  "Handover" is one of the techniques used to achieve the service continuity in
Fourth generation wireless networks (FGWNs). Seamless continuity is the main
goal in fourth generation Wireless networks (FGWNs), when a mobile terminal
(MT) is in overlapping area for service continuity Handover mechanism are
mainly used While moving in the heterogeneous wireless networks continual
connection is the main challenge. Vertical handover is used as a technique to
minimize the processing delay in heterogeneous wireless networks this paper,
Vertical handover decision schemes are compared and Technique of order
preference by similarity to ideal solution (TOPSIS) in a distributed manner.
TOPSIS is used to choose the best network from the available Visitor networks
(VTs) for the continuous connection by the mobile terminal. In our work we
mainly concentrated to the handover decision Phase and to reduce the processing
delay in the period of handover
