Date Added: Aug 2012
A seamless vertical handover between heterogeneous networks without interruption to the on-going services is very important in next generation wireless networks which aim at the provision of uninterrupted network connections anywhere and at any time. This paper provides a review on the vertical handover mechanism focusing mainly on the services provided by the IEEE 802.21 Media Independent Handover Standard. The Handover Execution stage is dependent on the media-specific technology. This paper also provides a brief discussion to the various approaches used to carry out the handover process depending on the parameters involved in the particular technologies and the handover decision algorithms.