Inter-Tier Handover in Macrocell/Relay/Femtocell Heterogeneous Networks

Handover decision is one of the technical challenges in the heterogeneous network (HetNet). Current researches on this topic concentrate mainly on the two-tier networks. In this paper, we investigates the handover decision scheme for a more complex network: three-tier macrocell/relay/femtocell network. The unique characteristics of the inter-tier handover in three-tier networks are analyzed in this paper and an effective handover algorithm is proposed to reduce the frequent and unnecessary handovers based on the ideas of dwell probability and handover priority. Simulation results show that the proposed algorithm significantly reduces the number of handovers while maintaining the call dropping rate at the same level.