A Multi-Dimensional Congestion Control Mechanism in Delay Tolerant Networks
Guangsong Zhao And Ming Chen
Delay tolerant networking provides an effective communication mechanism for sparse mobile ad hoc networks by exploiting the store-carry-forward routing paradigm. Given the limited resources of DTN nodes, a large number of message copies created by replication-based routing algorithms can overwhelm node resources and result in severe congestion, which decreases the delivery rate significantly. In order to effectively mitigate congestion, a multi-dimensional congestion control mechanism is proposed in this paper, which concerns about three different perspectives (i.e., the global network, the regional network and a single node) to regulate the initial copy limit when each new message is created, control the copy division during the process of forwarding each message and instruct each node to select messages for its limited buffer respectively. Moreover, the congestion control mechanism can be widely incorporated in various replication-based routing algorithms. Extensive simulations based on ONE simulator and MIT trace dataset are conducted to verify the multi-dimensional congestion control mechanism. Simulation results show that our congestion control mechanism can effectively mitigate network congestion, and significantly improve the delivery rate.
Keywords: Delay tolerant network, replication-based routing algorithms, the delivery rate, congestion control.