  TV White Spaces have recently been proposed as an alternative to alleviate
the spectrum crunch, characterised by the need to reallocate frequency bands to
accommodate the ever-growing demand for wireless communications. In this paper,
we discuss the motivations and challenges for collecting spectrum measurements
in developing regions and discuss a scalable system for communities to gather
and provide access to White Spaces information through open and regionalised
repositories. We further discuss two relevant aspects. First, we propose a
cooperative mechanism for sensing spectrum availability using a detector
approach. Second, we propose a strategy (and an architecture) on the database
side to implement spectrum governance. Other aspects of the work include
discussion of an extensive measurement campaign showing a number of white
spaces in developing regions, an overview of our experience on low-cost
spectrum analysers, and the architecture of zebra-rfo, an application for
processing crowd-sourced spectrum data.
