Contains the full lesson along with a supporting toolkit, including teachers’ notes.
How do the devices communicate?
In order to communicate, IoT devices have to connect with each other. This is accomplished over some form of network. Up to now a remote device would usually send its data to a data centre for processing. This data centre would be located somewhere in the internet or, as we now refer to it, the cloud. In an IoT scenario the data is often stored and analysed locally, in other words, at the ‘edge’ of the cloud. This is extremely useful in situations that need a rapid local response. For example, if an ambulance is taking a seriously injured accident victim to hospital across a busy town or city, a camera could detect the flashing light on the ambulance and then send messages to the traffic lights in order to ensure that the ambulance has a clear route to its destination.
This mode of communicating, storing and processing the data at the edge of the cloud is called fog computing, fog networking or just fogging. As well as being effective, it is also very efficient because it means that a lot of data does not have to be routed through longer internet links where it might be delayed. Delay in a telecommunications link is known as latency and it is easy to imagine how critical a delay could be in the ambulance example above. In order to achieve the required rapid communication, the IoT devices are often interconnected in a mesh network.