Vertical Handoffs in Wireless Heterogeneous Network

Handovers occur due to the movement of the mobile user from one area to another area. If we don‟t use handovers then whenever a user leaves the area of a particular cell then its ongoing call is immediately disconnected. The process of handovers requires a number of parameters e.g. what is the handover scheme we are using, how many channels are free. In the handover process we should also keep the QoS up to the standard. Vertical handover may be referred to as a process of transferring call connected to a network/data session from one channel connected in a cell to the core network of another. Vertical handover refers to automatic switching of the communication/ data session from one technology to the other. So, it‟s different from a horizontal handover among various wireless access points using the same technology. In future, people will have even more flexibility when true wireless internet and real-time multimedia are provided seamlessly over heterogeneous wireless networks. Optimally combining the capacity and services of the current and emerging networks requires a holistic view of mobility, resource and service management. A framework for the analysis of vertical handoff algorithm sensitivity to various mobility parameters including velocity, handoff delay and dwell time is introduced.