Making Sensor Node Virtual Machines Work for Real-World Applications

A large number of virtual machines (VMs) have been developed for sensor nodes. Many are based on Java, although implementations based on Python and .Net also exist. Some aspects of the java virtual machine, such as the simple yet sufficiently expressive instruction set, work well on a sensor node. However, Java was developed for more powerful devices, which results in certain functionality not being ideal for resource constrained devices. While writing VM implementations and programmes to run on sensor node devices over the past decade, we encountered a number of situations where this mismatch between standard languages and the specifics of sensor node programming limited the practical use of current VMs. In this letter, we describe what we consider to be the most pressing issues and discuss how these may be resolved in future VMs.