Wireless reliability: Rethinking 802.11 packet loss

Wireless enabled devices are ubiquitous in todaypsilas computing environment. Businesses, universities, and home users alike are taking advantage of the easy deployment of wireless devices to provide network connectivity without the expense associated with wired connections. Unfortunately, the wireless medium is inherently unreliable resulting in significant work having been performed to better understand the characteristics of the wireless environment. Notably, many works attribute the primary source of wireless losses to errors in the physical medium. In contrast, our work shows that the wireless device itself plays a significant role in 802.11 packet loss. In our experiments, we found that the correlation of loss between multiple closely located (within one lambda) receivers is low with the majority of loss instances only occurring at one of the receivers. We conducted extensive experiments on the individual loss characteristics of five common wireless cards, showing that while the cards behave similarly on the macro-level (e.g. similar overall loss rates), the cards perform quite differently on the micro-level (e.g. burstiness, correlation, and consistency).