[From the last episode: The goals of this site are 1) to bring IoTThe Internet of Things. A broad term covering many different applications where "things" are interconnected through the internet. info to non-tech folks, and 2) to provide insights into how it works.]
You might want to think of the IoT as a “system of systemsA system built out of other smaller systems. Just as you might say that a system could be built out of subsystems, you can also say that separate systems can be combined to create a larger system. They're just different ways of saying the same thing..” Your computer is a systemThis is a very generic term for any collection of components that, all together, can do something. Systems can be built from subsystems. Examples are your cell phone; your computer; the radio in your car; anything that seems like a "whole.". Your phone is a system. The networkA collection of items like computers, printers, phones, and other electronic items that are connected together by switches and routers. A network allows the connected devices to talk to each other electronically. The internet is an example of an extremely large network. Your home network, if you have one, is an example of a small local network. in your house is a system; the cellular system is, well, a system. The IoT is a system that incorporates all of those systems and many more. That’s why it can be hard to wrap your head completely around it. It’s also why there are so many technologies bound up in the IoT.
Because of this, we’re going to need to probe into many different kinds of system. But before we do that, let’s take a high-level look at what the IoT consists of, starting with the three best-known pieces.
Sensing: The IoT attempts to learn things about the world so that it can make decisions or, at least, inform you about what’s happening in your world. This is the realm of sensorsA device that can measure something about its environment. Examples are movement, light, color, moisture, pressure, and many more.. Sensors can be something very physical, like a moisture sensor that tells you when your garden needs more water. Or it can be more abstract, like a little computer “agent” that detects when some important date on your calendar is near.
Computing: Sensors are pretty basic; they detect stuff. They put out data – potentially reams of data. Something has to do something with all that data; this is a job for computers big and small. At the very least, something needs to decide which data is useful and which to ignore. Some of that computing can happen right next to the sensor in the same chipAn electronic device made on a piece of silicon. These days, it could also involve a mechanical chip, but, to the outside world, everything looks electronic. The chip is usually in some kind of package; that package might contain multiple chips. "Integrated circuit," and "IC" mean the same thing, but refer only to electronic chips, not mechanical chips.; some might happen in another box somewhere in the room or building; some might happen in another building far away; and some may happen in the CloudA generic phrase referring to large numbers of computers located somewhere far away and accessed over the internet. For the IoT, computing may be local, done in the same system or building, or in the cloud, with data shipped up to the cloud and then the result shipped back down.. This is where the dreaded “algorithmsA way of calculating something, typically as a step-by-step recipe. A familiar one to all of us is how we do long division on paper: that's an algorithm. Algorithms abound in the IoT.” reside; it’s the home of artificial intelligenceA broad term for technology that acts more human-like than a typical machine, especially when it comes to "thinking." Machine learning is one approach to AI. (AI). We’ll need to look at all of those.
Communicating: We need some way to get the data from the sensor to the various computing elements, wherever they are. And, if we’re going to take action based on the computing results, then we need some way to communicate commands. Communication is a huge component of the IoT.
These are the three categories most often discussed. But there’s one more that often gets forgotten, even though it can be critical as the “final step” of anything that happens in a particular system. In fact, we’ve already alluded to it.
ActuatingA way of controlling some device electronically. It might turn the device on or off or change a setting or property or do any other thing that the device is capable of.: An actuator is something that you can control to do something. Once you’ve taken data and munged it with algorithms, you may end up with decisions that say something needs to happen. These are the commands we saw up in the section on Communicating.
In addition to these four basic elements, there are at least two other independent notions that we really need to explore:
SecurityRefers to whether or not IoT devices or data are protected from unauthorized viewers.: Can someone snoop your sensors ? Can they snoop the data as it’s communicated? Can they snoop a hard driveA type of persistent (non-volatile) memory built from rotating platters and “read heads” that sense the data on the platters. or the live memory while algorithms are chewing on the data? Can they wander freely on the network looking for other interesting bits (that might have nothing to do with your sprinkler)? Security affects everything. It’s easy to “ignore for the moment” and come back to, but many designers have found that they should have included security from the get-go. It’s a very complex topic, but new security products are making security easier to implement for non-experts. (And most engineers are non-experts when it comes to security.)
PrivacyRefers to whether or not information gathered about your usage of IoT devices by authorized people can be made public, or shared with others, without your consent. Different from (although related to) security, which protects such data and devices from access by unauthorized people. Different from privacy, which is more concerned about use of data by authorized people.: Privacy too often ends up in the same bucket as security, but I see it as very different. Yes, if you have bad security, then you’ll also have bad privacy. But, even if you have good security, if some company from whom you bought an IoT gadget is selling your data, then it’s not a security issue, but it could be a privacy issue – if you object to them selling that data.
An example: a garden sprinkler as a system of systems
The diagram/animation below illustrates more concretely how this stuff comes together as a system of systems, using a garden sprinkler as an example.
(Click to see animated version)
Here you see the moisture sensor that sends its data onto the network, perhaps via a routerAn electronic box that helps steer data on a network. For instance, you may have one in your home connecting your phone and computer and other devices to each other and to the internet. The data itself has information about where it's being sent; the router uses that information to send it in the right direction. At a really basic level, you can think of a router and a switch as being the same thing. If you want to get more technical, a switch creates a local subnetwork, and the router connects multiple subnetworks (or multiple networks). as shown. (There are many options here; we’ll talk about that later.) That data may then be sent to a local serverA computer with a dedicated purpose. Older familiar examples are print servers (a computer that controls local printing) and file servers (a computer used for storing files centrally). More modern examples are web servers (the computers that handle your web requests when you use your browser) or application servers (computers dedicated to handling the computing needs of a specific application). Servers are often powerful, expensive machines since they have to handle a heavy load. and/or to the cloud. From the cloud, an app on your phone can let your phone act as a very-remote control of the sprinklers.
If you so direct via the phone, or if some algorithm in the cloud or local server so directs, then a command can be sent to the sprinkler to do something – turn on or off or change flow.
So we have sensing via the moisture sensor; computing to decide what to do with the data; communication sending the data up, sending the commands down, talking to the cloud, and talking to your phone; and actuating to turn the sprinkler on or off. The security aspect is about whether or not some unauthorized person can get into the middle of this process and take data or change operations or otherwise prowl the network; the privacy aspect gets to whether or not you own the data and what some serviceWe are used to purchasing products outright. "Services" is a new concept where you may or may not buy the product, but optional or mandatory services come with the product. Those services may have an ongoing cost separate from the purchase price. provider, who is authorized to see the data, can do with the data.
We’ll address all of these aspects in more detail in future posts.
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