A handover scheme in clustered cellular networks

There are two types of handovers for mobile users in the clustered cellular networks: inter-cluster and intra-cluster handovers. An inter-cluster handover which occurs as a result of mobile user's migration between clusters gives rise to additional handover delay, because more complex handover mechanism should be performed by mobile network.In this paper, we analyze multi-layered cluster architecture and we study the effect of cluster size on the inter-cluster handover performance. Then we propose a new hard handover scheme for inter-cluster handover. For an inter-cluster hard handover, additional delay is required for new bearer setup and reroute calculation. When a mobile terminal (MT) call crosses a cluster boundary, the proposed scheme performs some preparatory activities before actual handover is requested. It results in fast hard handover. We also analyze its performance and show that it reduces forced termination probability.