A system, apparatuses and methods are provided for communicating in an opportunistic band. Channels that are reserved for primary users are used by sensing devices when primary users are not present. A geo-location database is configured to store occupancy information of a channel and information associated with the primary user of the channel. The database includes information such as the type of primary user, and the expected occupancy time of a channel by a primary user. Sensing devices are categorized into different classes based on their sensing capability. A device capabilities database stores device classification information associated with the sensing devices attached to a dynamic spectrum management system.