In its most simplistic view, a Smart Home is a collection of Sensors and Actuators, coordinated by a Controller (see this post if you want the full story):
- Sensors measure physical values and sends these data values to a controller.
- Controllers make decisions based on the sensor data, and in turn send control signals (which is data as well) to one or more actuator.
- Actuators produce the desired physical effect based on the commands sent by the controller.
Sensor and control data need to travel from one device to another in a reliable way, otherwise the desired effect will never happen, or happen too late. This makes the “pipes” that carry data in your home essential for the correct operation of the whole home, and can make or break your automation system. These “pipes” that I’m referring to are in reality all the components of your home’s communications network. We use the term Local Area Network or LAN to refer to it. Today we’ll talk about home LANs, and what they need to do to ensure all works without a hiccup in your home!
We’ve said before that many dissimilar subsystems in your house can become one smart home system, as long as they can communicate. A subsystem is typically specialized on an aspect of your home, like security or temperature control. In order to communicate, some subsystems have a proprietary network that carries data for it; some of them use open standards. Others don’t directly communicate, but third party products will allow them to inform what is happening and accept orders to be carried out. These days, practically all subsystems offer some sort of ‘gateway’ or ‘hub’ that allows interacting with them using a Local Area Network or LAN, to keep it short. Now Imagine that this LAN is like a city transit system: the better transportation the city has, the easier it is to do business in that city.
Just like in a city, not all types of traffic are the same. Some users need to move really fast, some others need to move heavy cargo, and so on. In the smart home, the amount of control data that flows inside the home LAN is not large, but it needs to be able to move from one point to another as fast as possible. If doesn’t, the system feels sluggish, so keep this in mind. There are other types of traffic, where the amounts of data are much bigger, but don’t have too much trouble with small delays… I’m talking about photographs, videos and music from a variety of sources and formats… let’s call all that your digital media. I can bet you that digital media will certainly use the majority of the capacity of your network. Given that home automation and digital media data will be constantly travelling the home network, a reliable Home Automation system requires a solid Local Area Network that is capable of giving the proper priority to each type of data… the computer speak word for this concept is Quality of Service, or QoS for short. QoS allows creating the electronic equivalent of carpool lanes, highways, bicycle lanes, and pedestrian streets. Hey, wait a second, all modern networks are wireless and handle all communications intelligently, right? So why should we even worry about the network? You just buy the components, put them together and you are done, no? Even better, my Internet Service Provider (or ISP for short) gave me a box that does the WiFi, has four network thingies at the back to connect the old stuff that is not wireless. I’m done, right?
It is very easy to start thinking along those lines, and very quickly move on, thinking that this network business is a done deal. Well… a home network that did not receive much attention will kinda keep data moving… until it won’t. From time to time some homeowners realize that the network has some role in their automation and tell me: “hey, the gateway I got from my ISP is not good, so I bought this super-duper router from brand X –the one that cool people use-, I’m sure that’s all I need to have, ‘cus it looks like an angry alien and the box says that it is gamer-ready and handles 4k beautifully”…
While networking has improved a lot since the dark ages of the 80’s, it is still not a “throw a few bits and pieces together and it will self-organize” kind of thing. It helps to keep in mind that proper network planning is essential for the success of almost everything else in your smart home. In my opinion, the key points to understand are:
- Your network is the foundation for your Smart Home.
- The equipment that your ISP provides is not necessarily the best one for your needs.
- Use WiFi and wired connections where they work best.
- Wired connections are safer and more reliable than wireless ones, but still need to be used carefully.
Let’s talk a bit about each one:
Your network is the foundation of your Smart Home. Continuing with the traffic analogy, the most advanced countries normally have the best transportation systems. They allow businesses to service customers, produce and distribute goods in an efficient way… helping to keep the costs down and allowing businesses to scale up when needed. Well, Smart Home networks behave similarly. A good network will allow you to grow, and will save you money. A bad one will give you headaches on a regular basis, sometimes even giving the impression that the automation system is failing. This is where an installer (or you) have to spend time looking at the problem, which at the end will cost you money.
In my opinion, a good smart home will almost always have a substantial networking component, and any enhancement always considers what your network can do. A simple thing such as the number of cabled vs wireless devices can make a difference: How many network connected home gadgets you personally had ten years ago? I can bet you that there were probably just 2-3: Your laptop, maybe a desktop, and possibly some sort of early-days electronic organizer… Remember the Palm Pilots? Now think about how many “smart” devices you have today, starting with the well-known laptop, but I’m sure you now have a tablet, some sort of smartphone (with Android or iOS) for each member of the household, plus an ever-growing list of nice gadgets like: network printers, game consoles, TVs, network DVRs, connected speakers, carbon monoxide detectors, robotic vacuum cleaners, projectors, lights, surveillance cameras… even doorbells and coffee makers can be networked! The list can be surprising. Considering a household with only 3 persons, the number of devices on the network can easily get to 50 or more. Just by wiring the most data-heavy devices, you could get a nimbler experience.
The equipment provided by your ISP is not necessarily the best for your needs. ISPs are in the business of moving data in and out of your home. Moving data inside of your home is your problem. In order to connect you to the internet, ISPs install a device that can have many names, I’ll call it a residential gateway for now. Its main component is a cable modem, which is the actual piece that connects you to the ISP network, it receives the most attention from your ISP. You’ll probably find that almost all ISP provide some sort of additional features in their residential gateways, like:
- A router, which is the part that decides what data from the outside comes inside your house and vice versa.
- A wired network switch, in charge of moving data from one wired port to another, based on knowing which devices are connected on each port. Although its function may sound similar to a router, it moves data super-fast based on physical addresses in you LAN, and can only handle a few of those per port, ideally only one. The router also switches data, but it does it from your LAN to the ISPs network, and does it based on logical addresses at a slower pace.
- A WiFi Access point. As you can already guess, this is the component that broadcasts WiFi signals.
It is now increasingly common to find additional components, which are mainly software:
- Firewall. This device is mainly used to isolate the network inside your house, from the internet, which we already know is full of hostile data and evil people.
- DLNA server, normally used with an external USB connected mass-storage device. This combination allows to store digital media like pictures and music in a central location (a hard drive connected to the residential gateway), so that DLNA compliant devices can get this media and play it anywhere in the house.
- Download manager. A piece of software that allows you to download very large files onto the aforementioned USB connected mass storage device. BitTorrents, anyone?
- Network print server. This software allows to connect one non-network enabled printer to an available USB port on the gateway to make accessible from anywhere inside your home.
What is wrong about getting all the above in a single box? The ISP is giving you everything in this gateway for free (really?), so why not use all of it?
Well, there are a few reasons:
ISPs use this kind of device to sweeten their offer, but they need to keep the cost of the gateway low to make it profitable. The majority of the gateway development money goes to the core purpose of the device, which is the cable modem. The rest of the residential gateway get less attention, so this kind of equipment works well only for smaller installations. In addition, the whole device needs to be contained in a single box, to allow for quick deployment. For Wi-Fi in particular, this can cause problems due to its typical location in the house, which is close to the main electrical panel, normally in the basement. Wi-Fi uses radio waves that lose power as they travel across air, and especially when it passes through walls. Dead spots at the farthest places of the top floor of the house house are likely to exist. A common solution is to turn WiFi off on the ISP-provided cable modem and install a separate hardwired WiFi access point close to the center of the house. While this helps a lot, sometimes the walls and distance from the access point still leave dead spots.
2017 was the year in which a number of home mesh access points appeared, these feature two or three access-point-like devices that work together to extend the WiFi coverage. The basic idea is that one of those devices connects to the ISP-Provided Residential Gateway, and one or two additional units located in appropriate places in your home extend that signal to where it is needed. Although most of them do a good job at bathing your home in a strong WiFi signal, not all of them are really efficient at moving data from the satellite access points to the central one. The reason this happens is simple: it is common for satellites to also use WiFi to talk to the central access point, which effectively reduces the effective speed at which you can send and receive data. There are many tricks that can be used to stay away from the wires, but the ones that will serve you better for many years are those that connect the satellites with the central device using a hardwired connection.
Use WiFi and wired connections where they work best. WiFi It is very convenient, and it works great, but should not be used as if it was the only solution. While it is true that in recent days the latest WiFi standards claim theoretical speeds (7 Gbps) that are clearly over the raw speeds of the most common wired network solutions (1 Gbps); it is important to remember that wired solutions consistently give you 1 Gbps per port. In contrast, WiFi gives you up to a certain speed in open air, which has to be shared by all nodes that are close by. This has very important implications, especially when we consider that all wired nodes are typically connected to a switch. As I mentioned earlier, a hardwired switch briefly connects the ports of only the devices talking at any given moment, allowing several device pairs to be sending data at the same time, which is not possible with WiFi. Another point to consider is that WiFi is based on radio waves that travel across open-space, using specific frequencies in the electromagnetic spectrum. A certain number of frequencies are grouped and used in what is called a band. No rock & roll here, just some good ol’ radio frequencies, ok? In particular the 2.4 GHz band, in which the b/g and n WiFi standards operate, are especially crowded. This happens because not just your home, but your neighbor’s networks need to share that band. The 2.4 GHz band also happens to be one of the bands that don’t need a license to be used, so a lot of other technologies also use it, like Bluetooth, some cordless phones, and essentially anything else that needs to be wireless without requiring a license to operate. The 5 GHz band, used by the a, n and ac standards is a bit better in terms of it being less crowded, but at those frequencies the radio signals are much more difficult to work with, and have less coverage. I’ll be talking about this in more detail in an upcoming post.
Ok, ok… Which devices should be wired? Well, here are a few that need consistent pipes: Smart TVs with streaming apps, game consoles and surveillance cameras. It is very common for people to complain that their movie is not streaming smoothly, only to discover that they are using a wireless link on a very crowded WiFi channel. I’m not trying to demonize wireless networks, I’m just trying to make a point about them having a number of use cases where they fit very well… there are other use cases where wired is the way to go. A lot of people tend to get discouraged by the notion of having to install wires, but please have in mind that the small hassle and cost during installation is nothing to the frustration that you get when you finally have a little time to wind down after a furious week, and the movie does not stream well. Unless your home presents a particular challenge, like being too old or built with a lot of concrete or insulation on every single room, a good installer will keep after install patching to a minimum… of course, you are building a new home, it is a great time to install two runs of CAT 6 (or at least CAT 5e) network cable from a central location near the main electrical panel and every single room in your home. Think of one network port anywhere where you’ll have a TV, a music system or a desk. I recommend to also install wired ports anywhere where you will have a camera, specially for those that will be inside your home. We’ll talk about outside cameras in just a few paragraphs.
Home Automation data is not particularly needy of great speed, but it requires its data to arrive fast to its destination. Wait, isn’t the speed of the data directly related to how fast it is transmitted? In part yes, but there are other factors that are not data speed that also influence how fast that data arrives at its destination: Access to the transmission medium, and number of times that data has to be re-transmitted. In the communications industry there is a term called latency used to refer to this. WiFi networks can sometimes get into situations where the different house networks in a block get into each other’s way for periods that last from just minutes to weeks, raising the latency to the point where the network is not usable anymore. I could go on for hours talking about these and many other technical aspects but I prefer to keep it short and then discuss it at another episode. Typically, you want all automation-related equipment on wired Ethernet, as well as Streaming devices like TVs, Game consoles, and devices that need to have low latency or transmit in great volumes. Tablets, Laptops and phones are meant to be used wirelessly, of course.
Extraordinary conditions may make it necessary to run controllers on wireless networks, but those should be exceptions, at least in my opinion. When designing an automation solution, you or your integrator should spend enough time understanding the network in the house. The last thing you want to happen is to invest money on a project that will not shine because it was built on a network that is not able to move its data… remember, automation is really about moving and converting data.
Wired connections are safer and more reliable than wireless ones, but still need to be used carefully. C’mon! What’s the problem now? Well, although wired connections are reliable and robust within your home, it’s imperative to be careful when exposing a connection to your network outside of your home. It is very common to install network cameras these days, they have a lot of advantages. Some of them, can even be powered by the network switch that they are connected to, using what is known as Power over Ethernet, or PoE for short. Man, we love our acronyms! OK, but what is the problem? I’m getting there: when you have an exterior camera connected to your interior network, a person that really wants to peek inside your home will just disconnect one of those cameras and connect a laptop to your network, without having to be inside. Considering that a number of automation controllers assume that a request is safe if it comes from the local network, the intruder will probably be able to send commands to your controller. There are a few ways in which the industry addresses this, but by far the easiest is to logically separate the ports used for the cameras so that they appear to be in another network; if someone tries to sneak in using a camera network port, they won’t have an actual entrance to the home’s control network. This is implemented using something called a VLAN, which almost none of the residential gateways properly support today. Another way to address it is to use a modern camera that sends high quality video over coaxial cable, using High Definition Composite Video Interface (HDCVI) .
By now you have probably realized that the network is of paramount importance, and that it is essential to build it in a way that will allow you to build your home automation as well as the services needed for your digital living. Talk to us today, we’ll be more than happy to help you get the best network for your home.