title: Computing End-To-End Delay in Veins
body: <p>I have read a bunch of posts on SO regarding the computation of end-to-end delay in Veins, but have not found an answer to be fulfilling in explaining why the delay is seemingly too low. </p>
  
  <p>I am using:</p>
  
  <ul>
  <li>Veins 4.7</li>
  <li>Sumo 0.32.0</li>
  <li>Omnetpp 5.3</li>
  </ul>
  
  <p>Channel switching is turned off.</p>
  
  <p>I have the following code, sending a message from the transmitting node:</p>
  
  <pre><code>if(sendMessage) {
    WaveShortMessage* wsm = new WaveShortMessage();
    sendDown(wsm);
  }
  </code></pre>
  
  <p>The receiving node computes the delay using the wsm creation time, but I have also tried setting the timestamp on the transmitting side. The result is the same.</p>
  
  <pre><code>simtime_t delay = simTime() - wsm -&gt; getCreationTime();
  delayVector.record(delay);
  </code></pre>
  
  <p>The sample output for the delay vector is as follows:</p>
  
  <p>Item#   Event#  Time             Value<br>
  0       165     14.400239402394  2.39402394E-4<br>
  1       186     14.500240403299  2.40403299E-4<br>
  2       207     14.600241404069  2.41404069E-4<br>
  3       228     14.700242404729  2.42404729E-4  </p>
  
  <p>Which means that the end-to-end delay (from creation to reception) is equivalent to roughly a quarter of a millisecond, which seems to be quite low - and a fair bit below what is typically reported in the literature. This seems to be consistent with what other people have reported as being an issue (e.g. <a href="https://stackoverflow.com/questions/32044168/end-to-end-delay-in-veins">end to end delay in Veins</a>)</p>
  
  <p>Am I missing something in this computation? I have tried adding load on the network by adding a high number of vehicular nodes (21 nodes within a 1000x50 sandbox on a straight highway, with an average speed of 50 km/h), but the result seems to be the same. The difference is negligible. I have read several research papers that suggest that end-to-end delay should increase dramatically in high vehicular densities.</p>