On Sensor Network Reconfiguration Problem for Downtime-Free System Migrations

Many state-of-the-art wireless sensor networks have been equipped with reprogramming modules, e.g., those for software/firmware updates. System migration tasks such as software reprogramming however will interrupt normal sensing and data reporting operations of a sensor node. Although such tasks are occasionally invoked, the long time of such tasks may disable the network from detecting critical events, posing a severe threat to many sensitive applications. In this paper, we present the first formal study on the problem of downtime-free migration. We demonstrate that the downtime can effectively be eliminated, by partitioning the sensors into subsets, and let them perform migration tasks successively with the rest still performing normal services. We then present a series of effective algorithms, and further extend our solution to a practical distributed and localized implementation, namely, the Sensor Network Reconfiguration Protocol (SNRP). The performance of these algorithms have been evaluated through extensive simulations, and the results demonstrate that our algorithms achieve good balance between the sensing quality and system migration time.