时间间隔小于1000ns，认为碰撞发生
    		{
    			NumsOfSendToChannel++;
    			collision();
    		}
    		else                //未发生碰撞正常执行CCA
    		{
    
    			NodeCcaTimeStamp=Simulator::Now().GetNanoSeconds();
    			channel->ChannelCcaTimeStamp=NodeCcaTimeStamp;
    			if(channel->state==1)   //channel is busy: nums of backoff ++
    			{
    				NB++;
    				BE++;
    				NumsOfCCABusy++;      //统计检测信道忙总次数
    				if(BE>macMaxBE)
    				{
    					BE=macMaxBE;
    				}
    				else
    				{
    				}
    //			NS_LOG_DEBUG("the NB is :"<<NB<<"the macMaxRABackoffs is"<<macMaxRABackoffs);
    				if(NB>=macMaxRABackoffs)
    				{
    					failure();               //failure
    				}
    				else
    				{
    					CCABusyTimeStamp=Simulator::Now().GetNanoSeconds();
    //					uint64_t remainSlotTime=NextSlotStartInterval(Simulator::Now().GetNanoSeconds());       //确定距离下一个时隙时间差
    					uint64_t backoffs=rand()%((int)pow(2,BE)-1);
    					backoffTime=backoffs*oneBackoffTime;
    					CCAEvent=Simulator::Schedule(NanoSeconds(backoffTime),&VLCNode::CCA,this);
    				}
    
    			}
    
    			else if(channel->state==2)   //channel is free : send
    			{
    
    				NumsOfSendToChannel++;
    				//recieve ack time
    				uint64_t getAckTime=(rand()%ackWaitDuration+400)*opticalClockDuration;  //接收到ACK的时间,400是长帧间间隔
    				ACKAndIFSDuration=getAckTime;
    				uint64_t thePacketSizeWithHeader=packetSizeList.front()+4+8;
    				double onlyDataDuration=(double)thePacketSizeWithHeader*8*1000000000/(double)rate;
    //				NS_LOG_DEBUG("onlyDataDuration is:"<<onlyDataDuration);
    //				NS_LOG_DEBUG("getAckTime is:"<<getAckTime);
    				uint64_t txDuration=onlyDataDuration+getAckTime;
    				NodeSendTimeStamp=Simulator::Now().GetNanoSeconds();//节点开始发送时间戳
    				channel->ChannelSendTimeStamp=NodeSendTimeStamp;//信道开始发送时间戳
    			   EndTxEvent=Simulator::Schedule(NanoSeconds(txDuration),&VLCNode::endTx,this);
    				channel->TheNodeIdOfNextEndTxEventId=NodeId;
    				channel->NextEndTxEventId=EndTxEvent;
    				channel->state=1;    //set channel is busy
    			}
    		}
    	}
    
    	void endTx()
    	{
    		NS_LOG_FUNCTION(this<<"NodeId"<<NodeId);
    		RandomAccessing=false;
    		if(channel->state==1)    //信道状态等于发送时设置的忙
    		{
    			if(NodeSendTimeStamp!=channel->ChannelSendTimeStamp)
    			{
    				collision();
    			}
    			else
    			{
    				channel->state=2;
    				if(!packetComeTimeStampList.empty())
    				{
    					uint64_t delay=Simulator::Now().GetNanoSeconds()-packetComeTimeStampList.front();
    //					NS_LOG_INFO("the delay with ack and LIFS is ："<<delay);
    //					NS_LOG_INFO("the delay without ack and LIFS is :"<<delay-ACKAndIFSDuration);
    //					channel->AllPacketDelay[channel->AllPacketDelayPosition]=delay-ACKAndIFSDuration;
    //					channel->AllPacketDelayPosition++;
    
    					channel->AllPacketDelayVector.push_back(delay-ACKAndIFSDuration);
    				}
    				if(!packetSizeList.empty())
    				{
    					uint64_t PacketSize=packetSizeList.front();//统计所有成功发送数据包
    					channel->SumOfSuccessSendPackets=channel->SumOfSuccessSendPackets+PacketSize;
    					packetSizeList.pop_front();
    					packetComeTimeStampList.pop_front();
    				}
    				else
    				{
    				}
    				if(!packetSizeList.empty())
    				{
    					startRandomAccess();
    				}
    			}
    		}
    		else if(channel->state==2)                 //信道状态被其他节点修改为空闲，发生碰撞
    		{
    			collision();
    		}
    		else                   //信道由超帧设置为休眠
    		{
    
    		}
    
    	}
    	void isNotifiedCollision()
    	{
    		NS_LOG_FUNCTION(this<<"NodeId"<<NodeId);
    //		numsOfCollision++;
    		channel->collisionTimes++;            //信道中记录所有节点碰撞次数
    		NB++;
    		BE++;
    		if(BE>macMaxBE)
    		{
    			BE=macMaxBE;
    		}
    		else
    		{
    		}
    //		NS_LOG_DEBUG("the NB is :"<<NB<<"the macMaxRABackoffs is"<<macMaxRABackoffs);
    		if(NB>=macMaxRABackoffs)
    		{
    			failure();	             //failure
    		}
    		else
    		{
    //			CCABusyTimeStamp=Simulator::Now().GetNanoSeconds();
    			uint64_t thePacketSizeWithHeader=packetSizeList.front()+4+8;
    			double onlyDataDuration=(double)thePacketSizeWithHeader*8*1000000000/(double)rate;
    			uint64_t sendDuration=onlyDataDuration+ackWaitDuration;
    			Simulator::Schedule(NanoSeconds(sendDuration),&VLCChannel::SetFree,channel);   //被告知碰撞，在预期的接收ACK时间到达后将信道设置为空闲
    //			uint64_t remainSlotTime=NextSlotStartInterval(Simulator::Now().GetNanoSeconds()+sendDuration);
    			uint64_t backoffs=rand()%((int)pow(2,BE)-1);
    			backoffTime=backoffs*oneBackoffTime;
    			CCAEvent=Simulator::Schedule(NanoSeconds(sendDuration+backoffTime),&VLCNode::CCA,this);
    		}
    	}
    	void collision()
    	{
    		NS_LOG_FUNCTION(this<<"NodeId"<<NodeId);
    //		NS_LOG_INFO("collison");
    //		EndTxEvent.Cancel();
    
    		channel->NextEndTxEventId.Cancel();
    //		NS_LOG_DEBUG("the channel->TheNodeIdOfNextEndTxEventId:"<<channel->TheNodeIdOfNextEndTxEventId);
    		channel->nodes[channel->TheNodeIdOfNextEndTxEventId]->isNotifiedCollision();
    //		channel->nodes[channel->TheNodeIdOfNextEndTxEventId]->collision();
    //		channel->AllPacketDelayPosition--;
    
    //		channel->AllPacketDelayVector.pop_back();
    		numsOfCollision++;
    		NB++;
    		BE++;
    		if(BE>macMaxBE)
    		{
    			BE=macMaxBE;
    		}
    		else
    		{
    		}
    //		NS_LOG_DEBUG("the NB is :"<<NB<<"the macMaxRABackoffs is"<<macMaxRABackoffs);
    		if(NB>=macMaxRABackoffs)
    		{
    			failure();	             //failure
    		}
    		else
    		{
    			CCABusyTimeStamp=Simulator::Now().GetNanoSeconds();
    			uint64_t thePacketSizeWithHeader=packetSizeList.front()+4+8;
    			double onlyDataDuration=(double)thePacketSizeWithHeader*8*1000000000/(double)rate;
    			uint64_t sendDuration=onlyDataDuration+ackWaitDuration;
    			Simulator::Schedule(NanoSeconds(sendDuration),&VLCChannel::SetFree,channel);   //碰撞发生后，在预期的接收ACK时间到达后将信道设置为空闲
    //			uint64_t remainSlotTime=NextSlotStartInterval(Simulator::Now().GetNanoSeconds()+sendDuration);
    			uint64_t backoffs=rand()%((int)pow(2,BE)-1);
    			backoffTime=backoffs*oneBackoffTime;
    			CCAEvent=Simulator::Schedule(NanoSeconds(backoffTime),&VLCNode::CCA,this);
    		}
    	}
    	void failure()
    	{
    		NS_LOG_FUNCTION(this<<"NodeId"<<NodeId);
    //		NS_LOG_INFO("one packet failure,NodeId"<<NodeId);
    		NumOfLostPackets++;
    		RandomAccessing=false;
    		if(!packetSizeList.empty())
    		{
    			packetSizeList.pop_front();
    			packetComeTimeStampList.pop_front();
    		}
    		else
    		{
    		}
    		if(!packetSizeList.empty())
    		{
    			startRandomAccess();
    		}
    	}
    	void suspend()
    	{
    		NS_LOG_FUNCTION(this<<"NodeId"<<NodeId);
    		CCAEvent.Cancel();
    		wasSuspend=true;
    		CAPRestartAccessBackofftime=Simulator::Now().GetNanoSeconds()-CCABusyTimeStamp;
    	}
    	void CAPRestartAccess()
    	{
    		NS_LOG_FUNCTION(this<<"NodeId"<<NodeId);
    		if(wasSuspend)       
    //如果之前被中断，则根据剩余退避时间退避，也就是重新恢复之前的接入过程
    		{
    			wasSuspend=false;
    			Simulator::Schedule(NanoSeconds(CAPRestartAccessBackofftime),&VLCNode::CCA,this);
    		}
    		else  //如果之前没有被中断，则看数据队列是否为空,非空则发起随机接入算法
    		{
    			if(!packetSizeList.empty())
    			{
    				startRandomAccess();
    			}
    		}
    	}
    	int NB;
    	int BE;
    	int macMaxBE;
    	int macMinBE;
    	int macMaxRABackoffs;
    	int oneBackoffTime;      //the time of one backoff
    //	int macMaxFrameTotalWaitTime;
    
    	uint64_t CCABusyTimeStamp;
    	uint64_t backoffTime;       //退比时长
    	EventId CCAEvent;
    	EventId EndTxEvent;
    	uint64_t CAPRestartAccessBackofftime;   //下一个超帧开始，随机介入重启需要退避时间
    	bool wasSuspend;                         //是否因为超帧结束导致CCA延迟，true是，false否
    	int NumOfLostPackets;               //超过最大退避次数，失败
    	bool RandomAccessing;               //true-正在进行随机接入过程，进入休眠需要suspend
    	int NodeId;
    	int numsOfCollision;
    	int NumsOfCCA;
    	int NumsOfCCABusy;
    	int NumsOfSendToChannel;
    	uint64_t NodeSendTimeStamp;
    	uint64_t NodeCcaTimeStamp;
    	uint64_t ACKAndIFSDuration;             //发送结束后帧间间隔和ACK花费时间
    
    	uint64_t rate;
    	uint64_t ackWaitDuration;
    	int opticalClockDuration;
    	std::deque<uint64_t> packetSizeList;
    	std::deque<uint64_t> packetComeTimeStampList;
    	VLCChannel *channel;
    };
    class SuperFrame{
    public:
    	SuperFrame(){
    		BO=9;
    		SO=8;
    		state=true;        //true-active,false-sleep
    		opticalClockDuration=5000;
    		aBaseSuperframeDuration=60*16;
    	}
    	void start()
    	{
    		NS_LOG_FUNCTION(this);
    //将superframe状态设置为true，这个状态表示活跃态CAP，false表示不活跃态sleep
    //此CSMA代码不包含CFP阶段
    		state=true;
    //将信道设置为空闲，信道状态分为三个，1忙碌，2空闲，3睡眠sleep，就是上面的不活跃态
    		channel->state=2;
    //调用下面的方法，开始CAP阶段
    		CAPToSleep();
    	}
    	void CAPToSleep()       //CAP start
    	{
    		NS_LOG_FUNCTION(this<<"CAP Start");
    		state=true;
    		channel->state=2;
    
    //		channel->state=1;    //测试信道条件一直忙
    
    		uint64_t SD=aBaseSuperframeDuration*pow(2,SO)*opticalClockDuration;
    		uint64_t aSlotDuration=SD/16;
    		uint64_t nowTime=Simulator::Now().GetNanoSeconds();
    //		NS_LOG_DEBUG("nowTime="<<nowTime);
    //		NS_LOG_DEBUG("SD="<<SD);
    //		NS_LOG_DEBUG("aSlotDuration="<<aSlotDuration);
    //一共有十六个时隙，所以要循环16次，根据信标beacon时间，定位接下来每一帧的开始时间
    		for(int i=0;i<16;i++)
    		{
    			channel->everySlotStartTimeStamp[i]=nowTime+aSlotDuration*i;
    //			NS_LOG_DEBUG("everySlotStartTimeStamp"<<channel->everySlotStartTimeStamp[i]);
    		}
    //			NS_LOG_DEBUG("CAP duration"<<SD);
    //定义一个节点迭代器，对节点进行迭代
    		std::vector<VLCNode *>::iterator it;
    //每个节点执行CAP重传接入，可跳到CAPRestartAccess阅读
    		for(it=m_Nodes.begin();it!=m_Nodes.end();it++)
    		{
    			(*it)->CAPRestartAccess();
    		}
    		Simulator::Schedule(NanoSeconds(SD),&SuperFrame::SleepToCAP,this);
    
    	}
    	void SleepToCAP()       //start Sleep
    	{
    		NS_LOG_FUNCTION(this<<"Start Sleep");
    		state=false;
    
    		std::vector<VLCNode *>::iterator it;
    		for(it=m_Nodes.begin();it!=m_Nodes.end();it++)
    		{
    			if((*it)->RandomAccessing)
    			{
    				(*it)->suspend();
    			}
    		}
    
    		channel->state=3;
    		uint64_t SD=aBaseSuperframeDuration*pow(2,SO)*opticalClockDuration;
    		uint64_t BI=aBaseSuperframeDuration*pow(2,BO)*opticalClockDuration;
    		uint64_t SleepTime=BI-SD;
    //		NS_LOG_DEBUG("Sleep duration"<<SleepTime);
    		Simulator::Schedule(NanoSeconds(SleepTime),&SuperFrame::CAPToSleep,this);
    	}
    
    	int BO;
    	int SO;
    	bool state;        //true-active,false-sleep
    	int aBaseSuperframeDuration;
    	int opticalClockDuration;
    	std::vector<VLCNode *>  m_Nodes;
    	VLCChannel *channel;
    };
    
    int allPacketNums=0;
    void testAddPacket(VLCNode *nodeId,int packetSize)
    {
    	nodeId->packetSizeList.push_back(packetSize);
    	nodeId->packetComeTimeStampList.push_back(Simulator::Now().GetNanoSeconds());
    }
    void DelayMean(VLCChannel *channel)
    {
    	double sum=0;
    	double mean=0;
    	for(unsigned int i=0;i<channel->AllPacketDelayVector.size();i++)
    	{
    		sum=sum+channel->AllPacketDelayVector.at(i);
    	}
    	mean=(double)sum/(channel->AllPacketDelayVector.size());
    	NS_LOG_INFO("the delay Mean="<<mean<<",nums of packet="<<allPacketNums);
    	NS_LOG_INFO("the num of node1 failure:"<<channel->nodes[1]->NumOfLostPackets);
    	NS_LOG_INFO("the num of node2 failure:"<<channel->nodes[2]->NumOfLostPackets);
    	NS_LOG_INFO("the num of collision:"<<channel->collisionTimes);
    	NS_LOG_INFO("the Throughput is:"<<(channel->SumOfSuccessSendPackets+12)*8/Simulator::Now().GetSeconds());
    	NS_LOG_INFO("node 1 Probability of collision:"<<(float)(channel->nodes[1]->numsOfCollision)/(float)(channel->nodes[1]->NumsOfSendToChannel));
    	NS_LOG_INFO("node 2 Probability of collision:"<<(float)(channel->nodes[2]->numsOfCollision)/(float)(channel->nodes[2]->NumsOfSendToChannel));
    	NS_LOG_INFO("node 3 Probability of collision:"<<(float)(channel->nodes[3]->numsOfCollision)/(float)(channel->nodes[3]->NumsOfSendToChannel));
    	NS_LOG_INFO("node 4 Probability of collision:"<<(float)(channel->nodes[4]->numsOfCollision)/(float)(channel->nodes[4]->NumsOfSendToChannel));
    	NS_LOG_INFO("node 5 Probability of collision:"<<(float)(channel->nodes[5]->numsOfCollision)/(float)(channel->nodes[5]->NumsOfSendToChannel));
    	NS_LOG_INFO("node 6 Probability of collision:"<<(float)(channel->nodes[6]->numsOfCollision)/(float)(channel->nodes[6]->NumsOfSendToChannel));
    	NS_LOG_INFO("node 7 Probability of collision:"<<(float)(channel->nodes[7]->numsOfCollision)/(float)(channel->nodes[7]->NumsOfSendToChannel));
    	NS_LOG_INFO("node 8 Probability of collision:"<<(float)(channel->nodes[8]->numsOfCollision)/(float)(channel->nodes[8]->NumsOfSendToChannel));
    	NS_LOG_INFO("node 9 Probability of collision:"<<(float)(channel->nodes[9]->numsOfCollision)/(float)(channel->nodes[9]->NumsOfSendToChannel));
    	NS_LOG_INFO("node 10 Probability of collision:"<<(float)(channel->nodes[10]->numsOfCollision)/(float)(channel->nodes[10]->NumsOfSendToChannel));
    
    //	float SumPofCollision=(float)(channel->nodes[1]->numsOfCollision)/(float)(channel->nodes[1]->NumsOfSendToChannel)+
    //			(float)(channel->nodes[2]->numsOfCollision)/(float)(channel->nodes[2]->NumsOfSendToChannel)+
    //			(float)(channel->nodes[3]->numsOfCollision)/(float)(channel->nodes[3]->NumsOfSendToChannel)+
    //			(float)(channel->nodes[4]->numsOfCollision)/(float)(channel->nodes[4]->NumsOfSendToChannel)+
    //			(float)(channel->nodes[5]->numsOfCollision)/(float)(channel->nodes[5]->NumsOfSendToChannel);
    	int j=0;
    	float SumPofCollision=0;
    	for(int i=1;i<11;i++)
    	{
    		if((channel->nodes[i]->NumsOfSendToChannel)!=0)
    		{
    			SumPofCollision=SumPofCollision+(float)(channel->nodes[i]->numsOfCollision)/(float)(channel->nodes[i]->NumsOfSendToChannel);
    			j++;
    		}
    	}
    
    	float PofCollision=SumPofCollision/(float)(j);
    	NS_LOG_INFO("P of Collision:"<<PofCollision);
    
    	NS_LOG_INFO("node 1 Probability of CCABusy:"<<(float)(channel->nodes[1]->NumsOfCCABusy)/(float)(channel->nodes[1]->NumsOfCCA));
    	NS_LOG_INFO("node 2 Probability of CCABusy:"<<(float)(channel->nodes[2]->NumsOfCCABusy)/(float)(channel->nodes[2]->NumsOfCCA));
    	NS_LOG_INFO("node 3 Probability of CCABusy:"<<(float)(channel->nodes[3]->NumsOfCCABusy)/(float)(channel->nodes[3]->NumsOfCCA));
    	NS_LOG_INFO("node 4 Probability of CCABusy:"<<(float)(channel->nodes[4]->NumsOfCCABusy)/(float)(channel->nodes[4]->NumsOfCCA));
    	NS_LOG_INFO("node 5 Probability of CCABusy:"<<(float)(channel->nodes[5]->NumsOfCCABusy)/(float)(channel->nodes[5]->NumsOfCCA));
    	NS_LOG_INFO("node 6 Probability of CCABusy:"<<(float)(channel->nodes[6]->NumsOfCCABusy)/(float)(channel->nodes[6]->NumsOfCCA));
    	NS_LOG_INFO("node 7 Probability of CCABusy:"<<(float)(channel->nodes[7]->NumsOfCCABusy)/(float)(channel->nodes[7]->NumsOfCCA));
    	NS_LOG_INFO("node 8 Probability of CCABusy:"<<(float)(channel->nodes[8]->NumsOfCCABusy)/(float)(channel->nodes[8]->NumsOfCCA));
    	NS_LOG_INFO("node 9 Probability of CCABusy:"<<(float)(channel->nodes[9]->NumsOfCCABusy)/(float)(channel->nodes[9]->NumsOfCCA));
    	NS_LOG_INFO("node 10 Probability of CCABusy:"<<(float)(channel->nodes[10]->NumsOfCCABusy)/(float)(channel->nodes[10]->NumsOfCCA));
    
    //	float SumPofCCABusy=(float)(channel->nodes[1]->NumsOfCCABusy)/(float)(channel->nodes[1]->NumsOfCCA)+
    //			(float)(channel->nodes[2]->NumsOfCCABusy)/(float)(channel->nodes[2]->NumsOfCCA)+
    //			(float)(channel->nodes[3]->NumsOfCCABusy)/(float)(channel->nodes[3]->NumsOfCCA)+
    //			(float)(channel->nodes[4]->NumsOfCCABusy)/(float)(channel->nodes[4]->NumsOfCCA)+
    //			(float)(channel->nodes[5]->NumsOfCCABusy)/(float)(channel->nodes[5]->NumsOfCCA);
    	float SumPofCCABusy=0;
    	for(int i=1;i<=j;i++)
    	{
    		SumPofCCABusy=SumPofCCABusy+(float)(channel->nodes[i]->NumsOfCCABusy)/(float)(channel->nodes[i]->NumsOfCCA);
    	}
    
    
    	float PofCCABusy=SumPofCCABusy/(float)(j);
    	NS_LOG_INFO("P of CCABusy:"<<PofCCABusy);
    
    	std::ofstream out("5NodeWithMean.txt",std::ios::app);
    	out<<(channel->SumOfSuccessSendPackets+12)*8/Simulator::Now().GetSeconds()<<" "
    			<<PofCollision<<" "<<PofCCABusy<<std::endl;
    
    }
    //void TestCapPacketCome(VLCNode *node,SuperFrame *superFrame)
    //{
    //	if(superFrame->state)
    //	{
    //		node->PacketCome(500);
    //	}
    //}
    //*****************************************************************problem******************************************************************************
    void PacketExponentialCome(VLCNode *node,double mean)
    {
    	double nextPacketComeInterval;
        Ptr<ExponentialRandomVariable> interval=CreateObject<ExponentialRandomVariable>();
        double bound=40.0;
        interval->SetAttribute("Mean",DoubleValue(mean));
        interval->SetAttribute("Bound",DoubleValue(bound));
        nextPacketComeInterval=interval->GetValue();
    //	if(node->channel->state!=3)
    //	{
    		allPacketNums++;
    		node->PacketCome(100);
    //	}
    	Simulator::Schedule(Seconds(nextPacketComeInterval),&PacketExponentialCome,node,mean);
    }
    //这是CSMA代码的主函数
    int
    main (int argc, char *argv[])
    {
    
    	long int mean=1;
    	CommandLine cmd;
    	cmd.AddValue("mean","the mean packet",mean);
    	cmd.Parse(argc,argv);
    
      Time::SetResolution (Time::NS);
    
      RngSeedManager::SetSeed(time(0));
    
      LogComponentEnable ("MacCsma", LOG_LEVEL_INFO);
      LogComponentEnable("MacCsma", LOG_PREFIX_TIME);
    
    
      uint64_t opticalClockDurationValue;
      opticalClockDurationValue=5000;
    
      SuperFrame superFrame;
      superFrame.opticalClockDuration=opticalClockDurationValue;
      VLCChannel channel;
    
      VLCNode node1;
      node1.NodeId=1;
      node1.opticalClockDuration=opticalClockDurationValue;
      VLCNode node2;
      node2.NodeId=2;
      node2.opticalClockDuration=opticalClockDurationValue;
      VLCNode node3;
      node3.NodeId=3;
      node3.opticalClockDuration=opticalClockDurationValue;
      VLCNode node4;
      node4.NodeId=4;
      node4.opticalClockDuration=opticalClockDurationValue;
      VLCNode node5;
      node5.NodeId=5;
      node5.opticalClockDuration=opticalClockDurationValue;
      VLCNode node6;
      node6.NodeId=6;
      node6.opticalClockDuration=opticalClockDurationValue;
      VLCNode node7;
      node7.NodeId=7;
      node7.opticalClockDuration=opticalClockDurationValue;
      VLCNode node8;
      node8.NodeId=8;
      node8.opticalClockDuration=opticalClockDurationValue;
      VLCNode node9;
      node9.NodeId=9;
      node9.opticalClockDuration=opticalClockDurationValue;
      VLCNode node10;
      node10.NodeId=10;
      node10.opticalClockDuration=opticalClockDurationValue;
    
    
    
      node1.channel=&channel;
      node2.channel=&channel;
      node3.channel=&channel;
      node4.channel=&channel;
      node5.channel=&channel;
      node6.channel=&channel;
      node7.channel=&channel;
      node8.channel=&channel;
      node9.channel=&channel;
      node10.channel=&channel;
    
      channel.nodes[1]=&node1;
      channel.nodes[2]=&node2;
      channel.nodes[3]=&node3;
      channel.nodes[4]=&node4;
      channel.nodes[5]=&node5;
      channel.nodes[6]=&node6;
      channel.nodes[7]=&node7;
      channel.nodes[8]=&node8;
      channel.nodes[9]=&node9;
      channel.nodes[10]=&node10;
    
    
      superFrame.channel=&channel;
      superFrame.m_Nodes.push_back(&node1);
      superFrame.m_Nodes.push_back(&node2);
      superFrame.m_Nodes.push_back(&node3);
      superFrame.m_Nodes.push_back(&node4);
      superFrame.m_Nodes.push_back(&node5);
      superFrame.m_Nodes.push_back(&node6);
      superFrame.m_Nodes.push_back(&node7);
      superFrame.m_Nodes.push_back(&node8);
      superFrame.m_Nodes.push_back(&node9);
      superFrame.m_Nodes.push_back(&node10);
    
    
    //此时，调用superframe的start方法，让它先运行起来，但是此时，包还没来，
    //startrandomaccess（）方法没有什么可执行的，跳到了start（）方法继续阅读。
      superFrame.start();
    
      double exponentialMean=0.005;
      std::ofstream out("NodeChanges.txt",std::ios::app);
      	out<<exponentialMean<<" ";
      	out.flush();
    
    //当运行到相应时间的时候，各个节点陆续有包到达了，开始正常的竞争接入随机接入过程
      Simulator::Schedule(Seconds(3.1),&PacketExponentialCome,&node1,exponentialMean);
      Simulator::Schedule(Seconds(4.5),&PacketExponentialCome,&node2,exponentialMean);
      Simulator::Schedule(Seconds(3.5),&PacketExponentialCome,&node3,exponentialMean);
      Simulator::Schedule(Seconds(3.8),&PacketExponentialCome,&node4,exponentialMean);
      Simulator::Schedule(Seconds(3.4),&PacketExponentialCome,&node5,exponentialMean);
      Simulator::Schedule(Seconds(4.6),&PacketExponentialCome,&node6,exponentialMean);
      Simulator::Schedule(Seconds(4.2),&PacketExponentialCome,&node7,exponentialMean);
      Simulator::Schedule(Seconds(4.7),&PacketExponentialCome,&node8,exponentialMean);
      Simulator::Schedule(Seconds(3.3),&PacketExponentialCome,&node9,exponentialMean);
      Simulator::Schedule(Seconds(3.9),&PacketExponentialCome,&node10,exponentialMean);
    
    
    //  	  Simulator::Schedule(Seconds(3.1),&VLCNode::PacketCome,&node1,500);
    //  	  Simulator::Schedule(Seconds(3.3),&VLCNode::PacketCome,&node2,600);
    
    //  Simulator::Schedule(Seconds(2.4999),&testAddPacket,&node1,500);
    //  Simulator::Schedule(Seconds(2.4999),&testAddPacket,&node2,600);
    //  Simulator::Schedule(Seconds(2.5),&VLCNode::CCA,&node1);
    //  Simulator::Schedule(Seconds(2.5),&VLCNode::CCA,&node2);
    //预定执行到499秒的时候，执行以下delaymean方法，这个方法是输出前面统计结果的一个函数
    //在最终结束之前，将所有结果输出到屏幕上
      Simulator::Schedule(Seconds(499),&DelayMean,&channel);
    //预定一个停止的时间，为500秒，这里的时间是一个虚拟的时间，比真实的时间更快
      Simulator::Stop(Seconds(500));
    //进入死循环，如果没有stop上面方法的约束，会一直执行下去
      Simulator::Run ();
    //释放资源
      Simulator::Destroy ();
      return 0;
    }

[https_blog.csdn.net_weichanghu_article_details_83306998]: https://blog.csdn.net/weichanghu_/article/details/83306998
[https_blog.csdn.net_rustfree_article_details_84558058]: https://blog.csdn.net/rustfree/article/details/84558058
[https_www.docin.com_p-2009136480.html]: https://www.docin.com/p-2009136480.html
[https_www.nsnam.org_docs_release_3.7_doxygen_annotated.html]: https://www.nsnam.org/docs/release/3.7/doxygen/annotated.html