On the impact of 802.11n frame aggregation on end-to-end available bandwidth estimation
On the impact of 802.11n frame aggregation on end-to-end available bandwidth estimation
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802.11n帧聚合对端到端可用带宽估计的影响
DOI：
10.1109/sahcn.2014.6990333
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
Francisco J. Garcia
中科院分区：
文献类型：
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作者：
Arsham Farshad;Myungjin Lee;M. Marina;Francisco J. Garcia
我们首次在802.11n的背景下考虑可用带宽估计（ABE），它正在迅速取代传统的802.11a/b/g网络。实验表明，在影响ABE的802.11n特征中，帧聚合（FA）特征占主导地位。使用室内802.11n无线测试平台，我们在各种交叉流量场景中比较了三种ABE工具（WBest， DietTopp和pathChirp）。我们发现，FA显著损害了所有ABE工具的准确性；DietTopp和pathChirp相对来说比WBest更健壮。由于更快的可用带宽估计和更少的侵入性是任何ABE工具的理想特性，而WBest比其他两个工具更能满足这些特性，因此我们使用WBest对FA对ABE的有害影响进行了深入研究。这反过来又使我们提出了两个关键的设计原则来对抗FA效应：(1)将聚集探针视为一个巨型探针；(2)产生更多的探针。然后，我们开发了WBest的增强版本，称为WBest+，它包含了这些原则。我们的评估表明，在FA存在的情况下，新版本可以有效地实现准确的ABE。
We consider for the first time available bandwidth estimation (ABE) in the context of 802.11n, which is fast replacing the legacy 802.11a/b/g networks. We experimentally show that the frame aggregation (FA) feature of 802.11n is the dominant one among 802.11n features affecting the ABE. Using an indoor 802.11n wireless testbed, we compare three ABE tools (WBest, DietTopp and pathChirp) in various cross-traffic scenarios. We find that FA significantly hurts the accuracy of all ABE tools; DietTopp and pathChirp are relatively more robust than WBest. Because faster available bandwidth estimation and less intrusiveness are desirable properties of any ABE tool and WBest satisfies them relatively better than the other two tools, we conduct an in-depth investigation into the harmful effect of FA on ABE using WBest. This in turn led us to come up with two key design principles to counter FA effects: (1) treating aggregated probes as one jumbo probe; and (2) generating a larger number of probes. We then develop an enhanced version of WBest termed WBest+ that incorporates these principles. Our evaluation shows that the new version is effective in achieving accurate ABE in the presence of FA.