Information market for TV white space

We propose a novel information market for TV white space networks, where white space databases sell the information regarding the TV channel quality to unlicensed white space devices (WSDs). Different from the traditional spectrum market, the information market demonstrates the positive network externality, as more WSDs purchasing the information from a database will increase the value of the database's information to each of its buyers. We study an oligopoly information market, where two competitive databases compete to sell their information to WSDs, and WSDs decide whether and from which database to purchase the information. Specifically, we first derive the WSD's optimal purchasing behavior under fixed information prices, and show how the market share of each database dynamically evolves over time. We then characterize the market equilibrium, where no WSD has an incentive to change its purchasing behavior. Our analysis indicates that given the prices of databases, there may be multiple market equilibria, and which one actually emerges depends on the initial market shares of both databases. We further show that some equilibria are stable, in the sense that a small fluctuation on the equilibrium will drive the market back to the equilibrium, while some equilibria are not.