The need for efficient resource utilization at the air interfaces in heterogeneous wireless systems has recently led to the concept of downlink and uplink decoupling (DUDe). Several studies have already reported the gains of using DUDe in static traffic conditions. In this paper we investigate performance of DUDe with stochastic session arrivals patterns in LTE environment with macro and micro base stations. Particularly, we use a queuing systems with random resource requirements and to calculate the session blocking probability and throughput of the system. Our results demonstrate that DUDe association approach allows to significantly improve the metrics of interest compared to conventional downlink-based association mechanism.