Abstract: The movement of nodes in community-based opportunistic network has some kinds of relativity and different nodes always don’t have the same moving characteristic．However,the prevalent multi-copy message routing algorithms in opportunistic network don’t consider these characteristics adequately,which leads to high resource consumption and low transmission successful rate when deploying them directly in the community-based opportunistic network．To handle the above problems,this paper proposed a community-based power-efficient message routing algorithm．The algorithm can control the number of message copies adaptively, calculate the activity degree of target community and local community of nodes according to the meeting history of nodes with both the nodes in target community or in local community,and complete the message transmission relying on the nodes which have higher activity degrees．Simulation results show that the message forwarding times,which are the main part of energy consumption,and message transmission successful rate of the algorithm excel the spray and focus algorithm in evidence in the community-based opportunistic network which has loose requirement in delay.

Key words: Opportunistic network,Community,Routing algorithm,Multi-copy,Activity degree