Robust client-based Wi-Fi topology discovery

The low cost and ease of installation of Wi-Fi equipment operating in unlicensed spectrum have made dense Wi-Fi deployments a reality in most modern urban areas. With the lack of many non-overlapping frequencies to operate on, interference among neighbor Wi-Fi cells can cause significant performance degradation. Here we study the problem of topology discovery in such dense deployments, which is necessary in order to combat interference. To this end, we apply a client-driven scheme, where client devices sense the spectrum and report overlapping cells. However, reporting entities cannot always be assumed trustworthy. We therefore study cases where reporters attack the discovery process by submitting fake information and propose simple countermeasures to tackle some attacker strategies. We show analytically and via simulations that, in realistic urban scenarios, our mechanisms are effective, even in the presence of a large number of attackers.