Research On Congestion Control Strategy Based On Quality Of Message In DTN

The TCP/IP protocol is the current use of the Internet protocol suite, which makes it possible to communicate between a large numbers of heterogeneous networks. Communication needs to ensure a relatively long-lasting end-to-end path. With the rapid development of communication technology, new network (e.g. Planetary Network, Vehicular Network and Mobile Sensor Network, etc.) in some special environment become one of the goals in research of the network technology.Kevin Fall and other scientists proposed an emerging network, called DTN (Delay/Disruption Tolerant Network) at the conference of2003SIGCOMM. With store-carry-forward method, packets forwarded between the DTN nodes under the intermittent connectivity and eventually arrived at the destination node.Due to the changing topology and intermittent connectivity, DTN usually uses multi-copy routing strategy to increase the reliability of packet delivery. However, multi-copy mechanism brings a large number of redundant packets and causes excessive consumption of network resources. The packets which are generated by multi-copy mechanism easily lead to the congestion of the node because of the limited storage space of the node. Therefore, it is important to introduce a reasonable congestion control strategy in multi-copy routing mechanism when the node storage congestion.In this paper, the concept, architecture and previous research were first analyzed and summarized, and then the epidemic routing protocol and multi-regional networks were introduced. Based on the epidemic routing protocol and multi-regional networks, the following methods were proposed:1. Congestion control strategy based on epidemic routing protocol. Under the epidemic routing protocol, the redundant packets which stored in the buffer of the node easily lead to the congestion of the network. By calculating the quality of the packets in the buffer, it can find the message which has the minimum quality and drop it to ease the congestion and improve the network performance in congestion environment.2. In this paper, the congestion of the multi-regional networks was analyzed and the congestion control strategy was proposed based on the principle of no dropping packets. In order to make better use of buffer resource and alleviate the pressure on the buffer of the core nodes, this strategy uses distributed storage mechanism to store the packets in the non-core code.3. The performance of congestion control strategy based on the epidemic routing protocol and some other routing protocols were evaluated by the ONE simulator. Then the simulation results were analyzed.