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Smart homes and the Internet of Things

Back in 1923, brilliant Swiss-born architect Le Corbusier (1887–1965) described a house as "a machine for living in"—and slowly, during the 20th century, that metaphor turned into reality. First, the arrival of convenient, electric power started to strip away the drudgery from all kinds of domestic chores, including washing clothes and dishes and vacuuming the floor. Then, when transistors made electronics more affordable in the mid-20th century, appliances started to control themselves in a very limited way, using built-in sensors and programmers. But it's only now, in the 21st century, that the vision of the fully automated, smart home is actually being realized. Thanks to the Internet, it's easy to set up virtually any electric appliance in your home so you can control it from a Web browser anywhere in the world. And, before much longer, all kinds of net-connected machines will be talking to one another, running much more of our lives automatically through what's known as the Internet of Things. Like the idea of living in a smart home? Or an automated future that takes care of itself? Let's take a closer look at how it might work!

Photo: Smart homes are more environmentally friendly: Internet-connected smart appliances and electric cars can use signals from the electricity grid to figure out when power is cheapest and greenest. Photo by Dennis Schroeder courtesy of US Department of Energy National Renewable Energy Laboratory (NREL), image id # 112737.

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  1. What is a smart home?
  2. How do smart homes work?
  3. But do you really need a smart home?
  4. The Internet of Things
  5. Find out more

What is a smart home?

A smart home is one in which the various electric and electronic appliances are wired up to a central computer control system so they can either be switched on and off at certain times (for example, heating can be set to come on automatically at 6:00AM on winter mornings) or if certain events happen (lights can be set to come on only when a photoelectric sensor detects that it's dark).

A plug-in Smiths time switch for controlling ordinary home appliances.

Photo: The simplest kind of home automation. Plug this time switch into your electrical outlet and it will switch any appliance on and off up to four times a day. This one is digital and uses a battery powered clock. Others have large, slowly rotating wheels with dozens of tiny switches you press in or out to switch appliances on and off as many times as you like. Inside, switches like this use a simple relay that allows a small switching current from the clock circuit to switch the much bigger power circuit on and off.

Most homes already have a certain amount of "smartness" because many appliances already contain built-in sensors or electronic controllers. Virtually all modern washing machines have programmers that make them follow a distinct series of washes, rinses, and spins depending on how you set their various dials and knobs when you first switch on. If you have a natural-gas-powered central heating system, most likely you also have a thermostat on the wall that switches it on and off according to the room temperature, or an electronic programmer that activates it at certain times of day whether or not you're in the house. Maybe you're really hi-tech and you have a robotic vacuum cleaner that constantly crawls around your floors sweeping the dust?

All these things are examples of home automation, but they're not really what we mean by a smart home. That concept takes things a step further by introducing centralized control. In the most advanced form of smart home, there's a computer that does what you normally do yourself: it constantly monitors the state of the home and switches appliances on and off accordingly. So, for example, it monitors light levels coming through the windows and automatically raises and lowers blinds or switches the lights on at dusk. Or it detects movements across the floor and responds appropriately: if it knows you're home, it switches light and music on in different rooms as you walk between them; if it knows you're out, it sounds an intruder alarm.

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How do smart homes work?

Assuming you're not (yet) in the Bill Gates league of having a multimillion dollar smart home built from the ground up, you'll probably be more interested in adding a bit of automation to your existing appliances with as little fuss as possible. Modestly smart homes like this range in complexity from basic systems that use a few plug-in modules and household electricity wiring to sophisticated wireless systems you can program over the Internet. Here are the three most common flavors:

Plug-in X-10 modules

Developed in 1975, the oldest and best-known smart home automation system is called X-10 (sometimes written "X10") and uses your ordinary household electricity wiring to switch up to 256 appliances on and off with no need for any extra cables to be fitted.

Powerhouse X10 appliance module

Photo: An X-10 module used for controlling household appliances made by Powerhouse. You can see the two dials used for setting the unit code (top) and house code (bottom). Photo by Phylevn published on Flickr in 2009 under a Creative Commons Licence.

You plug each appliance you want to automate into a small control unit (usually called a module) and plug that into an ordinary electrical power outlet. Using a small screwdriver, you then adjust two dials on each module. One dial is what's called the house code and you set this to be a letter from A through P. You can use the house code to link appliances together (for example, so all the lamps on the first floor of your home can be controlled as a group). The other dial is set so each individual appliance has a unique identifier known as its unit code, which is a number 1–16. Next, you plug a central controller unit into another electrical socket and program it to switch the various appliances on and off (identifying them through their codes) whenever you wish.

How does it work? The central controller sends regular switching signals through the ordinary household wiring, effectively treating it as a kind of computer network. Because these signals work at roughly twice the switching frequency of ordinary AC power (which works at 50–60Hz), they don't interfere with it in any way. Each signal contains a code identifying the unit it relates to (a table lamp in your living room, perhaps, or a radio in your bedroom) and an instruction such as turn on, turn off, or (for lamps) brighten, or dim. Although all the control units listen out for and receive all the signals, a particular signal affects only the appliance (or appliances) with the correct code. Apart from appliances that receive signals, you can also plug in sensors such as motion detectors, thermostats, and so on, so the system will respond automatically to changes in daylight, temperature, intruders, or whatever else you consider important. With most systems, you can also switch appliances on and off with a handheld remote control (similar to a TV remote). The remotes either send signals directly to each module using radio wave (RF) signals or communicate with the central controller, which relays the signals accordingly.

X-10 has become an international standard for controlling appliances, but it's not the only system that works this way.

Computer-controlled X-10 system

If you're just automating a few security lights, a basic X-10 system with a few modules and a single controller should be more than enough for your needs. But if you want to run a more sophisticated setup, with many different appliances coming on and off in all kinds of different ways, you might want to use your home computer as the controller instead. That's easy too! You buy an X-10 home computer interface kit comprising a module (which plugs into a power outlet like any other module), an interface cable to connect the module to your computer (using either a standard serial or USB port), and some software. Typical software shows a graphical representation of all your appliances and lets you set on/off patterns for a day, a week, or even longer. You can also create your own macros so groups of appliances switch on and off in a certain sequence at a certain time each day. There's X-10 software for both Windows and Linux systems.

A wireless broadband Netgear router

Photo: You can use a wireless router to control an X-10 system remotely over the Internet, but you'll need to set up an IP address so you can access your router and computer securely from elsewhere. Dynamic DNS and Port Forward are very useful if you're going to do this kind of thing.

Wireless Internet system

Security is one of the biggest reasons why many people are interested in smart homes. If you're away at work or on holiday, making your home seem lived in is a good way to deter intruders. A basic X-10 system can turn the lights and the TV on and off at unpredictable times, but if you really want to push the boat out on security, a wireless, Net-connected system is much better. Effectively, it's a computer-controlled X-10 system with an interface you can access over the Web. With a system like this, you can hook up webcams to watch your home (or your pets), switch appliances on and off in real time, or even reprogram the whole system. Harmony Home Automation is an example of a system that works like this.

DIY smart homes

Lots of people like simple, off-the-shelf, plug-and-play systems like X-10: buy it, take it home, plug it in, and off you go. But plenty more of us are hobbyists, hackers, and geeks for whom the very challenge of doing something is at least as important—sometimes more so—than the thing we're actually trying to do. If you're one of these people, you're route to a smart home is more likely to be through the hacker, maker, DIY community, maybe using something like an Arduino microcontroller to link your computer to appliances around your home. There are quite a few projects of this kind on websites like Instructables, and I've listed them in the "Find out more" section below.

But do you really need a smart home?

You might think the idea of a smart home is frivolous and silly. Isn't it lazy and indulgent to have a machine switching the lights on and off for you when you can do it perfectly easily yourself? Bear in mind, though, that many elderly and disabled people, and those with special needs, struggle with simple household tasks. Home automation could make all the difference between them being able to live happily and independently in their own home or having to move into expensive sheltered accommodation.

Elderly people UK road traffic sign. Crown copyright.

Artwork: Elderly people ahead. Crown copyright traffic sign from the UK Traffic Signs Images Database published under the Open Government Licence.

As the population ages, governments and medical charities are looking at home automation with increasing interest: why not use computers, robots, and other technologies to provide the support that vulnerable people need to keep them happy, healthy, and independent? For example, people with dementia can have their homes fitted with automated sensors that check whether cookers have been left on or taps have been left to overflow. Elderly people prone to falling can have their homes fitted with lighting activated by motion sensors, so that if they get up in the middle of the night they're not stumbling around dangerously in the dark. Blind people can finally buy ordinary household appliances and use one simple computer controller, programmed to suit their personal needs, to manage them all.

If you're elderly or disabled, home automation systems like this can make all the difference to your quality of life, but they bring important benefits for the rest of us as well. Most obviously, they improve home security, comfort, and convenience. More importantly, if they incorporate energy monitors, such as thermostats, or sensors that cut the lights to unoccupied rooms, they can help you reduce household energy bills; automated systems such as Bye Bye Standby, which cut the power to appliances when they're not being used, can dramatically reduce the energy wasted by appliances such as washing machines, dishwashers, and TVs when they're not actually being used.

Maybe you're still not convinced—and maybe you're right. Do you really need things like this? Do you need to buy even more appliances just to control the ones you already have? Isn't it just as easy to get into the habit of switching things off yourself? Gadgets that kill your TV's standby mode sound cool, but how hard is it to pull out the plug? What about switching the TV off altogether and reading a book? Or putting your games console away in the cupboard and getting into the habit of taking walks in the country instead? And instead of going to great lengths to wire up your house for while you're away on vacation, how about befriending the neighbors and asking them to look out for you instead? For many of us, a house really is a machine for living in—and if that's the way you like living, it's just fine. But it's important to remember that there are plenty of alternatives to living that way as well. If small is beautiful and simple is best, the smartest home might be one that has no gadgets at all!

The Internet of Things

Internet of Things concept: appliances inside a house linked together

Artwork: The Internet of Things could see many billions (or even trillions) of appliances and inanimate objects all connected together.

One of the things that makes people smart—smarter than all the other creatures who creep, flap, hoof, and slither round the planet—is our ability to communicate with one another. We can talk to other people, listen to them, and collaborate to achieve very complicated goals, from finding cures for cancer to putting astronauts on the Moon. Even before the invention of the Internet, people were intricately networked, right round the world; famously, according to sociological theory, there are only six degrees of separation (six links) necessary to connect any one person on the planet with any other.

Now what if gadgets and machines could talk to each other the same way? What if an accelerometer embedded in a cardigan could automatically detect when an old person fell down the stairs and telephone an ambulance? What if all the homes in the United States had smart power meters that could signal energy consumption to utility companies in real-time? Suppose car engines could monitor their own mechanical efficiency, and, if it fell below a certain level, dial into a garage computer and be remotely tweaked back to some optimum level, all without leaving our drives? What if highway control systems could measure and monitor cars streaming down different routes at different times of day and automatically re-route traffic round jams and snarl-ups? These things might sound fanciful, but they'd all become possible if the machines in our homes, offices, and transportation systems could communicate with one another automatically—if, in other words, there were a giant network of machines: an Internet of things.

What is the Internet of Things?

People have been getting excited about this idea since it was originally suggested in 1999 by technology entrepreneur Kevin Ashton, then working in brand marketing at Proctor & Gamble. He'd been researching electronic sensors and RFID tags (wireless printed circuits that allow objects to identify themselves automatically to computer systems; they're used in library self-checkouts) and, in a moment of insight, wondered what would happen if all kinds of everyday objects and machines could communicate through a standard computer network. Ashton realized his Internet of Things was a yellow-brick road to better efficiency and less waste for all kinds of businesses.

In popular news articles, the Internet of Things is often explained by introducing a well-known but frivolous and now rather hackneyed example. Suppose your refrigerator could use RFID tags to detect what products it contained and how old they were. If it were linked to the Internet, it could automatically reorder new supplies whenever it needed to. It sounds harmless enough, but the infamous Internet fridge has actually become something of a distraction from much more valuable applications: most of us are capable of keeping tabs on our sour milk and moldy cheese, the argument goes, so what possible use could there be for an Internet of Things? But suppose similar technology were being used to monitor elderly or disabled people so they could continue to live safely, with independence and dignity, in their own homes? It's easy to build a home that uses motion sensors to monitor when someone is regularly walking around (intruder alarms have been using this technology for years), and not much harder to monitor that data remotely. That's a much more persuasive example of how the Internet of Things could prove really helpful to a society with a rapidly aging population.

Although people sometimes talk about the Internet of Things as though it's merely an extension of smart home technology, it's actually a much bigger and more general idea. Imagine our system for monitoring the elderly transplanted to a hospital and scaled up into a kind of e-care, in which noncritical patients are routinely monitored not by nurse's observations but by remotely gathered electronic sensors, communicating their measurements over a network. Or, to take another example, what about automatically monitoring your home while you're on holiday using sensors and webcams? If it works in a house, it works anywhere: for checking and automatically restocking shelves in a supermarket, for remotely monitoring the crumbling concrete on a highway bridge, or in a hundred other places.

How does it work?

Five basic things are needed to make the Internet of Things work.

1. The thing

First, there's the "thing" itself—which could be anything from a person or animal to a robot or computer; champions of the technology have even speculated that one day the Internet of Things could extend to things as small as bits of dust. Generally speaking, the "thing" is something we want to track, measure, or monitor. It could be your own body, a pet, an elderly relative, a home, an office block, or pretty much anything else you can imagine.

2. The identifier

An RFID tag concealed in a price and size label from a pair of shoes

Photo: RFID tags, like this one concealed in a price label on a pair of shoes, allow objects to identify themselves to the Internet of Things.

If we want to be able to connect things, monitor them, or measure them, we need to be able to identify them and tell them apart. It's easy enough with people: we all have names, faces, and other unique identifiers. It's also relatively easy with products we buy from stores. Since the 1970s, most of them carried have unique numbers called Universal Product Codes (UPC), printed on their packs using black-and-white zebra patterns—barcodes, in other words. The trouble with barcodes is that someone has to scan them and they can "store" only a very small amount of information (just a few digits). A better technology, RFID, allows objects to identify themselves to a network automatically using radio waves, with little or no human intervention. It can also transmit much more information.

3. The sensors

If an object simply identifies itself to a network, that doesn't necessarily tell us very much, other than where it is at a certain time. If the object has built-in sensors, we can collect much more useful information. So automatic sensors that can routinely transmit automatic measurements are another key part of the Internet of Things. Any type of sensor could be wired up this way, from electronic thermometers and thermocouples to strain gauges and reed switches.

4. The network

It makes sense for things to exist and communicate on a network the same way that computers exist and talk to one another over the Internet—using a standard agreed communication method called the Internet Protocol (IP). IP is based on the idea that everything has a unique address (an IP address) and exchanges data in little bits called packets. If things communicate using IP, or use something like WiFi to talk to an Internet-connected router, it opens up the possibility of controlling them from a Web browser anywhere in the world. That's why we're now seeing home security and monitoring systems that allow you to do things like turning your central heating on and off with smartphone apps.

5: The data analyzer

Once we're collecting masses of data, from hundreds, thousands, millions, or even billions of things, analyzing it could find patterns that help us work, move, and live much more smartly—at least in theory. Data mining the information we gather from people or car movements and optimizing our transportation systems could help us reduce travel times or congestion, for example, with major benefits for people's quality of life and the environment. Cloud computing systems (the idea of using powerful computer services supplied over the Internet) are likely to play a very big part in the Internet of Things, not least because the amount of data collected from so many things, so regularly, is likely to be enormous.

Who's using it already?

Hive allows you to control your home heating using a smartphone app.

Photo: Smartphone apps are likely to be one of the ways people interact with the Internet of Things. Above: Hive's app lets you control your heating using your phone, wherever in the world you find yourself. Below: Efergy's energy monitoring app keeps tabs on your home energy consumption.

You don't have to look too far to see the Internet of Things in action. Libraries were early adopters, embedding RFID chips in book covers so that people could borrow and return items themselves using self-checkout machines. That gave instant stock-control, better security, and (in theory) the possibility of freeing up librarians to spend more time helping people (in practice, many libraries simply have fewer staff now). Tracking your home-delivery purchases over the Internet is another very basic example: if every parcel is barcoded and scanned at every point of its journey from warehouse to customer, with the scanners all wired to a central database, it's easy to work out where anything is at any time.

Much more interesting examples are also starting to emerge. Hive, a home-heating system launched by British Gas, uses a wireless thermostat that communicates with your home Internet router—making it possible to adjust your heating or hot water using a smartphone app or web browser; the Nest Learning Thermostat, a rival home thermostat system, is more sophisticated but can be controlled by an app in a similar way. Piper, a home management and security system, goes even further: it connects a whole raft of sensors and alarms to a web interface so people can monitor and manage their homes when they're at work or on vacation.

Efergy smart home energy monitor.

Even the infamous Internet fridge is starting to arrive—albeit in rather slow motion. Between 2014 and 2019, Amazon tested a system called Dash, featuring a handheld scanner that you could swipe over products to reorder things when supplies got low. A related idea was to stick simple Internet-connected "Dash buttons" around your home that you could use to reorder things with a single click.

In one way or another, all the big digital technology companies are exploring variations on the Internet of Things. Apple has HomeKit (which turns iPods and iPhones into smart home controllers) and HealthKit (which lets you monitor your health and fitness and, if you wish, share the data with your doctor or hospital through a smartphone app). Google has Home and Fit, which lets people monitor and analyze exercise data collected from wearable sensors and trackers developed by a whole collection of partner companies. Samsung, leading maker of both smartphones and home appliances, sees a great opportunity in linking the two in a system called the SmartThings Hub. Microsoft is also believed to be working on smart home systems linked to its Kinect motion tracker and Xbox gaming system. And Amazon has Alexa.

Good points and bad points

It's easy enough to see benefits from a world in which we connect, monitor, and analyze things much more intelligently. The natural world manages perfectly well without top-down organization, coordination, and control, but our human-dominated planet, packed with over 7 billion people, plagued with problems like poverty, disease, and looming environmental challenges such as climate change, probably can't afford the luxury of hapless, chaotic self-organization for much longer. The benefits of tracking and organizing things seem overwhelming to some people; even so, critics point out equally clear risks of monitoring people and things so much more closely. Do we all want our cars to be tracked at all times? Do we want grocery stores to know even more about what we're heating than they do already? Do we want our homes packed with sensors, keeping tabs on us at all times? There are all kinds of privacy, security, and ethical issues to consider before we get anywhere near the technological difficulties of building something so all-encompassing as an Internet of Things.

Microsoft LifeCam VX-1000 webcam on a table

Photo: Privacy problems ahead? Will an Internet of Things designed for tracking and tracing things turn into a perfect tool for spying on people?

Given that much of the technology exists already, you might think building an Internet of Things is really quite a simple task, but putting everything together is likely to prove much more complex. One problem is that the whole concept has been hyped as a massive commercial opportunity, so lots of different companies are rushing to develop and market competing technologies. That raises the immediate difficulty of getting rival systems to talk to one another. If I buy a smart home-heating system from one utility company, will I be able to control it using another company's smartphone app if I decide to switch utilities in a couple of years time? If I buy myself an Amazon product scanner, will I only ever be able to order products from Amazon? Or will I have to order a different scanner for every different company I buy from? While companies such as Amazon and Apple are notorious for taking a "closed" (or "walled-garden") approach to their products and services (for example, you can only read Kindle ebooks, sold by Amazon, on an Amazon Kindle reader), rivals such as Google and Samsung are notable champions of "open" standards. Whether closed, open, or mixed systems prevail, there's likely to be a great deal of consumer confusion about what works with what, and there's a real risk that the Internet of Things fragments, in practice, into many highly compartmentalized systems—many Internets of Things—that have little or nothing in common.

That's not so surprising when the Internet of Things is so broadly defined that the whole idea verges on the meaningless. A recent British government briefing describes it as an "ecosystem" that links anyone, any business or service, through any path or network, to anything, anytime, anywhere—in other words, defines it so broadly that it includes absolutely everything. Is that a helpful idea? Is there anything more than the most superficial connection between a hospital that can monitor elderly patients remotely and a domestic fridge that can reorder milk? Does it make any sense at all to link such disparate ideas together, if all we're really saying is that everything should be able to interoperate by relying on common systems and standards as much as possible? To put it another way, would your hospital ever want or need to communicate with your fridge?

Although often hyped as a means of doing things more efficiently and saving time and money, there's no guarantee at all that an Internet of Things will deliver cost, energy, or efficiency savings. Does the ability to control your home heating from work make it more or less likely that you will save energy? Will you simply shuffle energy around and use it at a different time? Why can't you leave the job to an intelligent electronic thermostat (a perfectly reliable and efficient piece of technology we've all been using for decades)? Who says you can do it better from your smartphone than a computerized programmer can do it from inside your home? To use a different example, it's absolutely fascinating to track parcels all the way from the warehouse to your doorstep—but do you really need to know anything more than the date when they'll finally arrive? Every extra bit of computer power we use managing, monitoring, and generally fiddling about with the Internet of Things is extra energy for the world to consume. Cloud computing powers the Internet of Things—and is already one of the world's biggest and fastest growing forms of energy consumption. There's a very real risk that, far from helping us reduce resources and use energy more widely, the Internet of Things will simply add another unnecessary layer of micromanagement on top of what we do already—increasing the world's energy consumption overall. It's very telling that data from American homes reveals steadily growing energy consumption despite significant improvements in energy reduction and massive reductions in the energy we need for basic things like home heating.

Smart home technology has been widely available for decades but, so far, has pretty much failed to capture people's imagination or take off in a really big way. Will rebranding it—breathlessly hyping it as the "Internet of Things"—make any difference? Home electrical energy monitors have been around for years, for example, and seem to offer the very compelling benefit of saving money, but they're still relatively underused. Smart homes aside, there are very compelling reasons for businesses and public services to invest in Internet of Things technology—especially if they can demonstrate real customer benefits, cost or energy savings, or other good reasons for doing so. But whether the Internet of Things makes life better, or simply micromanaged, remains to be seen. Libraries and supermarkets are perfect examples: they use more technology and employ fewer people than ever before, but do they serve us better, and do we like them more or less than we did before? Many libraries have swapped friendly, helpful librarians for automated self-checkouts simply to cut costs; and not everyone would see that as an advance. Will the Internet of Things revolutionize our homes, offices, and transportation systems, making everything better organized and more cost-effective? Will the Internet help us control things more effectively—or simply turn people into "things" that can be connected, analyzed, and monitored?

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These two general articles offer alternative, reasonably non-technical overviews:



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Woodford, Chris. (2009/2018) Smart homes and the Internet of Things. Retrieved from [Accessed 2024/04/15]


@misc{woodford_2FA, author = "Woodford, Chris", title = "Smart homes and the Internet of Things", publisher = "Explain that Stuff", year = "2009", url = "", urldate = "2023-08-18" }

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