An Evolution Toward Cognitive Cellular Systems: Licensed Shared Access (LSA) For Network Optimization

This paper reviews the application of the recent European Licensed Shared Access (LSA) concept for spectrum sharing between a mobile network operator (MNO) and an incumbent spectrum user. LSA as a new application area of cognitive technology provides the MNO an opportunity to take into use new frequency resources on a shared basis. This paper discusses the critical design criteria in LSA from the MNO point of view for the future cognitive cellular networks that can efficiently exploit shared spectrum bands. We describe the role of LSA bands in the heterogeneous networking context and identify the Long Term Evolution (LTE) and LTE-Advanced enabling technologies supporting the introduction of LSA including e.g. traffic steering, carrier aggregation and self-organizing networking. Additionally, we introduce an LSA management unit controlled by the MNO to be implemented on top of the existing LTE/LTE-Advanced architecture and discuss the required functionalities for the optimization and automation of LSA band management. We also depict the interrelations of the tasks of the LSA management unit and the supporting LTE/LTE-Advanced technologies. The on-going cellular evolution is shown to form a solid base for the introduction of new shared spectrum bands for cognitive cellular systems.?