Distributed LSA controller for public safety communications

Public safety scenarios require rapid means to set up communication networks into locations without working infrastructure or reserved radio spectrum. In this paper, we propose a new architectural concept for licensed shared access (LSA). The distributed architecture enables rapid deployment of public safety networks and efficient cooperation with commercial mobile networks. We have built a novel distributed LSA controller (DLC) to control spectrum sharing. We focus on reducing the configuration time at a base station which is one of the most time-consuming factors in the LSA system. The evacuation process aims to protect the incumbent spectrum users' rights by evacuating LSA band when the band requested from the incumbent is received. The frequency change process, on the other hand, defines the necessary time for a base station to start their service in a new LSA band from the time the base station received a new frequency band information from the LSA repository. We measure time in both processes to show the influence of the new concept in overall system performance. The results clearly show that configuration time reduces significantly by own new approach. The demonstration shows that the new concept is suitable for public safety communications working with existing commercial mobile networks and that it can also be applied to other licensed sharing techniques with the minimum amount of new components.