A service-adaptive multi-criteria vertical handoff algorithm in heterogeneous wireless networks

The next generation wireless network (NGWN) is envisioned as convergence of heterogeneous wireless networks. The vertical handoff plays an important role in supporting the service continuity and guaranteeing the quality of service (QoS). How to select the target network becomes the vital issue of designing the vertical handoff algorithm. In this paper, we propose a novel service-adaptive multi-criteria vertical handoff (SMVHO) algorithm. The algorithm formulates the network selection process as a multiple attributes decision making (MADM) problem. The candidate networks are evaluated by a set of decision metrics including SINR, bandwidth utilization, transmission delay, packet loss rate and monetary cost. The QoS requirements and network conditions determine the comprehensive performance ranking of alternative networks. Under different network conditions, the SMVHO algorithm can keep the mobile terminal connected to the optimal network by changing the weight of each metric. System-level simulations reveal that the SMVHO algorithm is effective in lowering the dropping probability and improving overall system throughput comparing with the RSS based vertical handoff (RVHO) algorithm.