  We investigate a spectrum oligopoly where primary users allow secondary
access in lieu of financial remuneration. Transmission qualities of the
licensed bands fluctuate randomly. Each primary needs to select the price of
its channel with the knowledge of its own channel state but not that of its
competitors. Secondaries choose among the channels available on sale based on
their states and prices. We formulate the price selection as a non-cooperative
game and prove that a symmetric Nash equilibrium (NE) strategy profile exists
uniquely. We explicitly compute this strategy profile and analytically and
numerically evaluate its efficiency. Our structural results provide certain key
insights about the unique symmetric NE.
