In this paper we consider call admission control in cellular environment for data sessions and voice calls of high priority. A cell is divided into two zones with different average signal to noise ratio, and each zone uses its own modulation and coding. A dynamic resource allocation scheme is further considered, which allows communication systems to utilize their resources more efficiently. All the idle channels, which are left after the voice calls, are allocated to elastic data sessions to increase their transmission rate. When a voice call arrives, required channels can be released to serve it if only elastic data calls have a minimum required bandwidth to continue their sessions. To evaluate the role of elastic traffic, analytical models with elastic and fixed data sessions are formulated and solved. For both cases we derive blocking probabilities as well as other performance metrics of interest. According to numerical results, elastic data sessions achieve higher channel utilization and their mean transmission time is ten times less than that of fixed data sessions. As a result, the mean number of elastic data sessions in the system is twice less than that of fixed data sessions. © 2011 IEEE.