Study Of Routing And Buffer Management In Delay Tolerant Mobile Sensor Networks

WSN (Wireless Sensor Network) is a special type of wireless communication networks which is able to collect data in variable environments and then feed them back to people. Normally, WSN is composed of large amount of tiny self-organizing nodes. As WSN has greatly changed human life and working, it's an important state of the art technology in the 21st century.As long as real world data sensing/gathering developed further, the traditional fixed-location sensor networks are not able to qualify some specific applications such as mobile devices and creatures. The sensors are requested to move together with these objects to get more accurate data, so the DTMSN (Delay Tolerant Mobile Sensor Network) comes into eyes.DTMSN is constructed by mobile sensor nodes. The nodes'mobility, dynamic topology, high partition rate makes it different from traditional networks. To solve these problems which cause obvious delay, the"save and forward"method is adopted by sensor nodes.This thesis analyzed the structure of DTMSN, compared it to traditional sensor networks and gave the differences between them. It also researched the new challenges to routing protocols by DTMSN. After investigating and analyzing some existing routing protocols, this dissertation proposed a new scheme which has the feature of multi-hop routing and redundant messages. This scheme also combines corresponding buffer-management tactics which solved the buffer filling crisis caused by redundant messages. When the topology of the network changes quickly, connections become unstable and buffer size of the nodes are constrained, the scheme proposed by this thesis has an obvious advantage to traditional methods. It increases the success transfer rate of the messages, decreases the average transfer delay. In the same time, it supports classified Quality of Service for different-importance messages.