中文摘要：

社会机会网络由人携带的带有短距离通信接口的移动设备利用人的移动形成，其数据采用“存储．携带一转发”的模式进行传输，本文针对这类网络，提出了一种基于中间中心度的P2P查询算法（P2PQuerybasedonBetween．nessCentralityForwarding，PQBCF）．节点的中间中心度描述了节点在信息传输转发过程中的参与度和重要度，PQBCF算法通过选择具有较大中间中心度的节点来实现信息的高效转发．仿真实验表明，与目前该研究领域的SF（SprayandFocus）等主流算法相比，PQBCV算法能够有效提高查询成功率，并降低查询延时．

英文摘要：

With the proliferation of high-end mobile devices that feature wireless interfaces,many practical applications are enabled in opportunistic networks which comprise mobile devices. Contrary to the traditional networks, opportunistic networks utilize the mobility of nodes to relay messages based on the store-carry-forward paradigm. We propose an efficient P2P query algorithm based on betweenness centrality forwarding （PQBCF） for opportunistic networking, which adopts the metric of betweenuess centrali- ty from social network analysis to estimate the active degree of nodes in the networks. PQBCF leverages nodes with greater between- ness centrality as relays to increase query success rate and reduce query latency. Simulation results demonstrate that PQBCF outper- forms most state-of-the-art algorithms and achieves approximate efficiency as epidemic with much less resource consumption.