Efficient spectrum sharing with autonomous primary users: Distributed dynamic spectrum leasing (D-DSL)

In this paper we introduce a new architecture for dynamic spectrum sharing called the distributed dynamic spectrum leasing (D-DSL) and a game theoretic framework for its implementation on a cognitive radio network. In D-DSL, it is assumed that each channel is assigned to a primary user who may lease the channel to secondary users. The spectrum owners can thus dynamically adjust the amount of interference they are willing to tolerate from the secondary users. The secondary users compete with each other in order to achieve maximum possible Quality of Service without violating the interference cap imposed by the primary users on each channel. The secondary users are allowed to transmit in more than one channel simultaneously. The utility of each primary user is in general an increasing function of the amount of allowed secondary interference. Under these conditions in addition to the competition among secondary users, the primary users also compete with each other to let more secondary users to access their channels. We establish conditions for the system to reach an equilibrium and analyze the performance. It is shown that the performance of the secondary system improves by increasing the availability of primary channels.