A Peer-to-Peer file sharing mechanism over bluetooth scatternet

• Main Authors: Yi-Min Lo, 羅義民
• Other Authors: Kuen-Liang Sue
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/72766341845711598248

碩士 === 國立中央大學 === 資訊管理研究所 === 97 === In traditional wireless networks, a mobile device must search the nearest hot spot to access the internet. A mobile device can exchange data with other devices after connecting with the base station. However, due to the limited coverage of hot spot, it’s difficult for the mobile devices to connect to the wireless network anytime in need. MANET is a mechanism to deal with these issues. The most important feature of MANET is that it does not require any infrastructure. Two near mobile devices can communicate with each other through the connection between them. Thanks to the characteristics of low cost, low power and small volume, Bluetooth is a suitable wireless technology to construct MANET. The objective of this study is to propose an efficient P2P file sharing mechanism on Bluetooth scatternet. To shorten the file seek time and reduce opportunity of broadcasting query to the whole network, some devices should be responsible for maintain file list. The list records information about sharing files in other devices. With this concept, this study takes advantages of the possible bandwidth idle during the periodic polling between Master and Slave. Each Master would maintain file list about all sharing files in internal piconet and all neighbor piconets. Besides, this study also deals with these issues: (1) How to issue and forward the request packet to data owner? (2) How to return data packets? (3) How to handle the exception if response time is up? Additionally, in the current Bluetooth standards, unnecessary piconets may be constructed. The temporary or permanent disconnection may occur when nodes move frequently. These problems may result in delay or failure of the requested data transmission. To deal with these issues, the mechanisms of resume transmission, topology optimization and packet bypass are also proposed in this study. According to the simulation result, the improved operation models can lead higher success rate.