F5/unison
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

wifi: Update documentation on WifiMacQueue

Browse Source
This commit is contained in:
Tom Henderson
2023-08-20 16:32:31 -07:00
parent 04cae66175
commit a51637b644
2 changed files with 14 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

10
src/wifi/doc/source/wifi-design.rst
View File

@@ -965,6 +965,16 @@ assigned a User Priority based on the socket priority (see, e.g., the wifi-multi
the wifi-mac-ofdma examples), which determines the Access Category that handles the
packet. By default, wifi MAC queues support flow control, hence upper layers do not
forward a packet down if there is no room for it in the corresponding MAC queue.
Wifi MAC queues do not support dynamic queue limits (byte queue limits); therefore,
there is no backpressure into the traffic control layer until the WifiMacQueue for
an access category is completely full (i.e., when the queue depth reaches the value
of the MaxSize attribute, which defaults to 500 packets).
TCP small queues (TSQ) [corbet2012]_ is a Linux feature that provides feedback from the
Wi-Fi device to the socket layer, to control how much data is queued at the Wi-Fi
level. |ns3| TCP does not implement TSQ, nor does the WifiNetDevice provide that
specific feedback (although some use of the existing trace sources may be enough to
support it). Regardless, experimental tests have demonstrated that TSQ interferes with
Wi-Fi aggregation on uplink transfers [grazia2022]_.
Packets stay in the wifi MAC queue until they are acknowledged or discarded. A packet
may be discarded because, e.g., its lifetime expired (i.e., it stayed in the queue for too
long) or the maximum number of retries was reached. The maximum lifetime for a packet can

4
src/wifi/doc/source/wifi-references.rst
View File

@@ -64,3 +64,7 @@ References
.. [magrin2021mu] \ D. Magrin, S. Avallone, S. Roy, and M. Zorzi, 'Validation of the ns-3 802.11ax OFDMA implementation', in Proceedings of WNS3 2021.
.. [avallone2021wcm] \ S. Avallone, P. Imputato, G. Redieteab, C. Ghosh and S. Roy, "Will OFDMA Improve the Performance of 802.11 WiFi Networks?", in IEEE Wireless Communications Magazine, DOI: 10.1109/MWC.001.2000332, to appear.
.. [corbet2012] \ J. Corbet, "TCP Small Queues", `LWN.net, July 17, 2012 <https://lwn.net/Articles/507065/>`__
.. [grazia2022] \ C. Grazia, N. Patriciello, T. Hoiland-Jorgensen, M. Klapez and M. Casoni, "Aggregating Without Bloating: Hard Times for TCP on Wi-Fi", IEEE/ACM Transactions on Networking, Vol. 30, No.5, October 2022.