“…In the case of Engset sources, the intensity of arrival of new calls of particular classes decreases with the increase in the number of serviced traffic sources (the occupancy state of the system), whereas in the case of Pascal sources, the intensity of arrival of new calls of particular classes increases along with the increase in the number of serviced traffic sources (the occupancy state of the system) [25,53]. Values A En, j,c (n) and A Pa,k,c (n) of traffic offered, respectively, by Engset sources from set Z En, j and Pascal sources from set Z Pa,k , generating calls of class c in state n of busy AUs, can then be determined as follows:…”