Amazon Patents ZigBee Over Power Cable to Adapter

Interesting article. Amazon has been awarded a patent to send ZigBee over the power cable to offload the ZigBee radio to the power adapter instead of from the device. The main purpose would be to separate possible interference from WiFi/Bluetooth and the ZigBee signal.


I personally think this is one of the reasons that Amazon went to zigbee for the echo plus (even though this particular patent doesn’t apply to the echo plus, it’s for the “Amazon key“ system where the camera is the hub). Z wave is owned by a single company, now Silicon Labs. It really limits what other patentable technology can be developed for it. But zigbee is an open standard. That lets a company like Amazon invest in improvements for their own devices while protecting them with patents if applicable.


The article’s title is a little confusing / misleading - enough that they had to add this to the text of the article:

All this patent covers is extending the Zigbee radio (antennae) by sticking it inside a custom-made power cable (or other external cable, in order to reduce interference between competing signals from different radio modules all crammed inside the same IoT device.


I was wondering if anyone else would interpret the Patent that way.

That’s a huge difference than actually running ZigBee over power-lines.

It is a shame, though, that Amazon patents this. It’s a rather “obvious” antenna optimization.

Sigh. All together now: “hardware is hard.” Indiegogo is full of projects which will never be completed because they take obvious ideas but they don’t yet have a working prototype and they don’t understand the issues involved in creating one.

The idea may seem conceptually obvious, the actual implementation is far more complex. There have been people working on something like this for five years, but not succeeding. ( including, by the way, Google with their on router which was supposed to do something like this, but didn’t.)

Julie Jacobsen does a good job of covering industry, but she’s not an engineer, and like most journalists she sometimes oversimplifies coverage of technical issues.

Look at the actual patent.

The system of claim 2, wherein the first set of wires comprises a power wire and a ground wire; wherein the second set of wires comprises a power wire, a ground wire, a data plus or electronic device receive wire, a data minus or electronic data transmit wire, and an ID wire; and wherein the ZigBee radio module is configured to communicate data to an external device using the universal asynchronous receiver/transmitter…
The system of claim 1, wherein the ZigBee radio module further comprises one or more tri-state buffers and a first ID pin comprising a first resistance value, the tri-state buffers configured to output a value of one or more of: (i) 0; (ii) 1; or (iii) high impedance of equal to or greater than about 5 megaohms; and wherein the camera further comprises a second ID pin having a second resistance value that is greater than the first resistance value in an inactive state.

My guess is that’s two years of work right there.

And this is 100% not an “antenna optimization.” Again, see the actual patent.

The bus(es) 620 may include at least one of a system bus, a memory bus, an address bus, or a message bus, and may permit the exchange of information (e.g., data (including computer-executable code), signaling, etc.) between various components of the electronic device(s) 600. The bus(es) 620 may include, without limitation, a memory bus or a memory controller, a peripheral bus, an accelerated graphics port, and so forth. The bus(es) 620 may be associated with any suitable bus architecture including, without limitation, an Industry Standard Architecture (ISA), a Micro Channel Architecture (MCA), an Enhanced ISA (EISA), a Video Electronics Standards Association (VESA) architecture, an Accelerated Graphics Port (AGP) architecture, a Peripheral Component Interconnects (PCI) architecture, a PCI-Express architecture, a Personal Computer Memory Card International Association (PCMCIA) architecture, a Universal Serial Bus (USB) architecture, and so forth.

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There’s a reason SmartThings hasn’t turned on the Bluetooth radio in the V2 hub, two years after it was released.

This Amazon patent would cover a fix for that. But while the idea may have been obvious (Create distance between the Wi-Fi transmitter and the zigbee transmitter), the actual details of the working solution was not.

Credit where credit is due, and all that. :sunglasses:


It actually covers a lot more than that. Read the full patent. They’ve left the zigbee transmissions under the control of the logic board in the camera, but moved the entire zigbee coordinator (not just the antenna) far enough away And hooked it up in a very specific way in order to reduce interference.

At the integrated radio module circuit 400, when the electronic device {the camera} activates the output signal from the electronic device to the integrated radio module {the zigbee coordinator in the power cord module} circuit 400 from 1 to 0, certain functions may occur or be performed

This isn’t just a zigbee coordinator and a Wi-Fi router sharing the same power cord. It’s an integrated system driven by the multiprotocol hub, But with the zigbee component physically Located between the control device and the power supply cord.

It’s exactly the kind of thing that most people who don’t do hardware development don’t understand the difficulty of creating. But it’s definitely patent-worthy.


Thanks for the clarifications, @JDRoberts.

Now in an ideal and fair world, Samsung could and would license this Patent, if truly beneficial to SmartThings customers.

This is an interesting quote from you since you are an engineer. Isn’t the point of Journalism for non scientific or engineering Publications to simplify the information so it’s easily digestible to the masses?

There’s a difference between simplifying and oversimplifying. :wink: It’s a common challenge for reporters who are covering any technical topic.

Jacobsen has been good in the past about making corrections to articles when needed, so I imagine that eventually somebody from Amazon’s press office will give her more of the information that she needs to report the patent story accurately.

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Does anybody care about why this patent is not for zigbee over power cable? It doesn’t actually change the zigbee communications at all. What it covers is the way the CPU which controls the multiprotocol operations tells the zigbee coordinator what to do next. Not how the zigbee coordinator communicates to the zigbee end devices.

I had a whole long explanation ready with diagrams and everything, but then I realized probably the only people who would care can already tell from reading the patent application. :wink: