Abstract
LTE fourth generation networks become one of the most important trends in the modernization of telecommunications systems. According to international standards, LTE networks specify nine types of services, that differ in terms of the bit-rate (guaranteed or non-guaranteed) and priority level. Depending on the bit rate overall traffic generated during the service providing is divided into three types: unicast streaming, streaming multicast, and elastic. The priority level can be realized with use of different mechanisms - bit rate degradation, service interruption, reservation, threshold and probabilistic management - that form the foundations of the radio admission control schemes. In the paper, a model of RAC scheme is proposed with service interruption of unicast traffic and two service disciplines for multicast traffic. The recursive algorithm is proposed for calculating main performance measures of model - blocking and pre-emption probabilities for unicast traffic.