State-based pipelining for reprogramming wireless sensor networks

Reprogramming is an important service for wireless sensor network to faciliate management and maintenance tasks. It uses the pipelining method, in which code images are divided into several segments, and segments are distributed in parallel. It is an effective way to reduce completion time. As we increase the number of segment divisions, we can increase the speed of code distribution. However, control messages increase as the number of divided segments increase, and that consumes more energy. The relationship between the speed of distribution and the number of control messages is therefore a trade-off. In existing pipelining, the number of segment divisions is determined as an entire network, that but this determination disregards the status of each node. It impairs the nodes which want to reduce the number of messages for various reasons. To solve this problem, we propose the state-based pipelining that can take the state of each node into consideration. In this method, each node can determine the number of segment divisions by itself.