當使用在使用應用服務時，服務品質是一個很大的議題，也是使用者最在乎的，然而隨著無線接取網路的演進，使用者將可以接觸到多樣化的網路環境，因此就有可能會跨越不同型態的網路，而要如何確保使用者在無線網路上執行換手動作時的服務品質是值得去考量的。現今新世代無線網路的多媒體服務研究發展，大多是架構在IP多媒體子系統(IMS)平台上，IMS可以提供具有保障QoS的多媒體服務，故一旦進行換手就要重新建立新的End-to-End QoS，才可以繼續先前的服務，因而等待過久的時間，對於IMS大多都是及時的服務影響很大，因此本論文提出一個如何利用802.21 MIH在跨網域進行換手機制同時結合IMS換手的訊息，建立一套跨網域且跨層的換手機制，以減少使用者在跨網域使用IMS服務時所遇到換手時間延遲，進一步的讓使用者可以感受到跨網域使用多媒體服務的便利性。 QoS of application services is a critical issue when the user is use application service ,But as the wireless network is gradual progress the user can use diversified wireless network ,then it is need to consider that how to guarantee Qos when user handover in different wireless network.Now the multimedia service of the wireless network is studied base on IP multimedia subsystem (IMS), IMS can provide the multimedia service with guarantee QoS then it is big issue when user handover in different wireless network, It needs to delay the authentication and authorization of IMS and keeps resource reservation with QoS, They can just continue the previous service. Therefore they has waited for long time, So we propose an adaptive end-to-end QoS procedure utilizes 802.21 MIH to assisting network handover and combine the information that IMS changes hands at the same time, in order to reduce it is postponed for hand time that the user meets while stepping the different network and using IMS service the further one enables users to experience that step the convenience of using the multimedia service of different network handover.
