Experimental characterization of 802.11n link quality at high rates

802.11n has made a quantum leap over legacy 802.11 systems by supporting extremely higher transmission rates at the physical layer. In this paper, we ask whether such high rates translate to high quality links in a real deployment. Our experimental investigation in an indoor wireless testbed reveals that the highest transmission rates advertised by the 802.11n standard typically produce losses (or even outages) even in interference-free environments. Such losses become more acute and persist at high SNR values, even at low interference intensity. We find that these problems are partly due to bad configurations that do not allow exploitation of spatial diversity, partly due to the wider 802.11n channels that expose these sensitive high rates to more interference. We show that these problems can be alleviated using the 802.11n MAC layer enhancements jointly with packet size adaptation.