在ns3中计算数据包接收时间

Question

我在ns3中的c ++中有以下代码，当收到数据包以打印其内容及其到达时间时使用

    Simulator::Now ().GetSeconds() 

但它每次都变成零。谁能告诉我为什么？我怎样才能获得实时？

Ptr<const Packet> p = packet;
LrWpanMacHeader h;
p->PeekHeader(h); //remove the header in order to print packet 
    content, so that's why the size differ between packet and p
    BasicPacketData bpd (p);
std::cout<<"Packet Size:"<<p->GetSize()<<std::endl;
uint8_t *buffer = new uint8_t[p->GetSize()];
p->CopyData (buffer, p->GetSize());
std::string receivedData(buffer, buffer+p->GetSize ());
std::cout<<"Received:"<<receivedData.c_str()<<std::endl;


if(!h.IsAcknowledgment()) //Returns true if the header is an ack
{

    NS_LOG_UNCOND ("----------Packet received----------\n"
            << "Packet of size " << bpd.size << " bytes received\n"
            << "on device with address "<< dev3->GetMac()->GetShortAddress()<<"\n"
            << "was sent from address " << dev->GetMac()->GetShortAddress() << "\n"
                           // << "on device with address "<< bpd.dst<<"\n"
            //<< "was sent from address " << bpd.src << "\n"
            << "sequence number is " << (int) bpd.seq_nr << "\n"
            << "PAN ID is " << bpd.pan_id << "\n"
                            <<"with time "<< " on time: " << Simulator::Now ().GetSeconds() <<    "s"
            << "----------Packet received------------\n\n"

    );

Answer 1

ns3 :: Packet :: Print方法用于打印数据包的内容：

https://www.nsnam.org/doxygen/classns3_1_1_packet.html#ad25486a838ac04533c83ff600d84546f

现在，您可能会看到零，因为数据包是使用由包含零的字节组成的虚拟有效负载进行初始化的。看到：

https://www.nsnam.org/doxygen/classns3_1_1_packet.html#a897aab15901dcf1f05f075db7b8d04b1