The advantage of wireless transmission within the home is always being touted as the best solution for all kinds of applications, from entertainment to control. In reality, there are many different approaches to wireless control or data streaming, so here is a (not so) brief summary of some of them.
What is Wi-Fi?
Wi-Fi is the name given to the standard used for broadband networking within your home or office. It allows laptops and tablets to communicate with your network router. Most home routers now include WiFi. Recent Smart TV’s usually include it with your TV so you can easily connect to your home network. It takes a noticeable amount of time to start up, and the range within your home is about 50 meters. In the public domain, free WiFi is often offered at motels and restaurants; libraries and municipalities set up WiFi hotspots. These are all to let you connect your laptop, tablet, or phone to the Internet.
What is Bluetooth?
Sounds like something you get from eating blueberries, but actually Bluetooth is a fast wireless data stream for short distances. With a 10 metre maximum range, it’s designed for communications between two objects in the same room. Because it can stream data pretty fast you can use it for sending commands from your phone to your AV system. It’s handy for wireless headphones, especially if they can link with your Bluetooth enabled phone. It is ideal for streaming digital music from your handheld device to a nearby wireless speaker. Retailers abound with variations on this theme. It’s strictly point-to-point so you can’t use it to control lighting and automation, and it won’t connect you to the Internet. When you see a product that’s Bluetooth enabled, think about wireless streaming of data from a nearby device, usually your smart phone or tablet.
What is X-10?
Way back in the seventies X-10 was far ahead of its time, providing home automation and lighting control with low cost modular units. It sends commands through the power wires in your home to brighten or dim lights, or turn appliances off and on. The system commands whatever is plugged into the module at the wall outlet. Through the turn of the century the company kept innovating, adding devices like a digital recording of a dog, set off by a motion sensor, to scare off would-be burglars, and a relay module that would allow you to receive or send a trigger pulse, making it possible to control things like latches and thermostats. Before they went out of business they even developed pretty good control software, which I think provided the model for all the more sophisticated systems that came afterwards. The X-10 system was clunky and slow, subject to problems (all of which have fixes) and even kind of ugly, but if you can find X-10 modules today, they are still a bargain. For a very small application, like controlling a bedroom lamp or ceiling fan, or sounding a chime with a remote, it is still the best bet. But is it entirely analog, no digital, no Internet Protocol, no streaming.
Those are the three main protocols you’ll hear about. The first two use radio frequencies and X-10 uses powerlines, so I guess, strictly speaking, it isn’t really a wireless system, even though it gets around the necessity of running new cables.
Does My Cell Phone Use Wi-Fi?
Although your cell phone might use Bluetooth to stream to your AV system, or Wi-Fi to connect to your home network, when it comes to making phone calls, it uses radio frequencies to communicate with towers that are located in a cellular pattern across cities and the countryside. These cell networks then communicate with the regular telephone system that runs along the wires on roadside poles. The most common cell network is the Global System for Mobile Communications, or GSM. But then, depending on the brand of your smart phone, it will have its own protocol for apps, for example, the iOS system used exclusively by Apple products, the Andriod system developed by Google and available as an open protocol so that several manufacturers can use it, and the Windows Phone from Microsoft. They all have their own operating features. Then there’s Alarm.com, favoured by Homebuttons and by Carelink Advantage. It has its own GSM frequency for emergency communications, backed up by a landline, so that no message will fail to be sent (see the tab Aging At Home on this website to find out more about Carelink)
Wireless Audio Video Applications
Every aspect of your home entertainment system can be wireless except electrical power (so far).
This is the line-of-sight wireless protocol that uses high frequency infrared light pulses to send commands. It’s on all remotes, and it’s the reason you have to point the remote at what you are trying to control. Some remotes use wireless communication, either instead or in addition to IR, to get around the line-of-sight restriction. To get IR signals from one room to another, or through a solid material like a cabinet door, the industry has developed IR repeater systems, with a receiver in one space to see the beam from the remote and an emitter in the other space to relay the commands to the component you are controlling. IR repeaters require a hardwire connection between the receiver and emitter, but they can piggyback on coax cable if there is already an existing connection between the two spaces (i.e. your TV cable).
If you program a universal remote with a one-button press to turn on several components and set them up (e.g. Watch Movie button turns on TV, puts it to the right input, turns on the DVD player and starts it playing) you have to remember to keep the remote aimed at the devices to give it time to send each of a series of commands through the IR rays. At least that’s the case if the remote uses IR; it might communicate wirelessly to its own base station, which then in turn sends IR codes to the components.
This protocol (see above) allows you to connect to the Internet without running cables, so you can access things like You Tube, Netflix, Internet Radio. It’s commonly used for laptops. Smart TV’s usually have a WiFi receiver and you can easily link to your wireless router if you know the password.
This allows you to link directly from your Bluetooth enabled device to a receiver so that you can stream the videos or music files you have stored on your personal device without using the Internet.
Usually some form of WiFi is used, often proprietary, with a receiver built in to the speaker communicating with a transmitter on the source component. The most common application is with TV Soundbars which are hardwired to the TV audio output, but send the subwoofer frequencies to a free-standing sub across the room without having to wire it directly. There are also devices available with analog RCA connectors on the transmitter and speaker outputs on the receiver so that you can use it with your existing source component and speakers. The thing to keep in mind is that, although the audio can be sent wirelessly, the speakers need to be powered by an electrical outlet. Some manufacturers get around this by providing a special amplifier for the rear speakers which communicates to the base station wirelessly, but draws power from an outlet and sends signals through speaker cable to the speakers on its side of the room.
Most security systems can work with wireless sensors that communicate with the panel. Some hybrid systems are available which combine hardwired and wireless zones. These systems use proprietary protocols to preserve security and continuously poll the devices to ensure that they are still communicating. The devices, such as contacts and motion sensors are bulkier than their hard-wired equivalents because they contain batteries.
The Homebuttons recommended solution uses 2GIG Go Control (although we also provide and install security systems from DSC, Honeywell, etc.) because of the many advantages it offers the homeowner. The sensors communicate via narrow band radio frequencies, as other wireless systems do, but it also incorporates Bluetooth and WiFi to provide options for the homeowner to communicate with the system and Z-Wave home automation devices.
Control of lighting and environmental conditions within the home has its own needs which differ from those of voice communication or streaming of entertainment. Within the home the devices that sense changes and control devices such as lamps, air conditioners and even door locks are built-in rather than mobile. You want a home automation system to be responsive, not only to commands you might send from your tablet but from triggers. You open a door from the garage, for example, and lights turn on, the thermostat adjusts for occupancy. You turn in at night and the doors are automatically locked, the security system is armed and all lights are turned off. It’s automatic. So you need communication between devices that is not just from one point to another, and is not going to hog all the memory on your computer or the bandwidth on your home network. Special wireless systems, usually using radio waves (but not always, see X-10 above) have been developed for these purposes, going by names like Z-Wave, Zigbee, CEBUS and Insteon. What most of them have in common is that they are based on mesh networks, in which each device acts as a repeater to relay information, so that no one device is too far away to communicate. But these types of networks are being challenged now by the Internet of Things, meaning individual items (such as a light bulb) that contain miniature computers within them and utilize Internet Protocol to actually use your home network to communicate (eating into your Netflix bandwidth). There are a lot of different ideas and, like Beta vs. VHS, the technology that eventually predominates will be the one with the best marketing and therefore the widest applications in the real world.
Cordless Phones, Baby Monitors and Garage Door Openers
These devices have been around for a while and are restricted to a specific frequency range. To provide some security against someone tapping the line, they usually use “frequency hopping”, jumping from one frequency pretty much at random within the allowable bandwidth or frequency range.
How Dangerous Is All This Radiation?
I don’t know. And I’m not sure anybody does. What I do know is that radiation decreases with the square of the distance from the source so you get more radiation from the cell phone at your ear than you do from the tower in the field. And there is more radiation from light than from Wi-Fi; if radiation is harmful, turn off the lights, not the laptop. Of course, cancer is the big worry. For something closer to an expert opinion, check out http://www.cancer.org/cancer/cancercauses/radiationexposureandcancer/radiofrequency-radiation
Everything. By the time you read this, there have been new products and applications developed and brought to market that weren’t there when I wrote it. I used to think, back in the twentieth century, that future-proofing meant hard-wiring everything, but now I’m not so sure. Wireless technologies are improving faster than the eye can see (pun intended). I still recommend comprehensive prewiring wherever possible when you are building a new home because a copper wire provides a dedicated and secure path for data from one point to another. And even if you rely on Wi-Fi for all your modern entertainment needs, you may still require a hard-wired Wireless Access Point to get around interference from concrete, steel, foil weather barriers, etc.
Here’s a final disclaimer that probably should have been at the outset. These are just things I’ve gathered from working with all this stuff and I have never done any lab work or comparative studies. When a new product comes on the market it is touted as the best solution and the manufacturer will tell you why. It’s from the literature that comes with the products and from the experience of installing things that I’ve gained my knowledge, such as it is. I could be wrong.