Choosing a Wireless Protocol for Home Automation

Another article about HA protocols, if anyone missed the previous thousands of articles on this topic. Interesting point of view here, is the author calling on the death of zigbee. Go Thread!?!

Pffah. Iā€™m still team Betamax.

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Interesting article. I didnā€™t see anything that predicted the death of zigbee, explicitly or implicitly. The author says it may be an excellent match for closed systems. The main point he emphasizes is that if you are designing a device to be sold into an open system, you can run into problems with zigbee interoperability. Which is certainly true.

The one factor that he didnā€™t consider, though, which is really important, is the number of devices that can be controlled in a single home. One of the huge advantages that zigbee has is the number of devices that can be added to the mesh. WiFi often tops out at less than 50. Z wave has a hard limit of 232. With Bluetooth it depends on the topology, but it can be as few as 16. Zigbee can support thousands. Thatā€™s why zigbee has been the protocol of choice for lighting applications.

So I thought it was an interesting article, and accurate for the specific perspective the author is using, but the device count factor does matter and I was surprised to see that not mentioned.

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The article really did hype of thread. I like zigbee since it is the only open standard out there.

There needs to be a single standard like 802.11 with wifi. A lot of issues with home automation would be lessened if we had a singular standard everyone rallied behind.

I will use this xkcd again:

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The future of ZigBee is uncertain. Its power efficiency has been surpassed by Bluetooth Low Energy and several new or upcoming protocolsā€¦its poor interoperability makes it hard to see it as a major home automation protocol in the future.

I donā€™t know any details, butā€¦
http://z-wave.sigmadesigns.com/design-z-wave/z-wave-public-specification/

My observation/opinion is that there are too many zigbee ā€œstandardsā€ and incompatibilities, Iā€™m sticking with z-wave :slight_smile: I have always been a fan of Bluetooth so eventually Bluetooth Smart Mesh could replace zwave for me.

If the author had said a ā€œmajor DIY home automation protocol for low-cost systems in the future,ā€ that would be reasonable.

The thing is, zigbee already is the major home automation protocol for closed high-end systems like control 4. Thereā€™s no sign that thatā€™s going to change. If youā€™re going to limit device choice to officially certified devices and have it professionally installed, zigbee still has a lot of benefits.

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Well, Iā€™ve started reading it until I came across this:

Z-Wave uses the IEEE 802.15.4 physical radio standard

and realized that the author is an ignorant moron. :smiley:

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Author is not wrong. The 802.15.4 standard does cover communications on the bands zwave uses. It is just rarely stated.

Edit: Removed a link since it was not relevant.

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That is a new development. I think it is in response to Zigbee and Thread both being open-source.

Zigbee since open was ruined for a bit. First gen lowes zigbee was proprietary (as well as many others), but lately more companies are choosing the base open standard.

Yes, he is. Do not confuse frequency band with the protocol. Thereā€™s a lot of different standards that use the same frequency bands. For example Bluetooth, Zigbee and WiFi all use 2.4 GHz. It does not mean they use the same radio protocol. Z-Wave has nothing to do with IEEE 802.15.4 and it never will. :sunglasses:

Now that they have published the API, the Z wave alliance has a new official statement on open standards:

http://z-wave.sigmadesigns.com/why-z-wave/

By utilizing the ITU 9959 global radio standard and offering a publicly-available application layer for product interoperabilityā€¦

And hereā€™s the ITU doc. Note that the standard is specific to sub 1GHz transceivers, so not zigbee. :wink:

https://www.itu.int/rec/dologin_pub.asp?lang=e&id=T-REC-G.9959-201202-S!!PDF-E&type=items

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So whatā€™s your point? Yes, ITU 9959 has been an open standard for a while. What does it have to do with 802.15.4? Z-Wave does not use IEEE 802.15.4 physical radio standard. Period. End of story. :sunglasses:

Right. Zwave is using ITU 9959. Zigbee is not.

Zigbee is using IEEE 802.15.4. Zwave is not.


Whatā€™s new is Z wave now claiming to be an open standard, which they can do since they published the API in September 2016. You still need the proprietary chip in order to get a device certified as Zwave, which is walking a narrow definitional path. It shows that ā€œopen standardā€ has become a marketing thing, I think.

For years the two biggest obstacles for Z-Wave adoption by home-automation developers were: 1) The chips are only available from a single source, Z-Wave owner Sigma Designs, and 2) The protocol was considered ā€œclosedā€ and unavailable to the public.

With its recent decision to open up a big chunk of the Z-Wave protocol, Sigma Designs has eliminated number 2 ā€¦ mostly.

As of the announcement, the interoperability layer of Z-Wave is now published into the public domain.

The software stack does not concern me as much as the patent situation (which includes US8117362 B2). The usage of ā€œopenā€, in context of ā€œopen sourceā€ has never included Trademark. If a company wants to create a certification for the usage of Trademark, there has never been much objection to that; I would even say that it has been encouraged.

When looking at Z-wave, I find the patent problem to be a bigger barrier at this time.

Let me caveat the above with the following statement; so much of the information on z-wave has been closed for so long that there are numerous misconceptions about it, as well as probably a few dark corners that no one has noticed yet. Its hard to predict how much of a barrier those unknowns are (obviously).