Database-aided distributed channel assignment in spectrum sharing

Databases have been considered in the context of spectrum sharing systems to collect information on spectrum usage by primary users and to provide information on spectrum opportunities to secondary users. We develop a database-aided distributed channel assignment protocol (CAP) for secondary access control in a spectrum sharing system. Based upon a slotted, multichannel random access system model, we describe several secondary CAPs with varying levels of information from the database. We analyze handshake performance within a single slot based upon a given number of secondary users and a limited number of available channels, and we study the system transient performance for reaching steady state. System throughput and delay are also derived based on the number of secondary users and available channels. Finally, we propose dynamic channelization within the system bandwidth based upon the number of secondary users to maximize throughput.