The modern development of the telecommunication technologies is closely related with the rapid data traffic growth problem under the conditions of limited frequency resources for mobile networks. One of the possible solutions to this problem is the utilization of the Licensed Shared Access (LSA) framework, which is developed with the assistance of ETSI. The LSA spectrum is shared between the owner (incumbent) and LSA licensee (e.g., mobile network operator). At any time, LSA spectrum could be used by incumbent or mobile network operator but not together at once. In this connection, if the incumbent needs its frequency, then LSA band becomes unavailable for mobile operator. This leads to service interruptions for mobile operator users. Service interruption has a significant impact both on quality of service (QoS) and quality of experience (QoE). In this regard, we propose the model of the LTE network cell with LSA framework as a finite capacity queuing system with unreliable server. The important QoS parameters of the model are moments of queue and service sojourn time. We derived formulas and provide numerical analysis of these performance measures. © ECMS Zita Zoltay Paprika, Péter Horák, Kata Váradi,Péter Tamás Zwierczyk, Ágnes Vidovics-Dancs, János Péter Rádics (Editors).