Study of Reliable Multicast in MANET by Using Coordinators and Link Lifetime

• Main Authors: Ming-Hui Lu, 盧明輝
• Other Authors: Yen-Wen Chen
• Format: Others
• Language: zh-TW
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/03736368377636190524

碩士 === 國立中央大學 === 資訊工程研究所 === 92 === Recently, the increase of the usage of portable devices, such as laptop computers, PDA, develops the wireless network. MANET (Mobile Ad Hoc Network) has the characteristics of complete wireless, mobility and non-infrastructure. It can deploy wireless LAN under any environment. However, present routing protocols, use the minimum hop count for route selection, are not suitable in MANET. So we suggest to use the link lifetime for route selection in our study. The most characteristic operation in MANET is multicast. Multicast operations in mobile networks are generally used for dissemination of important and confidential information. Multicast algorithms are hence expected to ensure a reliable message delivery. In reliable multicast, as the number of the group members grows, the number of ACK message increases dramatically. This leads to a heavy burden on source and causes more severe congestion and data losses in network. So coordinators are always used to reduce the number of ACK message and the burden on source. In this thesis, we propose a scheme to decide coordinators for reliable multicast. Using coordinators and this reliable multicast algorithm, we can ensure the reliability under the enough buffers. We analyze the variation of the number of the coordinators, the control messages and the retransmitted data under the different motion frequencies. The required buffer size is also estimated in our simulations.