Competing wireless technologies for home automation

[ey143]

http://www.ubisys.de/en/smarthome/technology-comparison.html

Please take a look at the above in the above link. Is it true that zwave has no encryption? I was thinking of going for z-wave devices compared with other wireless protocols like zigbee. Should this concern me?

 

[bernardgreen]

no encryption? ~~~~~~ Should this concern me

Only if you are passing confidential or sensitive information over the wireless links.

The biggest concern is whether system can cope with channel blocking when no data, encrypted or not, can be sent from one item to another rendering the system in-operative.

As all systems have to use one of the very few licence exempt the chances of short term blocking will increase as more and more systems are sold. There is also the matter of jamming when someone uses a transmitter to intentionally block the channel for long periods of time. Such transmitters can be bought from various sources, it is not illegal to sell them but it is illegal to use them. Enforcing that is almost impossible.

One aspect of security / safety is the " accidental " operation of equipment by a command sent from equipment that is not part of the system but uses similar data formats and address ranges to identify its system components.

 

[dpm_dpmartin]

I have various devices in the house. It doesn't concern me at all whether they are, or are not, encrypted - my biggest concern is that the things I buy actually work (not always guaranteed in this totally compatible Z-wave world).

 

[ey143]

I have various devices in the house. It doesn't concern me at all whether they are, or are not, encrypted - my biggest concern is that the things I buy actually work (not always guaranteed in this totally compatible Z-wave world).

Please expand on the last few lines. Why are they not guaranteed to be compatible if they are the same wireless technology?

 

[dpm_dpmartin]

Because certain gadgets come out and say they adhere to the compatible specification that your controller supports, but they do not work... they might, eventually, when the controller manufacturer releases new firmware, or the device / gadget manufacturer does the same, or they bother to get together and actually do some testing... but don't hold your breath.

They are guaranteed to be compatible - logos showing and all that - but, sometimes, they're not.

 

[SimonH2]

Please expand on the last few lines. Why are they not guaranteed to be compatible if they are the same wireless technology?

Two reasons.

The first is that different implementors may "interpret" the standard differently - so you have bits of kit designed by different people, who both think they have done it properly, but for some reason they don't quite work together properly. Often, standard have enough "wiggle room" that both implementers could actually be correct

The second is that some vendors have a vested interest in not working with anything else. Thus you'll find stuff that is supposedly "some specified protocol" but the vendor has deliberately knobbled it so that you cannot use anyone else's kit with it. That's simply because the vendor wants you to buy only their own stuff.

There is a "turf war" on at the moment with several large vendors (Apple and Google come to mind, but there are several others) all vying to "own" the IoT market. There's a lot of money likely to be spend in the coming years - and they all want to "own" as much of it as they can.

Also, it's not just about the money from the sales of kit - there's also money to be made from "owning" the user. Hence the preponderance of kit designed to only work (properly or at all) without being connected to the internet - specifically the vendors servers where they can collect data about you (remember that with Google in particular, YOU are the product being sold).

 

[ey143]

Do you have actual examples of non interoperability between manufacturers on the same protocol though?

Unless I am confusing what you're saying about items like Samsung Smart Things which operate on the Zigbee protocol and requiring manufacturers to produce for their platform.

 

[dpm_dpmartin]

Of course, otherwise I'd not bring it up as an issue. Z-Wave, it can be a minefield.

 

[bernardgreen]

Read about the way devices are identifed by an address. Then consider that some manufactures will limit the range of address their equipment can use to prevent it being used with equipment from other manufacturers.

If equipment made by manufacturer A uses addresses 1 to 999 and rejects all other address and equipment made by manufacturer B uses addresses 1000 to 1999 and rejects all other address then the two different makes of equipment are not compatible as they cannot talk to each other. Third party equipment which has complete freedom of addresses can be programmed to communicate with equipment made by both A and B

 

[ey143]

Of course, otherwise I'd not bring it up as an issue. Z-Wave, it can be a minefield.

Why is z-wave a minefield? Surely that's the easiest of the lot given the level of interoperability.

 

[dpm_dpmartin]

Because products are released by various different companies that simply don't work with each other... as I've already said.

For example (1), I think this is what you are wanting, consider the Aotec 6-in-1 multi-sensor and the Vera Edge controller... upon release in the first half of 2015 they did not work with each other - you could not configure them properly, if you managed to hack it then it didn't display its readings reliably or often at all - each company blamed the other for something (not sure what) and promised that it would be resolved... in Aug 2015 I was told it was high priority, the sensor still does not work with the Z-Wave controller.

For example (2), consider the Somfy battery-powered blinds controller and the RFXtrx433E dongle working with the Vera Edge, yes, you can control your blinds, but the icon in the controller is not a window (or representation of blinds) but rather a light bulb. Vera released a new version of firmware where the blinds did actually have an icon of blinds, excellent, but that broke the USB functionality that is required by the RFXtrx433E dongle, which controls the blinds, so you could have them looking like blinds in your controller's admin. interface, but not actually have them going up and down. I had to have Vera Support provide me a down-level firmware to get my light bulbs icons back and the control of the blinds, I've not upgraded again.

Hope that helps.

 

[cjard]

Is it worth sticking with one manufacturer then? Is it even possible?

 

[SimonH2]

Of course, what every manufacturer wants is for you to stick with only their devices. As pointed out, for the larger manufacturers at least, "open and interoperable" is the last thing they want.
Now, whether one manufacturer provides the functions needed/wanted is another issue. If manufacturer 1 offers A,B, and C, and manufacturer 2 offers A, C, and D, and you want A, B, and D then you're stuffed unless you can get two makes of kit to talk to each other.

Now, in some fields, there is enough recognition that interoperability isn't optional - then manufacturers (or more likely protocol groups or trade groups) will get to together to hold interoperability lab sessions. The manufacturers come along with their kit, try it with other kit, and then figure out what doesn't work and how to fix it.
This only happens when it's something that the public just won't tolerate "issues" and having "non compatible" kit means getting a crap reputation and being locked out of the market - and it also requires that no single player has enough of the market to dictate things.
IoT isn't one of those fields - whether it gets to be one in the future, well your guess is as good as mine, but I suspect it's going to be driven by a small number of "big names" working on the "work by my rules or not at all" attitude to smaller manufacturers.

 

[dpm_dpmartin]

Is it worth sticking with one manufacturer then? Is it even possible?

I would say it's hardly possible with Z-Wave, not if you are interested in latest and greatest devices and features - these are going to be released by different companies on different schedules. In addition, some companies just don't play in certain spaces anyway, e.g. blinds. If you just want a set of simple on / off switches, perfectly possible.