Johnny Appleseed

Abstract

Many areas have dense deployments of 802.11 wireless access points, often with little or no planning of the best choices of channel assignments. As a result, there is often very high interference due to poor channel assignments. One contributing factor is that many access points are deployed with the absolute minimum of configuration effort, which means they are assigned to the channel the manufacturer has chosen, as a default. In many cases, such minimal effort deployments also mean that the access point uses the manufacturer-default password. Inspired by Johnny Appleseed, a 19th century American altruist who wandered the wilderness planting apple trees for the use of others, we investigate a method by which an altruistic wardriver moving through a dense wireless deployment could take advantage of such minimally configured access points. Where possible, he could use the default passwords to log into the system and change the channel assignment to better suite the surrounding environment, reducing interference for all. We examine this solution in simulation using real data gathered by wardrivers in several locations. We demonstrate that even with some conservative assumptions on the number of access points our Johnny Appleseed could alter, simple single-pass algorithms can result in a 10% reduction of total interference in a dense wireless deployment. We discuss the legal and ethical implications of the approach.