  With more devices connected, delays and jitter at the WiFi hop become more
prevalent, and correct functioning during network congestion becomes more
important. However, two important performance issues prevent modern WiFi from
reaching its potential: Increased latency under load caused by excessive
queueing (i.e. bufferbloat) and the 802.11 performance anomaly.
  To remedy these issues, we present a novel two-part solution: We design a new
queueing scheme that eliminates bufferbloat in the wireless setting. Leveraging
this queueing scheme, we then design an airtime fairness scheduler that
operates at the access point and doesn't require any changes to clients.
  We evaluate our solution using both a theoretical model and experiments in a
testbed environment, formulating a suitable analytical model in the process. We
show that our solution achieves an order of magnitude reduction in latency
under load, large improvements in multi-station throughput, and nearly perfect
airtime fairness for both TCP and downstream UDP traffic. Further experiments
with application traffic confirm that the solution provides significant
performance gains for real-world traffic.We develop a production quality
implementation of our solution in the Linux kernel, the platform powering most
access points outside of the managed enterprise setting. The implementation has
been accepted into the mainline kernel distribution, making it available for
deployment on billions of devices running Linux today.
