Network coding and compression in wireless networks

• Main Authors: Shi, Wei-Lun, 石維倫
• Other Authors: Chen, Jyh-Cheng
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/32735899268751026634

碩士 === 國立交通大學 === 資訊科學與工程研究所 === 101 === In the past two decades, communications technologies have been improved. The densiry of wireless Local Area Networks (LANs) becomes higher and higher. Now we can detect Wi-Fi signals in many places, including restaurants, train stations, libraries, especially in densely populated areas. We can even detect several signals from different wireless base stations in the same space. As wireless LANs and mobile devices become much popular, more and more data are transferred through wireless LANs. In many cases, network coding can reduce the amount of data transmitted, and improve channel utilization. Many wireless systems have leveraged the nature of broadcast to improve wireless capacity and performance. While conventional approaches have focused on overhearing entire packets, recent designs have argued that focusing on overheard content may be more effective. For this reason, we utilize the probability of packet repeats to build a Huffman tree. We then use Huffman codes to encode packets. In order to demonstrate the feasibility and practicality of the proposed method, we analyze actual packets collected from different public areas. We also implement the Huffman coding algorithm in Linux kernel and setup a wireless router to encode transmitted packets in Linux system. Finally, we prove the practicality of Huffman encoding by Linux implementation.