Spectrum sharing using licensed shared access: The concept and its workflow for LTE-Advanced networks

Spectrum sharing between an existing incumbent spectrum user and an LTE/LTEAdvanced network with conditions that resemble exclusive licensing have become an appealing solution for mobile network operators to respond to the growing traffic and spectrum demand in a timely manner. While traditional exclusive licensing continues to be the preferred option for MNOs, the new sharing-based licensed shared access (LSA) concept is receiving growing interest in research, regulation and standardization. When applied to mobile communications, the LSA concept would allow an MNO to share spectrum from another type of incumbent spectrum user under a regulator's supervision with predetermined rules and conditions that guarantee operational certainty for both MNO and incumbent. This article reviews different types of spectrum bands for LTE/LTE-Advanced and beyond networks, and focuses on the LSA concept as a spectrally efficient solution for spectrum access in the future. The article identifies the key stakeholders, including the incumbent spectrum user, the MNO, and the regulator, and their roles in the LSA concept. The key elements in the LSA concept are reviewed, and a work flow for the life cycle of the LSA concept is proposed, consisting of LSA preparation, licensing, deployment, and release phases. The tasks of the key stakeholders in the different phases of the LSA work flow are discussed. The LSA concept can offer a complementary approach to traditional exclusive licensing and license-exempt operations with features that benefit all involved stakeholders. It can be realized with reasonable modifications to the existing network infrastructure and regulatory framework with two new elements for managing the varying spectrum availability: the LSA Repository and LSA Controller