Terra: Flexibility and Safety in Wireless Sensor Networks

摘要

Terra is a system for programming wireless sensor network (WSN) applications. It combines the use of configurable virtual machines with a reactive scripting language that can be statically analyzed to avoid unbounded execution and memory conflicts. This approach allows the flexibility of remotely uploading code on motes to be combined with a set of guarantees for the programmer. The choice of the specific set of components in a virtual machine configuration defines the abstraction level seen by the application script. We describe a specific component library built for Terra, which we designed taking into account the functionality commonly needed in WSN applications-typically for sense and control. We also discuss the programming environment resulting from the combination of a statically analyzable scripting language with this library of components. Finally, we evaluate Terra by measuring its overhead in a basic application and discussing its use and cost in a typical monitoring WSN scenario.