Roi-based Forwarding Strategy For Named Data Delay Tolerant Networking

Named Data Delay Tolerant Networking(NDDTN)is a fusion of Named Data Networking(NDN)and Delay Tolerant Networking(DTN).An efficient forwarding strategy can not only help users retrieve the desired content quickly and accurately,but also have low transmission delay and network overhead.However,the research on the forwarding strategy in wireless NDN is mainly for the network with better connectivity,which is not suitable for NDDTN.Thus,an efficient forwarding strategy is a key to NDDTN.A Preference Location-Based Routing strategy(PLBR)in DTN can be used for the data reply phase of NDDTN.PLBR computes the similarity of node and the destination node according to the cumulative visiting time of preference locations,and the forwarding strategy selects appropriate relay nodes based on the similarity.However,PLBR does not take into account the time difference of different nodes accessing the same preference location,and it considers insufficiently of the situation that around the current node,there are no nodes that have the same preference location as the destination node.In this thesis,aiming at two deficiencies of PLBR,a Region of Interest(ROI)-based Forwarding strategy(RIF)and its improvement strategy are proposed for NDDTN:compute cumulative visiting time and the number of total visits by time slice for getting the similarity of node and the destination node;introduce the geographical adjacency of ROIs,select appropriate relay nodes according to similarity and adjacency of ROI sets of nodes.This thesis implements RIF and RIF2 on ONE and uses real mobility traces to evaluate the performance of them.Simulation results indicate that compared with PLBR,RIF2 improves the delivery ratio by 7 percent,and has lower delay and overhead ratio.