QoS-oriented channel assignment strategy for hierarchical cellular networks

In the third generation of wireless cellular communication systems, cell sizes are expected to become smaller in order to accommodate high user density and multimedia traffic. In such a system, where hierarchical cellular networks are used, microcells may coexist with macrocells. Resource allocation schemes will have to be dynamic and flexible to handle user mobility and traffic variation. In this paper, we propose a new allocation strategy to manage both fast and slow users resources request in such a network. Our contribution uses an enhanced mechanism based on preemption which can be viewed as a reversible strategy on-demand using channel re-allocation. The originality of this work is to take into account the current value of QoS criteria provided to mobile users to perform resource allocation. Our new scheme is simulated and performance is analyzed in terms of new call blocking and dropping handover probabilities and signalling load. Results show that proposed resource management policy reduces significantly call blocking and dropping probabilities compared to other proposals with lower signalling increase.