Research On Improved Epidemic Routing And The Related Congestion Control Mechanism In DTN

DTN(Delay/Disruption Tolerant Network)is derived from the description of interplanetary communication networks,and now refers to the wireless networks which have no end-to-end path from source address to destination address at most of the time.DTN is different from the traditional networks based on TCP/IP protocol,it is characterized by intermittent connectivity,frequent node movement,asymmetric data rate,long delay and low delivery rate,etc.In order to overcome these shortcomings,it is necessary to find suitable routing protocols and design well-behaved congestion control strategies.Epidemic is one of the most classic routing protocols in DTN routing.Epidemic forwards message to every neighbor node that does not contain the message,which can flood messages into DTN fast and have the highest message delivery rate under ideal conditions.However,it consumes significant resources,which cause network congestion easily in practical applications.In order to address the above issues,this thesis proposes a enhanced Epidemic routing protocol called EPRC(Epidemic with Redundancy Clear).The proposed routing protocol can not only clear redundant messages in the DTN network effectively,but also take into account the buffer residual rate while forwarding message.The simulation results show that EPRC can forward more messages successfully at lower overhead and shorter delay.Besides,we carry out a futher research about the congestion control based EPRC routing and give a buffer management strategy based on a parameter called message redundancy.The simulation results display,the given buffer management strategy RCCS can deal with network congestion well,in other words,the message delivery rate can be increased,the overhead and average delay can be reduced at the same time.