Hop, skip and jump: Mesh network/topology mapping questions


#1

OK, I understand that the more robust the mesh network the better. I suppose I could plug a repeater into every outlet, but…
I remember reading that the maximum number of “jumps” between the hub and a device is 3. Is that correct? Having a ton of repeaters would be useless if number of jumps is limited to 3 or less.
Is there anyway to check/map network topology? e.g. send out a command and see which nodes it travels through. It would sure be a help understanding where “dead spots” are and where the network is on the fringe of working. It would also help me find the best placement for repeaters (e.g.which is better: shot through a frame house exterior wall or window with metal screen?)


#2

It depends on the protocol. Zwave has a lower number max than zigbee.

For zwave, one controller can handle about 230 nodes, up to 4 hops (not 3).

For zigbee, it depends on the addressing protocol, but networks with thousands of nodes and 20-30 hops are common in commercial sensor nets. For the zigbee home automation profile, which is what SmartThings Uses, it’s 15 hops into the hub and 15 hops out, so maximum of 30 for one message.

SmartThings unfortunately does not provide us with address table tools that I know of.

Also, remember that the whole point of mesh is that the routes may be different for different attempts. You can’t think of it like a tree topology.

To test placement, strip away everything but the repeater and one node, then just test signal strength for that node as you move the repeater around.


(sidjohn1) #3

Depends on technology Zwave has a 4 hop max, zigbee is 20. Just about any plug-in or wire-in zwave/zigbee device will also repeat the signal, no dedicated repeater is necessary. IDK if there is a way to view the network but there are ways to update the routes. Zigbee is simple, reboot the device. It will update its routes on power up. Zwave requires a “Repair Z-Wave network” this can be done on https://graph.api.smartthings.com > My hubs > View utilities. I would recommend repairing your zwave network after adding a new zwave device.
For zwave distances and materials check out page 4 http://ecx.images-amazon.com/images/I/71W948wFilS.pdf
Metal in general is normally no good for anything wireless and a metal screen is 1\6 of a faraday cage.


#4

As @sidjohn1 mentions, one of the huge advantages of mesh is that many different devices can act as repeaters while also performing their primary function. Light switches, power receptacles, many relays, even some light bulbs. It’s rare to buy a device that is only a repeater, although may deploy a signal amplifier. But even that is pretty rare since you don’t need to talk to the hub, just the next hop. (Again, not a star or tree topology. Short low power hops work fine.) pretty much any mains powered device will act as a repeater with the exception of smoke alarms and similar devices, where the manufacturer wants to be sure a primary alert isn’t missed because the device is busy repeating a lower priority message.

Both zwave plus and zigbee 3 (next generations) are promising longer range at lower power draw. 4 hops should be enough to cover most houses.

See:


#5

Thanks for advice. Am trying Repair Z-wave network…
Clicked it Got:
{“message”:“Z-Wave network repair initiated - Click to view progress”}

so far nothing more…

Clicked window (in Chrome)… nothing more

Is that normal??


(sidjohn1) #6

yep, completely normal… it will run for ~ 15min and unless there is an error you won’t see anything till its done. I think you can also see some stuff if you open live logging as well.


#7

How many zwave devices do you have? And how many are battery powered?


#8

Yes i finally cam back with “rebuild complete” - had me worried.

I’ve got a couple dozen switches, dimmers and outlet fixtures.
Only one battery operate device (garage door sensor).
The house works fine, but I’ve got a pool and workshop-shed a little distance from the house. Due to the way the house was originally wired, all of the switches in the house (all ST now) have obscured line-of-sight to the pool or workshop, so it is somewhat difficult getting reliable signal there. I picked up a couple of Aeon repeaters that I’m going to try to deploy to help with the jump to the pool/shed.


#9

How do you “test signal strength”? I recall seeing a device signal strength way way back but don’t recall where.


(ng) #10

Is there a way to see this?