The Research On Utility Routing Algorithm Based On Value Of Node In Delay Tolerant Network

Internet has become the world’s largest network system, whose routing strategyis based on TCP/IP protocol. Therefore, internet is based on the followingassumptions: network must have a continuous, end-to-end path, a short round tripdelay, symmetrical data transfer rates, low error rates. However, in real world, somenetworks are just contrary to the internet. They are characterized by a long delay,unstable connection, high error rates. So, the current protocols and standards forinternet do not apply to this kind of networks. Researchers define such kind ofnetworks as delay/disruption tolerant network (simply as DTN). DTN network isfrequently disconnected, so routing is the key issue in DTN network. This paper isresearch on DTN routing algorithm.In order to solve the problems that network resources allocated to messages areunbalanced and the load of node is not balanced in traditional routing algorithms indelay/disruption tolerant networks, a utility routing algorithm based on the value ofnode combined with the message utility is proposed in this paper. It is a multi-copyrouting strategy and also a utility routing policy. The algorithm is divided into threeaspects: First, it selects the highest priority message (message with the leastremaining TTL (time to live property) and the shortest distance to the destination) toforward based on message utility dynamic changing. This allows allocating relativelybalanced network resources to each message. Besides, it selects the next hop based onthe value of node, which relates to the speed and remaining buffer of the node. Thiswork balances the load of each node. What is more, it adopts some buffer managementmechanisms to free buffer.Simulation results and performance analysis show that, the performance of newalgorithm improves obviously compared to Epidemic, Spray and Wait, PropHet andORWAR. It improves1.46%,20.06%,8.7%,8.21%in average delivery ratio, reduces11.1%,20.82%,15.24%,8.33%in average latency and reduces40.09%,91.50%,77.95%,83.3%in average buffer time respectively. Besides, we do experiment withvariable buffer size, it shows that regardless of the size of the buffer, the performanceof the algorithm is stable. And it improves13.96%,19.56%,17.96%,4.56%inaverage delivery ratio, reduces10.18%,26%,5.69%,19.3%in average latency.Therefore, the algorithm proposed in this paper is applicable to the situation withlimited buffer resources.In short, this paper has designed and implemented a utility routing algorithm based on the value of node. The algorithm improves the overall performance of thenetwork by message scheduling and optimizing the utilization of network resources.