Technology To Achieve Vertical Handoff Based On Fuzzy Logic In Heterogeneous Wireless Networks

Nowadays, numerous cities are developing wireless network communication and expect tofulfill the dream of network communication that people could communicate with anyone at anytimeanywhere in any form. One of key technologies to achieve the above objective is the integration ofwireless heterogeneous networks. Wireless communications networks today is a combination ofthese different wireless networks.It is also called heterogeneous wireless networks.When mobileusers are roaming among these heterogeneous wireless networks,vertical handoff occurs.First, this paper introduces the development of heterogeneous networks and the currentresearch status. Then the characters of the future heterogeneous wireless networks is simplydescribed. The second chapter it focuses on the multi-attribute decision algorithm in heterogeneouswireless networks are common such as Simple Additive Weighting,Analytic HierarchyProcess,Grey Relational Analysis, and these types of algorithms are briefly analyzed.This papermainly studies the network selection and vertical handoff problems in heterogeneous wirelessconverged network.This paper summarizes the problem of the network selection in heterogeneous wirelessconverged network as a multi-attribute decision making problems. In this paper, the fuzzy theoryattribute is used to avoid uncertain factors, a variety of network parameters is considered toestablish multi-attribute decision model after classifying the business type, the FVHDA is used tocalculate the attributes membership vector, utility function is constructed to perform networkselection. Finally, the simulation results show that this strategy can make better use of networkresources, reduce unnecessary handoffs and provide users more reasonable choice for networkaccess.Finally, this paper studied a vertical handoff decision algorithm based on fuzzy control.Thealgorithm takes into consideration the factors of Received Signal Strength (RSS), Bandwidth,Network Delay, Service Cost and User Preference, the algorithm uses the fuzzy control method toevaluate the performance of the available networks and makes a final handoff decision according tothe service type of an ongoing session. A pre-decision method is employed in the proposedalgorithm to make an early decision for a user with high mobility or very low RSS. Simulationresults show that the algorithm can make accurate handoff decisions eliminate the ping-pong effect.