Dean Roddey
Senior Member
Is it 250Kb/s? I'd read 192Kb/s? 250 is better, so I wouldn't complain, but I'd just read otherwise.
Zigbee Devices finally coming 2006 Q1
- Thread starter Tombo
- Start date
ChrisWalker
Active Member
I think that there's quite a bit of mis-information still about Z-Wave (which I think is just misunderstanding--nobody's at fault here); I'll try to clear up just a _few_ of the points here:
Z-Wave runs at 9.6kbps (emulation and 1st-gen chips) or 40kbps (2nd-gen chips). Both of those are awesome for home control applications. The former is perfect for turning lights on and off, checking on garage door status, etc. The latter is perfect for chatter on the network, such as large live status updates.
Depending on design considerations, either mode can be used (based on which chip the OEM selects)--and then the network automatically uses the most appropriate speed and/or path, depending on what it's doing. It's very intelligent. Here's a bit more info, from a few months back: http://www.digitalconnectmag.com/technolog...leID=171200131)
Also, network traffic by default is very, very low, and is designed to be a good RF neighbor.
I think a lot of the "Zigbee vs. Z-Wave" topics that come up are due to the fact that most people don't understand what Z-Wave can really do. There's a lot there, and some of the new products coming to market use some of the cool features. For instance, most people thought that if a device failed in a Z-Wave network, the user had to "burn the network down and start over." But with the release of our Z-Wave PC SDK and the beta program for ThinkEssentials, people know that the opposite is true. The same goes for a lot of things, but it's up to the manufacturers to take advantage of the features.
You'll see us continue to take advantage of more and more of Z-Wave's power this next year. I sincerely hope that the power in these $1 to $3 chips becomes more and more apparent. Certainly some of the world's most established home hardware companies have noticed, and are releasing products based on them.
Chris
ZigBee runs at 20kbps (European), 40kbps (900MHz US), or 250kbps (2.4GHz) according to this article (which also stated that Zigbee devices were coming in Q2 2004): http://twice.com/index.asp?layout=articleP...cleID=CA411310.rocco said:
Z-Wave runs at 9.6kbps (emulation and 1st-gen chips) or 40kbps (2nd-gen chips). Both of those are awesome for home control applications. The former is perfect for turning lights on and off, checking on garage door status, etc. The latter is perfect for chatter on the network, such as large live status updates.
Depending on design considerations, either mode can be used (based on which chip the OEM selects)--and then the network automatically uses the most appropriate speed and/or path, depending on what it's doing. It's very intelligent. Here's a bit more info, from a few months back: http://www.digitalconnectmag.com/technolog...leID=171200131)
Self-building networks are nice for isolated applications. When you start getting into high-density residential buildings, you don't necessarily want networks to self-organize. Additionally, with Z-Wave it is possible to pre-program a batch of devices as a network before they ship, is possible to build a self-organizing Z-Wave network within single-vendor solutions (at which point the user could add other-vendor devices in the standard way), and much, much more.rocco said:
Portable Z-Wave devices may be moved around the network freely; if you move "static/stationary" devices around, either the user or software can take care of that transparently as well.rocco said:
With Z-Wave, you don't need a single point of failure (access point) to have portable devices in the system. Additionally, no single point of failure will bring down a Z-Wave system.rocco said:
Some of the Z-Wave chips have encryption built into them. And some Z-Wave manufacturers are building products with encryption and/or authentication built in.rocco said:
Multiple Z-Wave networks can also co-exist in the same space.rocco said:
Also, network traffic by default is very, very low, and is designed to be a good RF neighbor.
I think a lot of the "Zigbee vs. Z-Wave" topics that come up are due to the fact that most people don't understand what Z-Wave can really do. There's a lot there, and some of the new products coming to market use some of the cool features. For instance, most people thought that if a device failed in a Z-Wave network, the user had to "burn the network down and start over." But with the release of our Z-Wave PC SDK and the beta program for ThinkEssentials, people know that the opposite is true. The same goes for a lot of things, but it's up to the manufacturers to take advantage of the features.
You'll see us continue to take advantage of more and more of Z-Wave's power this next year. I sincerely hope that the power in these $1 to $3 chips becomes more and more apparent. Certainly some of the world's most established home hardware companies have noticed, and are releasing products based on them.
Chris
ChrisWalker
Active Member
P.S.
According to this article, the 40kbps and 20kbps speeds are "burst rates":
http://www.sensorsmag.com/articles/0603/14/main.shtml
Also, here's an example of a Zigbee device that just does 20kbps/40kbps:
http://www.atmel.com/dyn/products/devices.asp?family_id=676
And of course, it's important to understand that the network speed of any of these networks is not analogous to raw throughput. You have protocol overhead, etc. In the end, it's up to the embedded application developer to decide what works for them, but it's not common for 40kbps to not be enough bandwidth for home control types of applications. At some point, devices which need more bandwidth will start using things like mesh-networked WiFi.
Chris
According to this article, the 40kbps and 20kbps speeds are "burst rates":
http://www.sensorsmag.com/articles/0603/14/main.shtml
Also, here's an example of a Zigbee device that just does 20kbps/40kbps:
http://www.atmel.com/dyn/products/devices.asp?family_id=676
And of course, it's important to understand that the network speed of any of these networks is not analogous to raw throughput. You have protocol overhead, etc. In the end, it's up to the embedded application developer to decide what works for them, but it's not common for 40kbps to not be enough bandwidth for home control types of applications. At some point, devices which need more bandwidth will start using things like mesh-networked WiFi.
Chris
rocco
Active Member
Actually, I think fault lies with ZenSys, for trying to keep the ZWave protocol so secret.ChrisWalker said:
As an example, I have talked with ZenSys a number of times about pitching ZWave to potential clients, and this is the first I have heard of the 40,000 bit/second capability. One client picked ZigBee over ZWave simply because they could not evaluate the ZWave specification. ZenSys was very quick and thorough in answering specific questions, but that is not enough when you are selecting a technology to invest in.
I have read the specifications for ZigBee, UPB and Insteon, and know all of the variations of X10, but I have to admit that I know little about ZWave. And that is not for the lack of trying. I can't recommend ZWave to a client if I don't fully understand it's capabilities. So in effect, ZenSys's secrecy is preventing it from being adapted in some applications.
Some ZigBee clarifications:
The 2.4 GHz, 250Kbps version of ZigBee (Universal ZigBee) is what almost all manufacturers are adapting. 20Kbps (European ZigBee) and 40Kbps (US ZigBee), as far as I know, are only being implemented in remote sensors, where 10 year battery life is possible (but a potentially BIG market).
I'm not sure that's true. Self organizing does not mean your network will join with your neighbor's, and conspire against you. What it does mean is that your network can recognize when your cell phone comes home, and turn up the thermostat for it. Or your big-screen TV can display the pictures in your mom's digital camera. Or your water meter can send your usage to your water company each day, relayed through the other water meters in the city (this is currently being implemented in Korea).
But the burst rate is also the continuous rate when all time-slots are used. A device may transmit at the "burst" rate for the time-slot it has been granted, but as soon as its time-slot is over, another device might start transferring. If the network needs to utilize all time-slots, the burst rate becomes the continuous rate. If a device requires a certain amount of bandwidth, its coordinator can pre-allocate time-slots to guarantee the device the needed bandwidth.
Keep in mind that these technical differences does not mean that I think ZigBee is better than ZWave in the home automation market. On the contrary, I don't think the added complexity of ZigBee is necessary, and could well be a hindrance, in the areas where we now see ZWave. I may be developing with ZigBee, but it could have been ZWave if I was able to afford the ZWave developers kit.
ChrisWalker
Active Member
Rocco:
I'm very impressed by your knowledge of various protocols.
2 quick questions:
1. If 20kbps/40kbps Zigbee devices are running at 900MHz, how do they talk to the "majority" 2.4GHz devices?
2. I haven't heard of any companies developing around Zigbee because it was less expensive than the Z-Wave devkit. Generally, the assumption has been that Zigbee certification will cost more in and of itself than the Zensys hardware devkit. Do you know what it's going to cost you to get your product certified so that you can sell it? Or is this more a hobby?
As far as self-organizing goes, you're right--we are talking about two things (at once, and separately) here. As far as auto-detecting that my cell phone just made it home, that would be cool. That would also be possible with Z-Wave of course, but it would not happen automatically. But then again, that reduction in network traffic is probably a good thing for general home automation application.
For sensor applications, Zigbee may have very well found itself a market. Actually, that's what it was designed for in the first place (if I remember correctly). I think that Zigbee (or, more particularly 802.15.4) found a home in home automation only because there were no other really good solutions. But as the market landscape has changed, other options have emerged (and shipped, and are now in 2nd-, 3rd-, and 4th-generations).
This site does seem like it's becoming a good place for general Z-Wave knowledge.
Chris
I'm very impressed by your knowledge of various protocols.
2 quick questions:
1. If 20kbps/40kbps Zigbee devices are running at 900MHz, how do they talk to the "majority" 2.4GHz devices?
2. I haven't heard of any companies developing around Zigbee because it was less expensive than the Z-Wave devkit. Generally, the assumption has been that Zigbee certification will cost more in and of itself than the Zensys hardware devkit. Do you know what it's going to cost you to get your product certified so that you can sell it? Or is this more a hobby?
As far as self-organizing goes, you're right--we are talking about two things (at once, and separately) here. As far as auto-detecting that my cell phone just made it home, that would be cool. That would also be possible with Z-Wave of course, but it would not happen automatically. But then again, that reduction in network traffic is probably a good thing for general home automation application.
For sensor applications, Zigbee may have very well found itself a market. Actually, that's what it was designed for in the first place (if I remember correctly). I think that Zigbee (or, more particularly 802.15.4) found a home in home automation only because there were no other really good solutions. But as the market landscape has changed, other options have emerged (and shipped, and are now in 2nd-, 3rd-, and 4th-generations).
This site does seem like it's becoming a good place for general Z-Wave knowledge.
Chris
Rocco,
I agree with you on complexity. Zigbee might be more complex but that does not necessarily make it better for all applications. That complexity always puts a burden on the device and sometimes its not needed. As far as bandwidth, it would be nice to have a little more bandwidth than Zwave's 9600. Zwave works fairly well but with a number of devices and a couple hops latency goes above 1 second for current devices.
If all we need is high speed we would be using wireless ethernet. The main purpose of either of these protocols is low power (sensors with 5 to 10 years life open up a huge market ) with low cost (throw it away when done) . I did not intend to make this a which is better argument. I will use both myself because Zwave is here and Zigbee is almost here.
I do agree with offering cheap toolkits (got one free) and a open spec for Zigbee. When you want to take your product to market you could have it done and then pony up the money to certify it. Also, it is easier to know what the features are when things are more open. Thanks Chris for more ZWave info.
Tom
I agree with you on complexity. Zigbee might be more complex but that does not necessarily make it better for all applications. That complexity always puts a burden on the device and sometimes its not needed. As far as bandwidth, it would be nice to have a little more bandwidth than Zwave's 9600. Zwave works fairly well but with a number of devices and a couple hops latency goes above 1 second for current devices.
If all we need is high speed we would be using wireless ethernet. The main purpose of either of these protocols is low power (sensors with 5 to 10 years life open up a huge market ) with low cost (throw it away when done) . I did not intend to make this a which is better argument. I will use both myself because Zwave is here and Zigbee is almost here.
I do agree with offering cheap toolkits (got one free) and a open spec for Zigbee. When you want to take your product to market you could have it done and then pony up the money to certify it. Also, it is easier to know what the features are when things are more open. Thanks Chris for more ZWave info.
Tom
Dean Roddey
Senior Member
Zen-Sys, IMHO, completely shot themselves in the foot by putting up too high barriers for support, and for being very uncaring of integration into external automation systems. If they'd have pushed their SDK on every automation system or device vendor out there, and created their own (standardized and high quality) PC interface, and acted like a company like Elk does, they'd be so dominant now that we probaby wouldn't be having this conversation. They just have a lot to learn about market development relative to other companies.
To me, Zen-Sys is like the girl who says she might go out with you, if you buy her a fur coat and lose some weight, while a company like Elk is the girl who thinks you are cute and wants to party. Which one of those girls are you likely to end up spending the most time with?
To me, Zen-Sys is like the girl who says she might go out with you, if you buy her a fur coat and lose some weight, while a company like Elk is the girl who thinks you are cute and wants to party. Which one of those girls are you likely to end up spending the most time with?
BraveSirRobbin
Moderator
The one with the biggest....Dean Roddey said:
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. allowable Home Automation budget!
Seriously though Dean brings up some good points. I'm going to CES this year and will try to visit these vendors as well! I would like to hear their thoughts on these topics in person (if all are attending the show this year).
ChrisWalker
Active Member
Hi Tom,Tombo said:
You're very right. Microsoft created UPnP, but quickly realized that it was a really good "bridging" protocol--but that it was not really feasable at this time to put a web server, XML parser, etc. inside of every light switch and device.
Again, it's also important to note that Z-Wave is now 40kbps, with seamless backwards compatibility for 9.6kbps. Even with 4 hops, we have not seen 1 second latency in a Z-Wave network (unless, of course, it has bad routes--in which case it may take a few moments to figure out which ones are good). Your response time reports on the SDK forums indicated that you're seeing 100-200ms response times (for full stateless request/response operations), with the exception of one device which is for some reason quite slow in responding. Have you seen 1s response times?
We have tested hundreds of Z-Wave nodes in a single system, and have not seen major issues. But then again, we're also using smart controllers
Chris
Dean Roddey
Senior Member
UPnP, to me, is really only practical for PC-like systems, and even there it might be more work and overhead than some companies really want to get into.
rocco
Active Member
They don't, at least not directly. A bridge would work, I guess. I know of no-one designing for either 20kbps or 40kbps ZigBee. One security device I'm developing will last 6 years on it's battery, despite the fact that I'm using 250,000 bps ZigBee. I personally feel the slower variants are a waste of time.
To join the ZigBee Alliance at the least expensive level will cost $3500. The actual testing fees are set by the individual testing lab, either National Technical Systems (NTS) or TUV Rheinland. I have no idea yet what they will charge, but using a certified platform makes it cheaper than if you rolled-your-own platform. Then, to get the logo for the first device, it will cost $1000. Logos for additional devices cost $500.
Like Tombo, I received a development kit for free. The big difference between the cost of ZigBee and ZWave is simply WHEN you have to pony-up. With ZWave, you need to invest before you can start. With ZigBee, you don't need to invest in alliance membership or the logo until your product is done. This becomes especially important if you are not sure of the feasibility of your product, or if you're worried about missing a market window.
ChrisWalker
Active Member
Rocco,
That's not a bad way to do things, by the way. But I don't think it's a good way to approach the home control world.
You got your Zigbee developer kit for free? Wow. I didn't know that any of the chip companies were giving those away! Are they available for free, generally? If not, what is the standard price, and what does it come with? Did you need any compilers or hardware outside of the kit?
I may be missing something here, but according to the "benefits" page on the Zigbee.org website, a company has to be a "participant" to create Zigbee-logo products, at a cost of $9,500/yr:
http://www.zigbee.org/en/join/benefits.asp
And of course, it scares me that I can't find the testing fees of either NTS or TUV on the web. The Z-Wave certification (total for both verification and logo) fee is $750 USD. Z-Wave Alliance membership appears to be extremely low compared to Zigbee Alliance membership. I may be imagining things, but it seems much, much more expensive to be able to create Zigbee products--which is especially hard on the smaller companies.
I'm excited to see what security product you're building. Six years is a long battery life. I know that Z-Wave chips will run for ten years on a set of AAA (or is it AAAA?) batteries. But for systems with smaller numbers of devices, six years isn't bad at all.
Chris
More and more, it is seeming like 802.15.4 (not to be confused with Zigbee, whcih is the "application profiles" part built on top) was designed much like WiFi: multiple options (802.11a vs. 802.11b vs. 802.11g). Some work together, and some don't. And it's up to the consumer to figure out which ones do and which ones don't. Unfortunately, it's probably not going to be cost effective (any time soon) to create "multi-band" devices (like 802.11a/b/g cards). Once the devices are on the network, there's no guarantee that they'll work together (like in WiFi--it's just the networking layer), but if the various manufacturers want their applications (i.e. devices) to play with others, then they'll either use standards (like HTTP is over WiFi, and the Zigbee profiles could be) or create custom links (like Google Talk does).
That's not a bad way to do things, by the way. But I don't think it's a good way to approach the home control world.
You got your Zigbee developer kit for free? Wow. I didn't know that any of the chip companies were giving those away! Are they available for free, generally? If not, what is the standard price, and what does it come with? Did you need any compilers or hardware outside of the kit?
I may be missing something here, but according to the "benefits" page on the Zigbee.org website, a company has to be a "participant" to create Zigbee-logo products, at a cost of $9,500/yr:
http://www.zigbee.org/en/join/benefits.asp
And of course, it scares me that I can't find the testing fees of either NTS or TUV on the web. The Z-Wave certification (total for both verification and logo) fee is $750 USD. Z-Wave Alliance membership appears to be extremely low compared to Zigbee Alliance membership. I may be imagining things, but it seems much, much more expensive to be able to create Zigbee products--which is especially hard on the smaller companies.
I'm excited to see what security product you're building. Six years is a long battery life. I know that Z-Wave chips will run for ten years on a set of AAA (or is it AAAA?) batteries. But for systems with smaller numbers of devices, six years isn't bad at all.
Chris
rocco
Active Member
Hi, Chris:
The Freescale kit came with three nodes containing sensors and serial/USB ports, the stack library, and the development software (C++). The development software comes from Metrowerks, and truly sucks.
Remember that the ZWave alliance was created this year, after ZWave was defined. The ZigBee alliance was created years ago, as the very first step to defining ZigBee.
Luckily, they don't. This is where "Stack Profiles" come in. A light dimmer, for example, would have to conform to the "Home Control Profile". This profile specifies the required options, like the type of beacon, the routing table, neighbor table, discovery table and binding table sizes, and the security settings. If a light dimmer doesn't work with every other light dimmer, no logo.
I've been using Motorola (now Freescale) microcontrollers for 25 years, and my FAE knows the type of work I do, so they did not hesitate to give me one. If I had to pay for it, it would have been only $199. Microchip sells their low-end kit for the same price. Chipcon (prior to TI) had the most expensive kit, at about $5K. Freescale had a competition last year where they were giving away the same $199 development kits. As the competition for the chip-sets heats up, I expect to get more offers of discounted development kits.
The Freescale kit came with three nodes containing sensors and serial/USB ports, the stack library, and the development software (C++). The development software comes from Metrowerks, and truly sucks.
Yeah, this is confusing. Promoter and Participant memberships have the logo included. Adapter members have to pay the $1000 or $500 for each logo. If you are only going to do a couple of products, adapter is cheaper.
It scare the bejesus out of me, also. My clients pay for their testing, so I don't worry too much, but I have rights to those products as well, so I may have to pay for my own testing someday.
But they really are different. Promoter and Participant members help draft the specifications. They get to review and comment on the drafts of the specs, and they vote on the final specs.
Remember that the ZWave alliance was created this year, after ZWave was defined. The ZigBee alliance was created years ago, as the very first step to defining ZigBee.
I'm using a lithium coin-cell (100ma-hour) that is soldered onto the control board. The board is embedded in a portion of a dead-bolt. If the battery dies, you simply replace that portion of the deadbolt.
