A software architecture and supporting kernel for largely synchronously operating sensor networks

The largely synchronous sensor network software architecture (LaSSeNSA) was formulated with the goal of enabling efficient construction of sensor networks that are easily analyzable and can rarely run into a chaotic situation. There are largely three parts in LaSSeNSA; (1) Global time based coordination of uses of shared communication channels; (2) Global time based coordination of group configuration updates; and (3) Global time based coordination of sensing, communication, and relay activities. The essence of LaSSeNSA as well as various issues related to optimal implementation is presented. For efficient implementation of LaSSeNSA, a sensor node operating system supporting time-triggered functions (TTFs) is highly desirable. Our first prototype of TTF support facility was built as an RT subsystem on a small-footprint time-sliced multi-threading kernel. The prototype including both the kernel and the TTF support subsystem is called the TTF Support OS (TSOS). Major features of TSOS and a sensor network application development experiment are also presented.