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 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:Raw Bandwidth:
ZWave is 9,600 bits/second.
ZigBee is 250,000 bits/second.
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:You don't "build" the network, as in ZWave; It builds itself.
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:Nodes can be moved around freely.
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:No single or multiple failure will bring down the network.
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:128 bit encryption, with either network-wide keys, or private keys between two nodes.
Multiple Z-Wave networks can also co-exist in the same space.rocco said:Multiple ZigBee networks can co-exist in the same space without interference.
Actually, I think fault lies with ZenSys, for trying to keep the ZWave protocol so secret.ChrisWalker said: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'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).When you start getting into high-density residential buildings, you don't necessarily want networks to self-organize.
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.According to this article, the 40Kbps and 20Kbps speeds are "burst rates"
The one with the biggest....Dean Roddey said:Which one of those girls are you likely to end up spending the most time with?
Hi Tom,Tombo said: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.
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.
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.1. If 20kbps/40kbps ZigBee devices are running at 900MHz, how do they talk to the "majority" 2.4GHz devices?
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.Do you know what it's going to cost you to get your product certified so that you can sell it?
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).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.
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.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.
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.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?
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.. . . 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
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.And of course, it scares me that I can't find the testing fees of either NTS or TUV on the web.
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.Z-Wave Alliance membership appears to be extremely low compared to ZigBee Alliance membership.
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.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.
Rocco,rocco said: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.