Simulation and Software Implementation of ATM/AAL2 Protocol for Digital Voice Communication

• Main Authors: Jimmy Cha, 曹志銘
• Other Authors: Chang, Ching-Lung
• Format: Others
• Language: zh-TW
• Published: 2002
• Online Access: http://ndltd.ncl.edu.tw/handle/24228351193690970012

碩士 === 國立雲林科技大學 === 電子與資訊工程研究所碩士班 === 90 === Asynchronous Transfer Mode/Adaptation Layer 2 (ATM/AAL2) protocol has been greatly modified by the International Telecommunication Union-Telecommunication (ITU-T) for supporting low bit rate and delay sensitive applications. The idea of AAL2 protocol is to multiplex voice packets from different users into one ATM cell to reduce the packetization delay. Therefore, the time to fill a cell can be reduced significantly. In the other hand, the ADSL (Asymmetric Digital Subscriber Line) technologies are a new platform for bringing the broadband services to the homes and to the small businesses. In this thesis, we evaluate the performance of ATM/AAL2 for voice transport in ADSL network using simulation approach. The goal is to understand the relationship between the parameters, such as Timer-CU, voice compression rate, and CPS-SDU fill delay, and the network utilization. From the simulation results we derive the design guideline which can provide the digital voice service provider as a reference for the key parameters setting. In addition, we also implement the software based AAL2/ATM/Ethernet platform on the personal computer. Based on the software AAL2 platform, we integrate the PCI voice card to realize the voice over AAL2/ATM/Ethernet test bed which can be used to verify the voice over AAL2 behaviors.