Research On Relay Node Selection And Buffer Management Scheme In DTN

With the rapid advance of wireless communication,its application scenarios become more and more extensive.For the traditional Internet communication based on TCP/IP protocol is no longer applicable in some challenging environments where there is no complete path between the source and destination and lacking of affordable network connectivity.Kevin et al proposes a common and reliable overlay network architecture,also known as the Delay Tolerant Network(DTN).The research and development of DTN will contribute a strong theory and technical support for the message interaction on military and aviation.Meanwhile,it greatly promotes the intelligent,ubiquitous and integrated development of the future network communication.More than 95% of the messages need to be forwarded by the relay node in DTN and the resource of node is constrained.Therefore,it is significant to study the communication path selection and buffer management scheme in DTN.In this paper,the DTN system architecture and related technologies are expounded and the DTN scene is modeled.Then,the DTN relay node selection scheme and buffer management scheme are studied deeply.The main research and work are as follows:(1)A new Dynamic Energy Threshold-based DTN Relay node Selection(DETDRS)method is proposed in this paper based on the analysis of the existing DTN relay node selection algorithm and insufficient energy consideration of nodes.In DETDRS,the next hop node is ultimately determined by the reliability of the node based on the history record of information exchanges between nodes.Then the dynamic energy threshold strategy is used to value the residual energy of the node,to further determine whether to forward message.Simulation results show that the proposed scheme obtains higher message delivery rate,lower network overhead and extends the network life time.(2)For the shortcoming of estimation of the message utility,this paper proposes an advanced Multi-objective Utility based Buffer Management(MUBM)scheme.In proposed scheme,the message delivery rate and delay are modeled according to the parameters of dynamic network.Then the multi-objective utility function is used to determine the scheduling order of messages.Meanwhile,in order to solve the difficult problem of link feedback in DTN,the reserved buffer space method is adopted,and the delivered message in the network will be timely deleted.Simulation results show that the improved program has a certain improvement in the message delivery rate and delivery delay performance.(3)A joint transmission scheme of DET-MU is put forward based on dynamic energy threshold method and the improved multi-objective utility buffer management scheme.The relay node is selected in the light of the reliability in joint scheme.Then according to multi-objective utility,the sequence to schedule messages is carried out.Finally,dynamic energy threshold strategy is used to further determine whether to forward the message.Simulation results show that the joint scheme further reduces the message delay and network overhead.(4)The research work in this paper is summarized and the future research directions are prospected.