未來的網路將會是異質網路 (Heterogeneous Networks) 整合應用的時代，各類型接取網路 (Access Networks) 之網路特性不盡相同，如頻寬大小等，造成在不同接取網路中，使用者所享有的服務品質 (Quality of Service，簡稱QoS) 也有所差異，因此整合異質網路，能夠讓使用者在任何時間任何地點皆可得到適當的服務。近年來網路上群體通訊的應用程式大幅成長，如視訊會議之類的多媒體服務具很大的頻寬需求，群播服務 (multicast) 一對多與多對多的特性能夠減低網路頻寬的負載。 群播服務可降減少群體通訊應用程式對網路造成的負載，多媒體服務的即時性 (real-time) 則需要一個服務品質保證的機制來完成。面對未來異質網路，IETF所提差異性服務 (Differentiated Service, DiffServ) 剛好可以達到異質網路的延展性 (scalability)，同時保證使用者能享有服務品質。本論文提出具服務品質之IPv6群播之網路遴選系統 (System for Selecting Access Network with QoS-Aware IPv6 Multicasting，簡稱 SSANQIM)，利用異質DiffServ Domain的概念，不同網路間，系統藉由頻寬代理人 (Bandwidth Broker，簡稱 BB) 來溝通每個網路現有頻寬使用狀況，根據此資訊本論文提出四大類的網路遴選策略，幫助使用者在使用群體通訊服務時，能夠選擇最適合的網路，並同時享有服務品質。 經過實驗結果可發現，SSANQIM系統的QoS架構能確實提供群播服務具有服務品質，而四大類網路遴選策略可以考量使用者需求，幫助使用者篩選出具有服務品質的接取網路來取得群播服務。 The future of the internet will be in heterogeneous networks, in its implementation and application. The different network characteristics of access networks i.e. the size of the bandwidth is a factor that the quality of service (QoS) is dependent on, and will affect it in different types of access networks, hence the application of heterogeneous networks will enable users to be able to receive a guaranteed QoS at anytime and any place. In recent years the growth of internet based communicative applications have grown exponentially, applications such as NetMeeting have a high demand in bandwidth quality, the implementation of multicast and its characteristics of being able to send 1 to multiple sources and many to many is a excellent tool to increase the quality of the NetMeeting experience and increasing bandwidth efficiency. With multicast increasing bandwidth efficiency by decreasing bandwidth demand of net communicative applications, the real time characteristics of internet multimedia will require a system to guarantee its minimum quality service. In respect to future heterogeneous networks, the differentiated service (DiffServ) provided by IETF is just the service that will provide heterogeneous networks with scalability and at the same time provide a suitable quality of service. My thesis suggests the implementation of System for selecting access networks with QoS-Aware IPv6 multicasting (SSANQIM for short) which will increase the quality of service. This system uses the concept of the DiffServ Domain, which from different networks the bandwidth broker (BB for short) will communicate and determine the current bandwidth usage of the different networks, and based on this data 4 different types of SSANQIM will be suggested, which will help the user determine which network will be the most suitable for use, and can also guarantee the quality of service. According the results of experiments，the QoS framework of SSANQIM can provide multicast with QoS support, and four proposed network selection policies can help users who want to get multicast service to select suitable networks with QoS support.
