  We investigate revenue maximization problems in auctions for dynamic spectrum
access. We consider the frequency division and spread spectrum methods of
dynamic spectrum sharing. In the frequency division method, a primary spectrum
user allocates portions of spectrum to different secondary users. In the spread
spectrum method, the primary user allocates transmission powers to each
secondary user. In both cases, we assume that a secondary user's utility
function is linear in the rate it can achieve by using the available
spectrum/power. Assuming strategic users, we present incentive compatible,
individually rational and revenue-maximizing mechanisms for the two scenarios.
