一种基于社区机会网络的消息传输算法

A Message Transmission Scheme for Community-Based Opportunistic Network

由人携带的具有短距离通信接口的移动设备所组成的网络具有社区性质.当前机会网络中主流的多拷贝路由算法并没有考虑到节点的社区性质,如果将这些算法直接应用到社区机会网络中会造成传输延迟大、消息丢失率高等问题.针对这些问题,提出了一种基于社区机会网络的消息传输算法(CMTS),能够根据节点之间的通信频繁程度,自动将节点划分成不同的社区,自适应地控制消息的拷贝数量并依靠活跃节点将消息传输到目标社区.仿真结果表明,在延迟要求宽松的社区机会网络中,与Sprayand Focus算法相比,CMTS算法能够在保证较高消息传输成功率的同时,减少了约20%的消息转发次数,有效地降低了网络资源的消耗.

The proliferation of mobile devices has witnessed the extensive research on opportunistic network in both academia and industry. Community-based opportunistic network combine the social people and wireless communication devices so that characteristics from both the opportunistic network and social networking are inherited. However, the prevalent multi-copy message routing algorithms in opportunistic network will lead to long transmission delay and high message loss rate when deployed directly in the community-based opportunistic network. To tackle the above problems, a community- based message transmission scheme （CMTS） is proposed in utilizing the clustering characteristics of all the nodes in community-based opportunistic network. CMTS utilizes Newman＇s weighted network analysis method to organize network nodes into different communities based on the contact frequencies among them. In dealing with intra-community communication, CMTS determines the number of message copies in the network and chooses more active nodes as the relays. For inter-community communication, messages are transmitted to target communities mainly relying on the nodes which have larger social degrees. Simulation results show that CMTS can balance well the tradeoff between delivery ratio and resource consumption in community-based opportunistic network. The evaluation results also show that CMTS can reduce the message forwarding times by about 20% when compared with Spray and Focus.