"Minstrel-Blues" - Practical Joint Rate und Power Control in Linux mac80211 with todays 802.11b/g/a/n Chips

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One Line Summary

I will present the design, implemenation and performance imapct of my pratical joint rate and power control algorithm "Minstrel-Blues" within Linux mac80211 and IEEE 802.11 a/b/g/n Atheros chips.


Todays WiFi networks do only focus on rate control as adaptation to dynamic channel conditions. Transmit power control is
limited to a common power level with a rather fixed and high value for all outgoing packets. This leads to unnecessary high interference within the wireless network and therefore decreased overall network throughput. With Minstrel-Blues we introduce the first practical joint rate and power control algorithm in the Linus kernel. Its objective is to dynamically control the power levels of outgoing packets per communication link in such a way, that is tries to find the minimum power level needed to transmit with the same performance in terms of throughput. Our results show that in many cases we can significantly reduce transmission power levels while maintaining the same throughput per link and therefore reduce the overall interference within the network. The decreased level of interference give more transmission opportunities to other links (increased spatial reuse) and hence increases the sum network throughput. We have implemented our algorithm in Minstrel and Minstrel_HT at the mac80211 subsystem and adapted ath5k and ath9k to make use of a wide subset of Atheros chips that do provide fine grain power level settings per packet.


TPC, joint rate power control, 802.11h, mac80211

Presentation Materials