Ht and Vht duration is not correctly computed and the simulation throw a failure if separateReceptionParts = true

[aarizaq]

The total duration is computed using only the preamble and the data, the physical header is not considered.

virtual const simtime_t getDuration(b dataBitLength) const override { return preambleMode->getDuration() + dataMode->getDuration(dataBitLength); }

But in the radio model we have this
const simtime_t preambleDuration = transmissionMode->getPreambleMode()->getDuration();
const simtime_t headerDuration = transmissionMode->getHeaderMode()->getDuration();
const simtime_t dataDuration = duration - headerDuration - preambleDuration;

dataDuration is a negative value

Possible solution
aarizaq@b3239b8