Bugzilla – Bug 2514
The maximum transmission time for VHT A-MPDUs is not correct
Last modified: 2016-10-01 22:41:06 UTC
Created attachment 2600 [details] Patch to fix The maximum transmission time, which is used to decide whether a new MPDU can be aggregated in an existing A-MPDU (see MacLow::StopMpduAggregation), is different for HT and VHT PPDUs. In HT, the maximum duration is 10ms (current value in the code). However, in VHT the maximum duration should be 5.484ms (see IEEE 802.11ac-2013 Table 22-29 — VHT PHY characteristics).
I would like to take this one for ns-3.26 release, could have have feedback asap? Thanks!
Another possibility is to initialize aPPDUMaxTime to 10 ms, and to decrease it if VHT is in use, and then to simplify the if statement as: if ((m_phy->CalculateTxDuration (aggregatedPacket->GetSize () + peekedPacket->GetSize () + peekedHdr.GetSize () + WIFI_MAC_FCS_LENGTH, m_currentTxVector, preamble, m_phy->GetFrequency ()) > aPPDUMaxTime)) Also, does this patch change any regression test results?
(In reply to Tom Henderson from comment #2) > Another possibility is to initialize aPPDUMaxTime to 10 ms, and to decrease > it if VHT is in use, and then to simplify the if statement as: > > if ((m_phy->CalculateTxDuration (aggregatedPacket->GetSize () + > peekedPacket->GetSize () + peekedHdr.GetSize () + WIFI_MAC_FCS_LENGTH, > m_currentTxVector, preamble, m_phy->GetFrequency ()) > aPPDUMaxTime)) > > Also, does this patch change any regression test results? I am ok with your suggestion. It does not affect any test.
Reworked patch pushed in changeset 12358:f577cc35732a