A Study of Reliable Anycast and Multicast Techniques in Mobile Ad-hoc Networks

• Main Authors: Sheng-Chang Chen, 陳聖章
• Other Authors: Chyi-Ren Dow
• Format: Others
• Language: en_US
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/80799313828120024210

博士 === 逢甲大學 === 資訊工程所 === 97 === Mobile ad-hoc network (MANET) is one of the most vibrant and active research fields today. Because nodes can move arbitrarily in MANETs, the routes of transmission from senders to receivers are not stable. Therefore, this work studies the reliability issue of anycast and multicast techniques in MANETs. Although some existing anycast and multicast schemes have been developed to enhance the reliability of packet transmission, they may cause high control overhead or low packet delivery ratio when there are many senders and receivers. For anycast technology, this work proposes an efficient anycast scheme for discovering k services in MANETs. In this scheme, an anycast tree based on the virtual backbone is established to reduce unnecessary message transmission. In the anycast tree, anycast clusterheads disseminate service information to certain specific nodes that take the service information and perform the service selection task. Furthermore, to decrease the cost of service information collection and maintenance, scope flooding is used to limit the information transmission, and information piggybacking and periodical inquiry mechanism are used to increase the service information consistency. For multicast technology, this work also presents a reliable multicast scheme for MANETs. A lost packet recovery scheme is developed for reliable packet transmission, called the Recovery Point (RP) scheme. The RP scheme maintains the data packets received from the source for recovering lost packets for its downstream RPs. In addition, we combine the FEC technology with our RP scheme to enhance the reliability of our RP scheme. A mergence scheme for RP is also proposed to avoid excessive control overhead. Experiments were conducted to evaluate the proposed anycast and multicast schemes. The results demonstrate that our scheme outperforms other schemes in terms of service satisfactory ratio, normalized overhead, packet delivery ratio, and multicast efficiency.