Local mobility anchoring for seamless handover in coordinated small cells

Small cells are redefining the traditional cellular system concepts. Coordination among small cells offers several benefits in terms of utilizing existing network infrastructure to support advanced interference management, mobility management as well as self-organizing (SON) functions. In this work, the problem of handover management is studied. The coordination between small cells is generally not considered in many existing handover management solutions resulting in increased handover cost, session interruption time and core network overload. To this end, a novel local anchor-based architecture for coordinated small cells is proposed in this paper based on which three handover schemes are presented. A mathematical framework is developed to analyze the performance of the proposed schemes and Markov models are utilized to obtain closed-form expressions for key handover parameters including handover cost and session interruption time. Numerical results show savings of about 60% in the signaling cost, about 50% in the data forwarding cost and more importantly about 80% in the handover interruption time compared to existing schemes based on coordinated small cells.