| Summary: | 碩士 === 國防管理學院 === 國防資訊研究所 === 94 === UMTS, developed by European, is one famous of 3G telecommunication system. According to 3GPP definitions, 3G applications can be divided into 4 categories: conversational, streaming, interactive, and background. Since each category application has its QoS requirements, a differentiated service scheme is one possible solution to improve transmission performance among UMTS network applications. Usually, a differentiated service scheme can base on operations of a queueing scheme within a gateway.
This study tries to propose a differentiated service queueing mchanism with source-based flow control scheme to support packet transmission differentiated services among UMTS applications when UMTS enters all-IP stage and all UMTS traffic can be packetized. The proposed queueing mechanism can be divided into 3 modules, packet enqueue scheme, packet dequeue scheme, and flow admission indicator; moreover, according to the setting of a flow admission indicator, source-based flow control scheme is used to handle packets transmission from network application flows.
This study bases on the ns2 simulator to implement the required simulation environment. Moreover, several scenarios are executed to obverse the performance of the proposed. After examining simulation results, they show that the proposed queueing scheme can properly control packets transmission from UMTS application flows and reduce the dropped packet number transmitted from all UMTS applications. Moreover, from the packet transmission performance view, the simulation results also shows all UMTS applications receive differentiated services according to their QoS requirements.
|
|---|
