Analysis of requirements from standardization for Licensed Shared Access (LSA) system implementation

Licensed Shared Access (LSA) is a novel flexible regulatory framework, which introduces a shared licensed use of a spectrum band to complement the existing exclusively licensed and license-exempt use. LSA as a general concept was first introduced by the European Commission already in 2011 and it has gained growing interest in standardization and regulatory forums in Europe since. To highlight its potential, European regulators have recently recognized LSA as a promising approach to provide mobile network operators (MNOs) access to the 2.3-2.4 GHz band. In this case, the protection of incumbent users introduces new requirements for information exchange between the incumbents and the mobile network. European Telecommunications Standards Institute's (ETSI) Reconfigurable Radio Systems (RRS) group has defined the requirements, which the LSA system needs to fulfil in order to enable mobile access to the 2.3-2.4 GHz band. This paper places LSA in the regulation and standardization landscape and presents a comprehensive overview of the activities in all relevant forums including their interrelations, to demonstrate the development of the concept. It specifically focuses on the standardization requirements on the LSA system, analyzes and maps the requirements from the ETSI RRS into the different functional blocks of the LSA architecture, and envisions how these can be taken into account in the system implementation. While the incumbent protection places a large number of new requirements on the mobile system design, the LSA system implementation is seen to be feasible by utilizing the existing LTE and LTE-Advanced features, and by developing the required new functionalities according to the standardization requirements.