Development of a measurement system for spectrum awareness

Dynamic spectrum access (DSA) is an attractive approach to solve the spectrum scarcity problem. Among DSA techniques, spectrum overlay is an approach where the spectrum licensed to a primary user (PU) is shared by a secondary user (SU) while protecting the PU from interference. In the case where PU traffic is dynamic, spectrum sharing is difficult as awareness of the instantaneous spectrum state is required at the SU. To find out the current spectrum state, spectrum sensing techniques have been proposed. However, it is very difficult to satisfy the challenging accuracy, quickness and low cost requirements in practice. For this issue, we propose a new concept of smart spectrum access (SSA) where statistical information of PU spectrum utilization is used to achieve the above requirements. We also show an approach to realize practical SSA and it consists of a spectrum awareness system (SAS) and a dynamic spectrum access system (DSAS). In this paper, we present a framework for smart spectrum access and discuss the challenges of this approach. In addition, we report some of the investigation results related to SAS.