NIST has been engaged in the study of coexistence of the General Authorized Access (GAA) users in the Citizens Broadband Radio Service (CBRS) band. GAA users are the lowest priority users in the CBRS band. They must make sure that they do not cause harmful interference to the higher tier users while cooperating with each other to minimize potential interference among themselves. Towards this goal, the Wireless Innovation Forum (WInnForum) has recommended three schemes to facilitate GAA-GAA coexistence. NIST has published simulation based performance studies of two of these schemes that use real terrain and land cover data of continental USA.
NIST has studied dynamic spectrum access (DSA) for secondary users to exploit white spaces in LTE system. DSA algorithms based on Survival Analysis, that maximize white space utilization while limiting the interference to the primary user below a set threshold, have been designed for LTE systems. Real world LTE spectrum occupancy data were used to validate performance of the algorithms. Analytical model of white space utilization of a DSA system has also been carried out by applying theories from survival analysis and stochastic processes. Preliminary study based on machine learning using real-world LTE data for DSA also has been performed.
More details about GAA coexistence and DSA can be found in the references below: