Considerations on the Licensed Shared Access (LSA) Architecture from the Incumbent Perspective

Abstract

As the amount of mobile data continues to grow rapidly, finding frequency bands without incumbent usage for mobile network operators (MNOs) in a harmonized manner becomes increasingly challenging. This motivates the search for new methods to increase the efficiency of current spectrum usage by exploring the new possibilities to allow multiple services to share the same frequency band in a controlled manner. This kind of spectrum sharing should be conducted in a way that requires minimum changes to the functionalities and the architecture of the systems involved and especially to the current holders of the spectrum usage rights, thus, the incumbent spectrum users. In this paper, we concentrate on the emerging Licensed Shared Access (LSA) concept which is currently receiving a lot of attention in European regulation and standardization. We discuss different types of incumbents and the critical factors for allowing spectrum sharing with LSA from their perspective. Finally, we propose an architecture for LSA that takes into account these critical factors while guaranteeing certain quality of service (QoS) conditions for all involved systems.

Licensed Spectrum Sharing Schemes for Mobile Operators: A Survey and Outlook

“…LSA is an extension of ASA concept, which is proposed by the Conference of European Postal & Telecommunications , Electronic Communications Committee (CEPT ECC) [48], in order to facilitate use of favourable licensed bands for mobile communications use in a fully harmonised manner (noninterfering basis and guaranteed access ) and under a licensing regime with the purpose of improving spectrum usage efficiency with lower spectrum license fee compared to the case of exclusive access. However, the deployment of such new access methods may impose additional costs for sharing players.…”

“…Firstly, the concept was proposed by QUALCOMM [139], and developed further by CEPT, taking into account more comprehensive regulatory aspects (i.e., the level of authorisation), in order to form a more robust sharing regime, known as LSA. In LSA framework, a non-mobile wireless service provider, which could be a governmental/commercial [15], [85], [133] => Game-theory based approach => Cooperative games performs based on presharing agreements among MNOs + No need for real-time inter-MNO information sharing -Efficient and fair policies are complex to implement [87], [88], [97] incumbent, agrees to share part of its exclusive band with one or multiple MNOs, referred to as LSA licensees [48]. The framework was introduced with the aim of offering promising opportunities for the capacity and bandwidth expansion in cellular systems [137].…”

“…On the other hand, from the incumbent's point of view, the cost of setup and management of a database, as well as the interfaces, such as backhaul connectivity, should be taken into account. Since the required architecture in LSA is still an open topic [48], the tasks of different management units may also be divided in a different manner. Currently, it has not been specified whether the LSA is going to be deployed on a voluntary basis, or if incumbents will be obliged to deploy it by the respective NRA.…”

“…Currently, it has not been specified whether the LSA is going to be deployed on a voluntary basis, or if incumbents will be obliged to deploy it by the respective NRA. A number of business models have nonetheless been proposed and discussed in technological, regulatory and business aspects [48], [50], [101], [138], [142]. In general, an appropriate business model is required in order to determine the costs and also specify the available technological solutions that can be used to get the best possible revenue out of LSA.…”

“…The potential synergies among different incumbents and MNOs, and identify which bands are the most appropriate to use. Moreover, whole LSA sharing procedure has to be [48]. There must be a guarantee that a sharing request only occurs in the case of spectrum shortage and does not lead to permanent utilisation of the shared spectrum.…”