High-speed wireless backbones: measurements from MagNets

The long-standing vision of ubiquitous Internet access requires high-speed wireless networks that sustain 100 Mbps or more. While existing hardware already supports these speeds and they are available at single access points, measurement studies of existing mesh or multi-hop WiFi networks that cover and span larger areas report effective throughputs that are one or two orders of magnitude lower. We ask the question whether we can not already build high-speed wireless network that sustain high rates. To answer this question, we have built the MagNets high-speed WiFi backbone in the heart of Berlin. This paper presents an experimental evaluation of the single and multi-hop performance in terms of throughput, jitter, delay, packet loss, and assesses the impact of environmental factors on these parameters. Our results indicate, e.g. that some links achieve a sustained UDP throughput of up to 62 Mbps using off-the-shelf hardware supporting Super-AG modes, whereas others are limited to 4–5 Mbps due to interfering networks. In contrast, we show that the link performance is largely unaffected by environmental factors, such as day/night or social events (i.e. 2006 FIFA World Cup semi-final and final matches).