Abstract: In opportunistic networks (oppnets), because of low density, nodal mobility, and limited transmission range, network topology will disrupt and nodes will detach from the networks. Thus, an end-to-end path from source to destination may not exist, which is a challenge for the design of routing protocols. This issue has attracted more and more attention recently. Firstly, the concept, architecture, and characteristics of opportunistic networks were introduced. Then, the progress and the new mechanisms of routing protocols for opportunistic networks were described. The present routing protocols were also classified, introduced, and compared. Finally, the future directions were given, which aimed to benefit the future research and applications of opportunistic networks.

Key words: opportunistic networks, routing protocol, carrying, dissemination, context

摘要： 在机会网络中由于网络稀疏、节点移动和通信范围等因素的影响，有可能出现网络分裂或节点脱网，源节点和目的节点之间不一定存在完整的端到端路径，这为路由协议的设计带来巨大挑战，此问题近年来引起了研究人员越来越多的关注。首先介绍了机会网络的基本概念、体系结构和特点等；然后阐述了机会网络路由协议研究的进展,概括了机会网络路由协议中的新机制，对现有路由协议进行分类并详述它们的基本原理；通过比较对各种协议的特点进行分析阐述，最后给出未来研究的方向。

关键词: 机会网络, 路由协议, 携带, 传播, 场景