Vertical Handoff Between WWAN And WLAN Decision Method And Its Optimization Mechanism

With the continuous development of mobile communication technology various wireless access technologies emerging,but do not have a single network technology can meet anytime, anywhere using a variety of today’s customers demand service in this context, the mobile switching technology to be shipped and Health. Mobile IPv6technology, and vertical and horizontal switch toggles between the two switches it can be mixed network environment to achieve seamless handover.Based on WWAN and WLAN technology and mobile IPv6technology, based on the two issues were discussed:(1) how fast vertical handoff;(2) how to move the switch to performance optimization. Focus on the adaptive vertical handoff decision method based on the bandwidth of vertical handoff decision method and the dual-binding mechanism and vertical switching broadcast during the TCP flow control mechanism is analyzed.Adaptive vertical handoff algorithm is the presence of signal presence and time algonthm algorithm, and introduces the Prediction of mechanisms. Judgement on the switch to do a more accurate prediction, the mobile node to be the most effective vertical.handoff, reduce handoff delay and other negative factors. Downstream bandwidth switching mechamsm based on the use of WLAN in the available bandwdth to determine the factors that switch. In practice, users can ge, the best network applications. Solved in the past only the determinants of the signal strength of the shortcomings arising. In both switching decision algorithm, the decision to switch on their factors were more in-depth analysis.Optimization of mobile switching mechanism includes two parts-TCP flow control mechanisms and dual broadcast binding mechanism. Because of this paper between WWAN and WLAN vertical handoff, the mobile switching performance optanzaton mechanisms for vertical handoff area to the main discussion. Which the receiver-based TCP flow control mechanism to solve the vertical handoff process to bring the TCP packet loss rate and the corresponding wireless link buffer overflow and other unfavorable factors; double sowing binding mechanism is mainly solved quickly smooth vertical switch switching problem, to a certain extent, reduces the handover latency, reduce packet loss during mobile switching rates and other unfavorable factors.The paper studied and optimized vertical handoff decision algorithm for mechanisms to ensure the effective management of mobile nodes in the mobile switching process of the various operations performed, reducing the handoff delay and improve the handoff performance...