Abstract: Most existing Delay-Tolerant Network（DTN） transmission algorithms only consider the impact of node mobility on data delivery without considering the effects of available resources of each node in terms of storage，energy and processing power.How to utilize the limited resources of nodes to achieve efficient data transmission needs to be deeply investigated.This paper proposes a Buffer Aware Transmission（BAR） mechanism for resource constrained DTNs.BAR explores both node contact probabilities and remaining buffer resources to determine whether a packet is delivered when two nodes encounter.Simulation results show BAR significantly outperforms several existing known DTN transmission algorithms，in terms of data delivery ratio，data delay，and resource consumption.

Key words: Delay-Tolerant Network（DTN）, limited resource, delivery mechanism, relay capability

摘要： 在延迟容忍网络（DTN）中，已有的数据传输研究通常只考虑了节点的移动对数据转发的影响，而没考虑节点缓存等资源的限制因素。如何有效利用有限的节点资源进行高效的数据传输是一个需要重点研究的问题。提出了一种在资源受限DTN网络中高效数据传输的策略BAR（Buffer Aware Transmission Policy for DTNs）协议，BAR利用节点的相遇概率信息来提高中继的方向性，还利用当前缓存信息来提高资源的利用效率。仿真实验比较了BAR和现有的几种主流传输策略的传输性能，结果表明BAR在投递率、传输延迟和资源消耗等方面都具有明显的优势。

关键词: 延迟容忍网络, 资源受限, 传输策略, 中继能力