Location-based content search approach in hybrid delay tolerant networks

• Main Authors: Lee, Hsin Ti, 李欣諦
• Other Authors: Tsai, Tzu Chieh
• Format: Others
• Language: en_US
• Online Access: http://ndltd.ncl.edu.tw/handle/90800009211886498280

碩士 === 國立政治大學 === 資訊科學學系 === 100 === In Delay Tolerant Networks (DTNs), the offline users can, through the encountering nodes, use the specific peer-to-peer message routing approach to deliver messages to the destination. Thus, it solves the problem that users have the demands to deliver messages while they are temporarily not able to connect to Internet. Therefore, by the characteristics of DTNs, people who are not online can still query some location based information, with the help of users using the same service in the nearby area. In this thesis, we proposed a Location-based content search approach. Based on the concept of three-tier area and hybrid node types, we presented four strategies to solve the query problem. They are Data Replication, Query Replication, Data Reply and Data synchronization strategies. Especially in message transferring, we proposed a Message Queue Selection algorithm. We set the priority concept to every message such that the most important one could be sent first. In this way, it can increase the query success ratio and reduce the query delay time. Finally, we evaluated our approach, and compared with other routing schemes. The simulation results showed that our proposed approach had better query efficiency and shorter delay.