The Internet of Things (IoT) world, or rather some of the software giants who want to play there, seem suddenly to have recognised the likely importance of the IoT device operating system - the OS. The usual suspects are lining up to stake their OS claims, although they must all have been working on this for at least some months.

Hats into the ring from Samsung, Microsoft, Huawei and, allegedly, Google.

So what is an IoT operating system?

OK. So you’ve got your remote sensor unit. You’ve got your extremely low-powered radio module and you’ve got your battery.  So now what? You need some sort of resident firmware that hosts some sort of app (however tiny) that decides what the whole system should do, when, and with whom. That’s where your OS comes in.

Many IoT modules as currently envisaged must act in an autonomous manner. To preserve power they may spend most of their time in deep slumber, and that means that something on-board needs to wake them up at the right moment to return some data. Once communicating some sort of OS will probably be needed if there are to be any updates to the overall system; the IoT device may need to ‘hunt’ for available radio networks, there may be a requirement to change service providers and access networks several times through the long life-cycle of the device (up to 10 years is thought to be a reasonable time-frame at present) and - given this dynamic - it may even start to make sense that the radio should eventually be ‘soft’ so that it can be updated with completely new radio technology when necessary.

Obviously, how sophisticated the OS must be will probably vary widely depending on different circumstances, including: what the application is, how much power is available, what sort of connectivity can be utilised and more.

It’s in the nature of an operating system to grow in size and scope as time goes on and new refinements and tasks are thought of, so like every OS yet devised the IoT OS will need to expand.

Not surprising, then, that the flurry of OS announcements are quite diverse.

The very latest entry is from Huawei which is preparing to launch an OS weighing in at just 10 kilobytes (yes, first sighting of the ‘k’ word for at least 20 years), appropriately called ‘LiteOS’  for the internet of things, it is aimed at everything from wearables to cars. Huawei says it will be "opened to all developers" to allow them to quickly create their own smart products and it supports "zero configuration, auto-discovery, and auto-networking."

Microsoft appears to be going in at least seven directions (or editions) at once with Windows 10, due for launch this summer, and one of the editions is called ‘Windows 10 IoT Core’. This is designed for your smaller connected device. The serious (more M2M-style) devices such as ATMs, will be powered by  Windows 10 Enterprise and Windows 10 Mobile Enterprise, Microsoft says.

Samsung recently launched Artik, its small system-on-chips designed to power everything from wearable devices to home appliances. But top of this range is the Artik 10, which is a small computer and has an operating system built into it.

And finally Google, which hasn’t announced anything yet but is widely expected to do so at its upcoming I/O developers conference. Its OS - reportedly called Brillo -  will run on low-powered devices, communicate with other connected devices nearby, and is said to be designed to run in 32-64Mbytes of RAM.