Dynamic Software Updating in Wireless Sensor Networks

• Main Authors: Wei-Cheng Wang, 王維成
• Other Authors: Sy-Yen Kuo
• Format: Others
• Language: en_US
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/60970096489664711852

碩士 === 臺灣大學 === 電機工程學研究所 === 98 === A wireless sensor network consists a number of small, cheap and autonomous devices communicating with each other for monitoring environment conditions. After the deployment, there is still a need for updating the software in the nodes due to bug fixes, requirement changes, or other maintenance reasons. Software updating in wireless sensor networks has became a challenge because of the constrained hardware resources and environment. In previous works, the node is required to reboot after software update. However, reboot is costly since the previous runtime status is lost. It needs time and bandwidth to synchronize with other nodes or rebuild routing table. The thesis presents uFlow, a programming paradigm and a prototype implementation for wireless sensor networks. uFlow allows application to update without rebooting the node therefore preserving precious runtime states. The execution overhead is around 88 clock cycles, which is slightly larger than TinOS, but fortunately the overhead only occurs when task transitions. The prototype implementation is about 420 bytes for task loop and core helper APIs and 146 bytes for helper APIs used to facilitate the dynamic update, while TinyOS-1.x costs around 400bytes.