摘要
The state of art pertaining to vertical handover decisions in next-generation wireless networks provides a detailed overview of vertical handover studies.This paper classifies the research initiatives under the vertical handover decision mechanism for heterogeneous wireless networks.A fair comparison of traditional and recent techniques is drafted to obtain direction of the vertical handover decision.Several issues related to seamless support on mobility management techniques have been described in the literature.The next-generation wireless network promises to offer enhanced data services compared to other networks in mobile communication.Since all next generation network(NGN)is an IP-based network,challenges drive toward providing quality of service in the handover process.The necessity of handover process is a seamless connection.The handover operations that minimize or even target the elimination of delay in new network connection establishment are most welcomed.However,frequent disconnection and inefficient seamless handovers result in handover operation failures.Most of the existing methods on handover decisions are based on mobile-controlled handovers.Here,the decisions are in-corporate in the mobile devices.Several mobile-controlled handovers take a single parameter or two or more additional parameters as a combination to evaluate the policy decision.These approaches are carefully studied and classified.
