A Guide to Smart Home Protocols
Last updated
Last updated
With the explosion of the smart home in recent years, several smart home protocols have appeared or imposed themselves. Let us be clear right away, the various protocols I will present to you here are all good. It will simply be necessary to do a thorough analysis of the need before you start. Then let's look at the most interesting protocols of the moment.
This is the protocol that has established itself over the years as the master smart home protocol. It is not for nothing that the latter has imposed itself, it simply has many assets that make it a reference in this field. Indeed, the Z-Wave is a bidirectional protocol at first. In other words, it allows peripheral devices (presence detector, opening detector, relay…) to give a status feedback to the smart home hub. This means that if your box sends an order to the sensor, the sensor will inform the box that it has received the order and executed. This makes it possible to secure the action in the first instance.
Speaking of security, the Z-Wave is also a protocol that can secure its data exchanges. Most of the latest Z-wave plus devices allow this security. Without getting into the technique, the security mode establishes encryption in the frames exchanged between the smart home hub and the peripherals. It is therefore impossible to intercept a frame to read its information. Note that it is possible to mix secure and non-secure devices on the same installation without any problems.
Another real plus of the Z-Wave is its operating principle based on a network mesh. This improves the security of your network since a device can have several possible paths to contact its controller and vice versa. In addition, this network mesh makes it possible to drastically extend the network's reach since all the devices powered on the mains supply act as a "repeater" for a device a little far from the box.
The signal range, let's talk about it, the announced range is purely indicative since, like all wireless protocols, this range is necessarily influenced by the environment of the building to be controlled. So the theoretical range does not matter, especially in a protocol like the Z-Wave or the mesh size necessarily increases this range.
Reading this speech, you can understand why Z-wave is imposed in home automation. However, there is still a black spot on the board, which is the price of Z-Wave devices. Here again, if we move forward in time, more devices exist, more necessarily the prices decrease, however, today, a Z-Wave device costs on average 50€. When it comes to installing a sensor on each door of the house, the note can very quickly rise…
The Zigbee is a protocol with very similar capabilities to the Z-Wave. Also having a mesh network, it has a large reach and some redundancy. The Zigbee is also Open Source. This may explain why several brands have chosen this protocol over another. Philips Hue, Smartthings, Innr, Xiaomi, Aqara… To name but a few, have chosen this protocol for their smart home ecosystem.
Let's face it, smart home is fantastic… It's not on my blog that you'll find a contrary opinion, but managing battery changes can quickly become a pain on an installation that had several dozen sensors. That's where Enocean comes in! Enocean is a great home automation protocol that offers devices that are self-sufficient. Indeed, Enocean devices have the particularity of generating their own energy reserves which then allows them to restore status information to the home automation controller. This is done via fairly simple and ingenious principles such as kinetic energy or solar energy.
On the operating principle, the Enocean protocol uses a frequency of 868Mhz and has a status feedback as for the Z-wave and Zigbee. It is therefore a protocol that can also be very interesting in a home automation installation.
The Edisio protocol is another smart home protocol that works on the 868 MHz frequency band, like the Z-wave, the Zigbee or the Enocean, but all these protocols coexist very well together.
The Edisio also works according to the mesh principle. This makes it an interesting protocol when it comes to installing a module far from the smart home controller. Because Edisio devices are repeaters for other devices, it is possible to greatly extend the coverage range up to 200m in distance.
Another point, more focused on the elegance of the peripherals, the Edisio peripherals, in particular the switches, are neat and design, which can then be integrated into an interior whatever the decoration! Finally, Edisio products are cheaper than Z-wave devices for example.
A pioneering frequency in smart home, the 433Mhz is not dead! Indeed, we can't even imagine the large number of devices that use this technology. Your electric gate, your garage door, your weather station, your roller shutters… The 433Mhz peripherals are numerous in our houses, the 433Mhz is well and truly at its best! As you will have understood, the brands that use this frequency are numerous. To name a few, Oregon or Chacon are big names in the smart home and offer devices that operate in 433Mhz.
Compatible with a very large number of smart home hub, the 433Mhz is not decoded in native, it requires an RFplayer or an RFXCom that will interpret the frames and restore them to the smart home hub.
One of the great advantages of 433Mhz modules is the lower cost. On the other hand, this protocol is not flawless, easily interpretable and not very secure. This is one of the reasons why the remote controls of an automatic gate operator or garage have a rotating code. Another problem with 433Mhz devices is that they do not offer state feedback. It is therefore difficult to know if the requested order was actually received and executed by the device….
Beyond that, devices such as Chacon or Oregon devices if they are not dedicated to security-related tasks are an excellent alternative. I myself have several devices in my installation that work perfectly!
Now that we have listed the protocols that prevail on smart home scenes, let's talk about security. If the 433Mhz does not excel in this field, the Z-Wave, on the other hand, offers in its Z-Wave version plus a secure association that encrypts exchanges with the smart home controller from start to finish. It is then impossible to decipher a frame intercepted between a device and the box or vice versa. The Z-wave is the most advanced on this point. The Enocean, does not fully encrypt, but uses a key system generated with unique IDs so not so easy to decode. The Zigbee offers exchange protection somewhat similar to the Z-wave with 128-bit AES encryption. The Edisio protocol also offers data exchanges via undecodable frames, so only the 433Mhz is behind on this point, although most remote controls that operate in 433Mhz have a rotating code to secure everything.
From an economic point of view, it is the 433Mhz peripherals that win the game. Although some Zigbee devices are becoming accessible with the arrival of Xiaomi devices. The Chinese chose Zigbee for its peripherals with, due to the Chinese product, very low prices! Then there are the Edisio devices, which are also accessible, but a little more expensive, and finally, at the top of the table, there are the Z-wave and Enocean devices. The price of Enocean devices can be explained by the originality and complexity of the on-board self-powered mechanisms. Finally, Z-wave, the king of smart home protocols, is beginning to see affordable devices coming on the market.
