What do car parking slots in New Brunswick, Canada, the snow pack of California’s Sierra Nevada and a prescription drugs manufactory in Cork, Ireland have in common? Dust. Not the dust that we spend time chasing around the house, but Smart Dust, from Dust Networks; tiny, self powered elements working together in networks.
The history of smart dust began in the late 1990s, well before people began talking about the Internet of Things (IoT). The Defense Advanced Research Projects Administration (DARPA) the research arm of the US Department of Defense, funded research into the idea that hordes of small objects – less then a cubic millimetre in volume – could act as sensors and communicate information about the world through a wireless mesh network. In this network all the motes of dust would act as nodes, and messages would find their way from node to node until they reached a network manager for onward transmission to the application the network is serving. Such a network can be auto-forming – there is no need for network configuration – and self-healing – if you lose one or more motes the messages will find another way through the network. This is clearly valuable for military and space applications, but it also has advantages in civil, particularly industrial, projects.
The DARPA project was directed by Kris Pister, a professor at Berkeley. Pister went on to found Dust Networks, later bought by Linear Technology, and where he is still CTO. And while we are seeing a lot of discussion about IoT, Dust Networks has developed a range of technologies and deployed them in multiple implementations for a wide range of mainly industrial applications: Smart Dust is actually working.
Motes are completely wire-free, so they are designed for a long battery life (or they can be powered by energy harvesting) and they are fabricated using an ultra-low power process technology. Communication is through the WirelessHart protocol and networking technology. This was originally Dust Network’s proprietary wireless standard, which has evolved into an IEEE standard (802.15.4) and is also called SmartMesh. It uses very short messages, for the lowest power consumption, and provides 128-bit AES-based encryption, along with other security measures. This provides greater than 99.999% data reliability, even in harsh RF environments, and a greater than ten year battery life for the motes.
With the widespread growth of Internet Protocol (IP) Dust Networks now offers a second wireless option, based on 6LoWPAN (IP version 6 over Low power Wireless Personal Area Networks) which gives each node an IP address, and is working with other companies on a standard to merge the best of the two approaches.
Most of the discussion around the IoT has concentrated on individual “Things” – smart meters, central heating controls even the classic toaster – communicating to some central application. With Smart Dust, “Things” become large industrial plants, railway systems and even acres of land. With no physical connectivity and no network configuration networks are quick to set up and robust in service, extending the IoT in a number of directions.