Valuable First Forwarding (VFF) Transmission Strategy for Epidemic Routing in Urban Environments
The message queue mode in sending buffer of mobile node can impact the performance of Delay Tolerant Network (DTN). In urban environment, mobile nodes have a certain community-based movement feature, and which is related to time of day. The queue management of Epidemic routing can be improved in this environment, because some messages of a node are difficult to be transmitted to another community group within short contact time and limited transmission bandwidth. Some packets have not got a transmission opportunity when the Time To Live (TTL) of packets are exhausted. In order to make the messages delivery as much, the queue management in sending buffer becomes an important issue in DTN. The valuable message should be forwarded first, but how to define the value of a message? Therefore, we focus on improving the performance of Epidemic routing in urban environments and Valuable First Forwarding (VFF) transmission strategy in sending buffer is proposed. The TTL and message hops are jointly considered in this strategy, and the simulation results suggest that the VFF outperforms the random, FIFO and optimized MinHop (MH) queue mode in end-to-end path latency, delivery ratio and network overhead ratio.
