SmartThings Community

Z-wave scores huge UL win for security!

(Kurt Sanders) #2

Interesting UL endorsement for the security of the protocol… IMHO Z-Wave transmission distances are very limited. They might be acceptable in smaller homes, but certainly it is problematic in larger homes with walls between endpoint deployments… I still prefer and have wired endpoints and a dedicated alarm firmware for monitoring… When an entry or motion device reports an event, I know that the detection is 100% accurate, not a potential false positive or negative from an alarm based endpoint to the HA cloud and back.

I also find it interesting that the article states the following quote, since ST cloud rated false alarms have been frequently reported…not because of the protocol’s fidelity, but all the other points of failure.

“Operating in the 900 MHz band, Z-Wave battles much less traffic on the home network, so the technology can better distinguish between real and false alarms.”

Also note that UL did not certify Z-Wave for use in fire detection… Ummm…

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(Geko) #3

I have a Z-Wave network installed in a two-story house, with the hub on the lower floor and some sensors and switches on the upper floor at the opposite end of the house, with multiple walls between between them and the distance about 60 feet. I never had any communication issues with them.


That’s stated in a somewhat confusing way, but many of the false alarms that SmartThings community members have reported are due to exactly this. (While many more are not.)

If a zigbee device fails to get its check in messages through because of local interference, as many community members have experienced when their zigbee arrival sensor runs into local Wi-Fi noise, then a false Alarm (false positive) may occur because the system thinks the arrival sensor is “away” and then another activity triggers an intrusion alert.

You can see the same problem if you have an alarm set to trigger when a door is left open for longer than a specific time. If the door sensor was able to get the open message through, but then is unable to get the closed message through, You get the same kind of false positive alarm.

Both of these are false alarms caused by local interference. (Again, not the only reason why false positives can occur, but definitely one that has been reported by some community members.)

Intentional jamming, while very rare, could cause the same issues.

You also get missed alerts (false negatives) when there’s too much noise in the band. These are probably more common, but, as always, it just depends on the local set up. The motion sensor or contact sensor never gets its triggered signal through, so no alarm goes off.

Zigbee coordinators that have frequency hopping features are generally better at getting around these problems, but inexpensive devices, including the SmartThings hub, often do not support this feature.


(Kurt Sanders) #5

Agree to all above.

I think that some people reading this article may think that the “Z-Wave mesh network” is completely activated throughout heir home on all Z-Wave nodes. This, of course, is totally inaccurate, as only those devices that are A/C power-operated, act as Z-Wave signal repeaters, transmitting messages from node to node until it reaches its final destination.

Therefore, in medium to large homes or those homes with wall, glass, 900 Mhz devices and other Z-Wave distance limiting interferences, will need to potentially purchase some A/C powered Z-Wave switches to bring the Z-Wave signal to those areas in the home too far to reach from the original transmission control source (eg. ST Hub).

Security alarm systems are a unique HA beast, and when they activate to a false detection, everyone is annoyed and eventually the confidence of the security system is compromised and interpreted as, “Just another false alarm”. On the other hand, it is frustrating when a contact is opened, and the alarm system gleefully ignores it.

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(Kurt Sanders) #6

This might be true for your situation and Z-Wave signal transmission varies in home to home comparisons. For example, a wireless transmission signal may be able to magically transverse floors of a home because the signal can follow a multi-floor laundry shoot, or the open heating duct from the furnace in the basement to the attic. It is amazing when it works over a vertical distance that one would expect a dead zone, and when it fails when the same distance is horizontal through dry-wall or metal doors. SmartThings published a A Guide to Wireless Range & Repeaters technical document on these known limitations

Also some Z-Wave nodes can handle a weaker signal than others. For example, some Z-Wave locks, and some 5th generational outlets have known distance limitations, whereas, ST motion, contact, leak detection and Smart power outlet sensors can usually be placed further away from the hub or powered Z-Wave repeater.


ST branded devices are all zigbee, not Z wave. They actually have the shortest range but a somewhat more robust “try again” protocol than Zwave, which can help them.

Classic Z wave (fourth-generation) has a somewhat longer range than Zigbee.

Zwave plus (fifth generation) has a significantly longer range then zigbee or classic Z wave. I’ve never heard of any special distance issues related to fifth-generation after the initial pairing. Just the usual possible interference or degradation stuff. Quite the opposite: changing a classic device out for a zwave plus device usually significantly improves range.

It is true that during initial pairing A zwave plus device that supports advanced encryption may need to be very close to the hub to complete the security exchange, so that may be what you were thinking of. This is sometimes called “whisper distance.” But once the device has been successfully paired, that’s no longer an issue.

Zwave locks require beaming repeaters, but that’s not a distance issue. They have the same distance as any other device using their protocol, it’s just that the transmitting device has to support the beaming feature. They do have the same “whisper distance” issue, but again that’s only for the initial pairing.

Wi-Fi has the longest range of these four protocols, which is why some community members use the kumostat wireless tag sensors for some use cases where longer distance is required, like reaching a mailbox or outbuilding.

(Julie Jacobson) #8

Thanks for the cc. I’m enjoying reading the comments.

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We should probably also note that technically it’s not “on the home network” but rather “in the home environment.”

Even though they’re operating in the same band, the Wi-Fi network and the zigbee network are separate networks each with their own controllers. :sunglasses:

(Kurt Sanders) #10

I grant you that the SmartThings “Branded” items are all zigbee for now. But I just checked the SmartThings Store and found that it sells several Z-Wave items (Non Branded), like the GE Outdoor Light Plug-and-Control Power Outlet, First Alert Smoke Detector and Carbon Monoxide Alarm, GE In-Wall Outlet (Duplex Receptacle), etc… I’m guessing that the typical SmartThings user will not decide on their next home automation purchase based on the protocol, but will purchase based on their functionality requirements.

I not sure how the “try again zigbee protocol” with a shorter distance than Z-Wave will compare to a stronger Z-Wave signal when it comes to the complexities of both on signal fidelity through typical household problem areas or competing frequency devices. I guess that will be the ongoing debate between having both protocols in some devices, like the Iris power outlet and many HA hubs.

In my residential environment, I have tried the Aeon Labs Aeotec Z-Wave Smart Switch 6, Gen5 unit and quickly returned it when it did not connect over a typical distance that my other classic Z-Wave nodes had. I know that this should not be the case, but ACTUAL testing in residential house proved the disappointing results. Other users of this similar 5th gen unit also reported similar range issues in Gen5 (Z-Wave Plus) Range Issues

In my situation, I was able to pair the 5th generation “beaming repeater” device in “security mode” when I placed it close to the ST hub, but when it was moved to the final location not more than 30’ from the hub (walls, hallways, etc) and 20’ from the Z-Wave lock (a wall and a metal door), it would not assist the Z-Wave lock in our garage obtain a working signal. This is still an ongoing issue with trying to get a workable signal to our garage which is the furthest distance from the hub on the same floor.

My point in this thread, is that the Z-Wave UL certification for Z-Wave enabled alarm systems {and not fire detection}, will not alleviate the problematic issues that users may encounter when trying to deploy Z-Wave enabled devices some distance from their Z-Wave mesh network in typical houses and remote areas like a garage or third story. I have a “wired” alarm system that reports to SmartThings REST and distance is not an issue nor false alarms based on signal fidelity or strength.


Garages are always problematic. Typically lots of concrete and metal, sometimes additional insulation in the walls, just a mess. A lot of people end up drilling a hole and putting a device on each side of it just to get signal through into the garage.

Like you, I use a separate security system. I’ve had it for about 10 years, we’ve only had two false alarms in that time, and it’s been very reliable. But I do pay ian additional monthly fee for it, and I know a lot of people are trying to avoid that. Really my only complaint about it is that I feel like I pay a little more than the value I receive, but that’s pretty much what everybody feels. :sunglasses:

(Kurt Sanders) #12

I think we are talking close semantics here… for example, the SmartThings “A Guide to Wireless Range & Repeaters” - mentions home networks several times…


The repeater article uses “networks” correctly. :heart_eyes:

Old engineer joke:

“Semantics” to an English major are “specifications” to an engineering major. And getting the specifications wrong can kill people.

The point is the original article talks about “traffic” on the “home network.” The repeater article talks about “noise” from one network interfering with another.

Wi-Fi messages are not “traffic” on the zigbee network. They are “noise” in the environment where one network is affecting another.

It makes a difference when trying to solve the problem, because you would solve a high traffic problem differently than a noise problem. :sunglasses:

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(Kurt Sanders) #14

@JDRoberts: Agree with you on the garage…

The maddening thing in our home is that the SmartThings branded {Zigbee} open/close contact sensor works perfectly on the same outdoor garage door that the Z-Wave enabled lock cannot and I did not need a zigbee repeater for the contact to function.

I am still seeking a means to get the Z-Wave lock to work out there and hence my purchase of the Aeon Labs Aeotec Z-Wave Smart Switch 6, Gen5 which was a secure “beaming repeater” unit which proved to not work when placed half way between the hub and the lock on the same floor.

As far as problem solving, whether it is noise interference, wall/glass/metal or other, it is maddening when devices cannot operate at a range that is in the defined specification. Of course, I have Z-Wave reported as 30-150’.


Probably an obvious question, but did you run a successful Zwave repair after all the devices were in their permanent locations?

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(Kurt Sanders) #16

Many times… watched it on the IDE, brought the lock into the house, it worked, took it outside, inoperable, ran network repair again… ugh!

What I would love to see is a powerline type device that can package and carry the Z-Wave protocol over the home wiring…


Yeah, it sounds like “local conditions.” Garages are always a bear. :rage: Have you considered trying a Zigbee lock?

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(Kurt Sanders) #18

@JDRoberts: I could go that route with a new zigbee lock :joy:, but I have over $150 invested the Z-Wave lock I have now and I already have a working Z-Wave lock on the front of the house. It was too late to return the lock where I purchased it since I thought I could enhance my Z-Wave network to the garage with the Aeon Labs Aeotec Z-Wave Smart Switch 6, Gen5. Luckily, I was able to return that device… but I still have the college attitude to find a way to get signal out there.

I expect that some creative networking company will invent a Z-Wave Powerline wired/wireless repeater device for the home and they will sell like hot cakes…


For a number of technical reasons, that’s not going to happen, unfortunately.

There are things that you can do to try to reduce the barriers.

First, if you have a light fixture in the ceiling, put A zwave lightbulb in it. That’s not going to give you the beaming that you need to get to the lock, but it may let Zwave signals travel the length of the garage. The most important thing is it’s up above the level of the automobiles and freezers and most of the other stuff in garages that can block signal.

Put a beaming mains-powered device very close to the lock. That will usually be a pocket socket, but it could be a wired receptacle or a light switch. Note that you can even use a pocket socket on an extension cord and it will still work as a repeater.

OK, those two things together should mean that if a Z wave signal can get into the garage, it can get to the lock. Now you just have to get it through the wall.

Getting signal into the garage

  1. weather strip Some people just shave down one side of the door from the garage into the house, put regular rubber weatherstripping on it, and the signal can get through the weatherstripping where it couldn’t get through the door. You may need to put another Z wave device on the interior of the house fairly close to that door, but usually there’s a good place for those if you don’t already have one. Again, pocket socket, wired receptacle, relay, or light switch. This is probably the easiest solution, but because it requires modifying the existing door a lot of people don’t want to do it.

  2. Or add a repeater high up on the shared interior wall. Another alternative for some people is to plug an extension cord into an existing receptacle that is on the wall shared with the interior of the house, run that extension cord up the wall just about to the ceiling, and plug in a pocket socket there.

With this method you’re hoping that the Z wave signal can get through the wall at exactly that spot to that pocket socket, which will then repeat it to the lightbulb in the ceiling, which will then repeat it to the beaming repeater near the lock, which will then repeat it to the lock.

To find a good place to put it, take a battery powered Z wave sensor and hold it against the shared interior wall until you find a place where its signal gets through. You may have to try several places depending on what’s inside the wall. For example, a water pipe will probably block the signal. Then once you found a place, you can put the pocket socket there.

But there’s a problem here, which is another reason why Zigbee is sometimes a better answer.

Did you notice that we took three hops just to get across the garage to the door lock? First pocket socket to lightbulb to beaming repeater to lock. Zwave has a maximum of four Hops for any one message, which means it has to be the hub itself that is talking to that pocket socket on The shared interior wall.

Zigbee allows for more hops, which is why you often find zigbee devices working in places where Zwave devices don’t, just because you had to use a couple of hops to get around physical obstacles.

But maybe you don’t need the lightbulb. If you don’t have shelves or other things hanging on the walls, you might be able to skip using the lightbulb if you have both repeaters (the one on the shared interior wall and the beaming one near the lock) with clear line of sight to each other. You might not even need an extension cord with the one on the shared interior wall if there’s a wire receptacle on that wall with clear line of sight to the beaming repeater. (As I mentioned, garages are a bear.)

The problem is that most garages do have stuff along the walls. Or the receptacle on the shared interior wall is far enough over that there’s no clear line of sight to the beaming repeater. But if you can make it, work go for it.

Also remember in all cases that if you pair these devices right next to the hub, you need to put them in their permanent locations, then run a zwave repair, and then wait until the next day to actually test. It takes time for the address table updates to propagate after The zwave repair utility completes.

In your case we have to use up an extra hop because of the beaming repeater required. If the end device wasn’t a zwave lock, we might not need the extra repeater close to the lock, which would save us both money and a hop. But because it’s a lock and Zwave lightbulbs don’t typically support beaming, we need that extra device. Because probably the pocket socket on the shared interior wall will be too far away from the lock.

And we had to use three devices, which added together will probably cost almost as much is the zigbee lock.

( by the way, some lock manufacturers have interchangeable modules so that you can just take out the existing Z wave module and put in their Zigbee module. This saves you a lot of money because you’re not buying a whole new lock. You might check with your lock manufacturer to see if that’s an option For your model.)

  1. or reach the lock from outside the house and skip the garage interior altogether This is often a great option for Zigbee locks. You just put a $15 ZHA lightbulb ( directly connected to the ST hub) on the outside of the house. bounce the signal out the window to the bulb, then from the bulb to the lock.

But with a Z wave lock we run into that beaming requirement again. You may still be able to use it with an outdoor power receptacle that supports beaming, but placement can get trickier. Still, this is often an easier path than trying to get through the garage.

So those are just some additional things to try. Remember the four hop maximum, though, that trips up a lot of Zwave implementations.

I’m not sure what does Zigbee hop maximum is for smartthings (it can vary by controller), maybe @slagle can find out. :sunglasses:

(Geko) #20

Have you tried Z-Wave Extender? Amazon reviews say it works with Schlage door locks.

If you’re having Z-Wave communication issues at distances shorter than 50 feet, I suspect that Z-Wave radio in your hub may be busted.

(Kurt Sanders) #21

Thanks @geko… we think alike. When I returned the non functioning Aeon Labs Aeotec Z-Wave Smart Switch 6, Gen5 to Amazon, I purchased this exact Z-Wave repeater and installed it in our kitchen which is attached to our garage.

After a z-wave repair, which optimized the Z-Wave mesh network, the outside garage door with the Z-Wave lock was working only about 50% of the time but only when the kitchen garage door was open. In our home, we have a door leading to the garage, and our garage has both a garage door and car doors. The Z-Wave lock is located on the garage door which is about 15’ outside the kitchen door.

So it appears that I {might} need {yet} another Z-Wave repeater either closer to the kitchen garage door or on the other side of the kitchen door, in order to get a hop into the garage where the Z-Wave lock is installed.

My problem is “How many Z-Wave repeaters does one need to get a decent signal into the garage to operate a $150 Z-Wave enabled lock?” Each repeater of the above type ONLY functions as a Z-Wave repeater and has no other function.

Update: I recently purchased an IRIS L-3250 power outlet from Lowes that also operates as both zigbee and Z-Wave repeater for $35. I plugged that device into the outside garage A/C socket, paired it to have operate as a power outlet, Z-Wave repeater and zigbee repeater. But still no response from the Z-Wave lock. I take the Z-Wave lock inside the house and it functions as expected! Reinstall it outside in the garage, no response.

Now I see why my white hair is disappearing!