Dynamic Update Mechanism in Wireless Sensor Networks

Abstract

Many researches use diff environmental conditions or application requirements in WSN. In the default Deluge mechanism, it will recover a sensor node from an updating error by reloading the stored full image again or waiting for the host machine to retransmit the full image again. This strategy is easy to implement and intuitive, but replacing the current executing image by retransmitting a full image file again is resource-consuming. To avoid retransmitting the full image when performing recovery, at the time when diff-based updating procedures have been finished, sensor nodes using our recovery mechanisms will backup the received patch files (i.e. diff script) in flash memory. Our mechanisms would effectively utilize flash memory space to store several backup patch files. When recovery is needed, our mechanismswould incrementally recover a failed node by patching up the system with each of the backup patch files. In the design of our recovery mechanisms, the failed sensor node will first try its best to recover itself without the assistance of the host machine, in order to avoid affecting the operations of other normal nodes when performing recovery procedures. Thus, compared with the full image replacement strategy, our mechanisms can save many computing resources.