A Two-Stage Bootloader to Support Multi-application Deployment and Switching in Wireless Sensor Networks

Wireless sensor networks are built from highly resource constrained embedded systems. Supporting multiple applications on the sensor network is a desirable goal, however, these constraints make supporting multiple concurrent applications on each node difficult. Therefore, we propose a dynamic application switching approach where only a single application is active on each sensor node at a time. In this paper we present a dynamic application switching framework that can automatically reprogram the sensor node in response to application requests. We implement our framework on the TelosB platform and evaluate its performance using a 52-node sensor network testbed. The implementation of a two-stage bootloader reduces the memory requirements to only 1KiB of program memory and 8 bytes of RAM on this platform. We evaluate the implementation using two different modes of application switching; asynchronous and synchronous. Extensive performance studies indicate that dynamic application switching using our two-stage bootloader is a useful approach to support multiple applications in wireless sensor networks.