Aeotec Range Extender 6	Aeotec Range Extender 7

Overall Rating 

A strong mesh network is the backbone of Z-Wave Plus home automation. While it’s true that under normal circumstances you should not need a range extender/repeater, most normal humans probably do. This is a religious war, especially for those who would say you don’t. My bottom line, it wont hurt and it will probably help.

Any Z-Wave Plus device (mostly) that is constantly powered should/will act as a repeater. That is one of the advantages of Z-Wave Plus. This means in-wall switches, plug-in modules and other powered devices can be used to extend and improve your mesh network.

So why a range extender like the Aeotec?

When it comes to Z-Wave Plus in-wall switches, even though they are repeaters, they are jammed in the wall, surrounded by wires and often other devices. While the wires don’t matter so much, they can act as reflectors and directors of other signals as well as attenuate the signal from the switch. Once a switch is in the wall, it’s anyone’s guess what is happening. This could be negligible, but you don’t know. Also, the in-wall switch probably doesn’t have a power amplifier or a tuned antenna.

So wouldn’t a Z-Wave Plus plug in module get around this and add the benefit of not losing wall outlets? Yes – probably. Whatever effect your homes wiring would have on the plug-in module would be the same as the effect on the range extender. However, I would be inclined to believe that any device that is specifically built as a dedicated range extender has been designed with one thing in mind – being a range extender.

While a plug in module has the properties of a repeater, it is built to be a plug first and then to take advantage of the Z-Wave Plus full power capabilities. It probably doesn’t have a Power Amplifier and depends on a standard antenna which probably isn’t an RF tuned antenna. This can affect the distance and signal quality

FLiRS, Beaming, Power and Antenna’s

Certain battery operated edge and barrier devices (locks, thermostats, blinds, etc.) take advantage of a Z-Wave technology called FLiRS, which stands for Frequently Listening Receiver Slave. FLiRS allows the product manufacturer (particularly battery devices like locks) to control how often the device wakes up to check for messages. If a Z-Wave controller or other node in the network needs to communicate with a battery-powered device such as a door lock, the controller sends a special beam signal. The purpose of this beam is to wake up the FLiRS device.

An important side note is that not all repeaters are capable of beaming, and beaming is an important factor in getting the message through to a FLiRS device. You can think of beaming as message delivery assurance. A beaming device will continue to send the message to the FLiRS device until the message finally gets through. The amount of time it actually takes is dependent upon how often the FLiRS device will awaken into the partially awake mode.

The FLiRS device alternates between sleep mode and a partially awake mode at a rate between once-per-second to four-times-per-second (this is the manufacturers choice). When the FLiRS device receives the beam, it  becomes fully awake. Once awake, the device communicates with the controller or it neighboring devices using the standard Z-Wave protocol. If the device does not hear a Beam it goes back to sleep until it partially awakes again to listen for a Beam.

Most battery powered devices can simply stay asleep until they are locally triggered to send a message. A wireless door/window sensor, for example, only needs to wake up when there is a state change at the device. It doesn’t need to listen for commands, since it doesn’t actually do anything other than report status. A door lock, on the other hand, must also receive commands (lock, unlock, change codes, etc.). FLiRS takes care of the wake-up-to-listen problem, and beaming makes sure the message is waiting for the FLiRS device when it’s ready to receive.

Therefore, it’s important that the repeater you choose is Beaming Capable, or else you will lose those all important messages that are being sent to your lock or other battery operated devices.

Now we have ticked a major box… my repeater has beaming capability. Shouldn’t that be enough? The answer is, well… maybe.

The next area that you may be concerned with, especially if you have FLiRS devices that are dropping offline, is the power and antenna placement of the repeater. As I mentioned at the top of the article, switches and other devices that are not dedicated range extenders do the repeating as a hobby. In my mind it works like this. If I decided to build an in-wall switch, I would want to build the best in-wall switch on the market. Of course I would design it to be capable of supporting beaming for FLiRS devices. But I’m going to focus all of my attention to the features of the switch. If I were to build a Range Extender, I would be focused on building the best on the market. I would be looking at antenna radiation pattern and gain.

I wouldn’t expect an in-wall switch manufacturer to be thinking of any of these things, other than ‘my Z-wave chip supports beaming’. I’m not knocking them for it and, in fact, I’m happy that they include this feature in their switches. I’m only pointing out that it ‘may‘ not be enough.

To my knowledge the Aeotec Range Extender has 1) an optimized antenna design, and 2) a power amplifier. There aren’t a bunch of other electronics crammed in around the one thing you’re looking for – a Range Extender.

Bottom Line

If you are not having problems with your Z-Wave network, don’t buy a range extender. You don’t need one. But if you’re reading this article because you’re having problems and asking yourself, “shouldn’t my mains-powered devices be doing this already?”, I would say, get a range extender. Give it a shot. My guess is that your problems will get better.

My recommendation is to get two. One to place within 6 to 12 feet (2 – 4 meters) from your hub, and one about 30 – 45 feet (10 – 15 meters) from your hub. This will create a solid backbone for your network and ensure that all devices, constant and battery powered have a solid connection into the mesh.

Of course, all of this is based on my own experience, your mileage may vary.

If you’re having problems with Z-Wave locks – this is a popular method for fixing the issues. 

Sources:

Z-Wave FLiRS – Enabling Wireless Smart Door Locks and Thermostat

Other Useful Information

If you want to know if your device is capable of Beaming, you can check it out from the certification information on the Z-Wave Alliance website.

1. Go to the product search page.
2. Search for the product.
3. Once you find the product, click on the View link next to Z-Wave Protocol Implementation Conformance Statement:  
4. Under Product Information, you will see Supports Z-Wave Beaming Technology? Yes or No