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Re: Zigbee
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You're talking here specifically about a very broad-base kind of
application - broadcasting a time signal for all appliances in the
house to digest. A credible home networking standard should account
for the fact that some data is going to be sourced in a few places and
sunk in a lot of places, and furthermore that some appliances will
never have, or for cost reasons will not be able to have, good reasons
to communicate; they will be pure data sinks that merely need to
understand their environment without interacting with it
bidirectionally.

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The hand is faster than the eye :) But I basically agree with what you
say anyway.

HOWEVER! A car stereo is a special case, because it is scientifically
proved that a man's genital size is directly related to his vehicle's
capabilities, accessories and racing stripes. You can sell practically
anything into the automotive aftermarket, no matter how expensive or
ludicrous.

I'm talking about bread and butter appliances like coffee makers and
microwaves. There IS a market for custom luxurious devices of this
sort, but it's exceedingly small; I would say, not worth exploiting.
And the people who currently sell almost all the volume in this sector
are bulk shippers of Asian-made kitchen electronics. They do not have
the sexy high-end vibe that consumers of the luxury devices would
require.

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GPS? My $3.50 BOM cost is for receiver IC, all required passives, and
antenna, to receive that atomic clock off-air time signal. That's for
volumes that are somewhat smaller than microwave shipments. I've
assumed the product already contains a reasonably fast 8-bit micro
(which is a ~$1.10 cost in the same volumes, just in case the
microwave doesn't already have a fast enough brain).

The $6.75 Zigbee chip price you quoted requires probably another $3 in
passives and antennas.

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Yep. Do it every day at my day job, in fact, though in a much higher
frequency band. Actually, I can get a low-data-rate transceiver put
together for less than that, if you don't count the cost of the micro.
But I wouldn't ADD $10 to the cost of a $10 appliance by squeezing
this crap into it.

Re: Zigbee
On Friday, in article

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There LOTS of ways to do that simple task, if the companies could be
bothered.

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In most countries of the world there are Atomic clock radio signals as well
as:-

    1/   TV stations using teletext encoded time signal that
         displays on screen.
         Already used by a lot of VCR manufacturers to set clock
         and station ident for auto tuning.

    2/   Digital Radio and TV signals in UK contain time signal as well.

    3/   Digital RDS on analog RDS system has time within it.

    4/   GPS is a pretty accurate time signal.
 
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See above, if the manuafacturers were bothered they would use the existing
and mainly very cheap methods to do the same. Often the cost/benefit to
the *manufacturer* of increasing sales is non-existant.

Putting bloated communications in to wire up the house/office/etc.. is
way too costly to acheive any benefit.

Distributed Time Of Day is at mininum a single pair transmitting 'n' pulses
a second, to a short encoded data burst, with local oscillator to cover
for problems.

For MANY years schools and public buildings have often used synchronised
clocks on a common drive circuit to synchronise all the clocks in a building!
I even remember them from my school days, mumble, mumble, mumble years ago.

A lot of the railways in the UK used synchronised clocks on a station, with
local backup, referenced to MSF (Rugby Atomic Clock). Not that MSF is known
for 100% uptime! That transmitter has a wonderful history, and some of the
stories I have heard over the years about Rugby transmitter during WWII
were interesting.

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Thankfully.

--
Paul Carpenter          | snipped-for-privacy@pcserviceselectronics.co.uk
<http://www.pcserviceselectronics.co.uk/ PC Services
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Re: Zigbee
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Yes, those are all alternate methods of deriving the time of day, but
are they all cheaper to implement than, say, a local area power-line
carrier network?  Remember, only one device actually needs to get the
time independently, perhaps from one of the sources you mentioned.  The
others could get it from the device which has the most accurate time.  I
don't need a TV receiver, a digital radio, or a GPS receiver in my
coffee machine.

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"Too costly" and "bloated" both presume some particular implementation
(and a bad one at that).  I'm not advocating any particular
implementation; I'm simply pointing out that there *is* a potential
benefit to connecting appliances -- in your original post you seemed to
believe that the only reason to connect devices was "because we can."

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Sure, that sounds like the old IRIG-B standard.  This would meet my
definition of connecting appliances to meet this one particular purpose,
but do you think it's reasonable to use for connecting appliances?

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Was the gratuitous demeaning comment really necessary?

Ed


Re: Zigbee
On Saturday, in article
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...

You are forgetting a few things, but see more general comments on the end
as well.

   a) Most countries don't like data over power WITHOUT suitable blocking
      filters to stop your data interfering the power companies signalling
      and next door neighbours signalling etc..

   b) The coffee maker does not require accurate time keeping see later.

   c) Adding a connector (or power line data receiver) to a VERY cheap
      device adds cost, also adds cost to the documentation, testing
      validation to necesary standards etc..

   d) For a coffee maker it is overkill and unecessary where as time
      synchronisation is important for timer functions related to the
      outside world (i.e. VCR), so they use the time components in that
      medium to reduce cost.

   e) A distributed time signal as others have stated is a solution
      looking for a problem. The real time saver would not be setting
      of time by network but a simple means of daylight/standard time
      switchover. Even then that is a luxury market item as so many timers
      are in different markets (heating systems, clocks, appliances).

   f) making the potential for ALL users NOT to foul up the wiring of time
      network when cross connecting between ANY manufacturer at ANY distance
      around the home, is not simple. The cable will always be too short,
      too long or wrong connector or wrong protocol!

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The cost of putting an atomic clock receiver into EACH device that has
NO other means of receiveing time (i.e. VCR) would be cheaper than power
line carrier network.

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To manufacturers of microwaves/coffee machines just adding another connector
or power line receiver is bloated. To sort out support issues of what to do
if that time network does not exist, or a different time network exists,
cabling and associated issues adds to the product cost.
 
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It is "because we can", which is at the end.

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No only for SPECIAL circumstances that require it and the home does not!

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It was on reflection over harsh, but you were trying to get a solution
before determining the problem.

Let me put timekeeping in the house in perspective.

If you ask some one the time, what will they tell you? Most likely the
time to within 5 or 15 minute intervals, e.g. "five [minutes] to six",
"quarter past three". This is one of the reasons that people created even
TV listsings to that level of accuracy, for the public. Inside a broadcaster
the TV schedule may well be done to the second for adverts/trailers, programme
elements or the like.

Now we know the general public runs its life realistically to time in steps of
5 minutes.

Also if you were to wander around a house and look at all the timing devices
(clocks to heatings systems), you will find it most unlikely that any two
were showing the same time to same minute, some may well be run deliberately
ahead or deliberately behind 'real time' measurement. For example the
alarm clock set 10 or 15 minutes ahead of time, so soemone will get up, rather
than leave things to the last possible moment to get up in the morning.

Does the public's life go awry because of this? No because they are not
living their lives that rigidly, and are flexible.

Now consider the appliances they do NOT need to be synchronised to a time
standard, they need to measure elapsed time accurately. By this I mean if you
set your coffee maker to start at 6:25 AM, it does not matter if the time
standard ('actual time') is 6:20 to 6:35, all that matters is that it is
as near as possible 24 hours elapses between each time the coffee maker
registers 6:25AM. Will you always be up and ready to take the first cup
of coffee at exactly the same second (or even sub-second) every day? No of
course not we all do things to slightly variable time each morning and
things get in the way (longer in the bathroom etc..). As long as the vast
majority of times this means the coffee is ready each morning before you
enter the kitchen is all that matters, it may have been for 10 minutes
but so what.

Things that need to be synchronised to a time standard can be, such as
VCR so you record the programme at the time specified in the listing, which
is when they transmit the programme. Other such items might be a telephone
answering system (which can in UK get the time from the Caller ID data stream)
so that both ends are refering to the same 'actual time' that a message
was left.

The only possible problem that could do with a 'network' solution is the
daylight/standard time changeover with the ever increasing number of
timers in products. Most are getting so they do this themselves, VCRs from
TV signals, phone systems from Caller ID strings, clocks from atomic clocks
and the humble computer by software date calculations and interent time
servers.

The real appliances that could with an automatic clock are heating systems
as they often are the ones forgotten.

So networked appliances are generally not necessary and only will end up with
a USB situation where more and more will be put in the serving end, so if
the serving end fails ALL the other appliances will stop working! Why because
they can then make the 'client' end cheaper, so foregoing the timer function
but using the time signal to measure time. Then when your server fails
your microwave cannot time how long to cook and coffee filter does not come
on at the specified time, the VCR fails to record the programme you want.

--
Paul Carpenter          | snipped-for-privacy@pcserviceselectronics.co.uk
<http://www.pcserviceselectronics.co.uk/ PC Services
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Re: Zigbee


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If my coffee maker had a "back button" so I wouldn't have to press the "up
button" 23 times every fall, I would gladly pay the extra cost (up to $0.10
US).

I may be kind of a funny old fart engineer, but I am surrounded by
electronic devices that could be vastly improved with a little better
engineering and a little bit smarter software. A network might be cool too,
but first choice would be the extra button.

-Hershel Roberson

Re: Zigbee

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Well thought out control panels are getting rarer in my experience. Too many
multi-level menus, often for options not on this model.

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--
Paul Carpenter          | snipped-for-privacy@pcserviceselectronics.co.uk
<http://www.pcserviceselectronics.co.uk/ PC Services
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Re: Zigbee
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Maybe I'm just extraordinarily lazy, Hershel, (and there is some
evidence for this!) but I'd rather have a no-button interface that
didn't require me to fiddle with it at all.  A Model T Ford used to have
a spark advance knob.  I don't think that the loss of it was widely mourned.

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That's because a hundred lines of code is cheaper than the $0.10 button,
and if everything is software you don't have to think things out because
"you can always patch it later."

Ed


Re: Zigbee

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Necessary, no, but I can see many possible uses for networking
appliances and other electronic/electric devices in my home.

1. Fault detection - I'd like to know my deep freeze in the basement
stopped working the minute it stopped, not a day later when all my
stuff thawed out.  I'd like to know if my dryer was running too hot, or
water heater pressure was too high.

2. Cycle completion notification - My laundry equipment is in the
basement.  A notification that the washer was finished to remind me to
move the clothes to the dryer would be nice.  Likewise, having my oven
or microwave let me know when the cooking time was finished would be
nice as well.

3. Usage data - What shows were watched on the TV?  What did my kids
(if I had any) watch while I was gone shopping?  Who called me last
Tuesday and at what time, or who made that long distance call to Buenos
Ares?  When was my doorbell last pushed?  How much electricity is my
water heater/refridgerator/dryer/etc. using (so I can look a more
efficient model)?  What's my water usage for the month?

4. User Interfaces - Some devices have cruddy built in user interfaces.
How many people use their oven's programmable cooking features (for
instance, for putting something it when you leave for work and having
it done when you get home)?  I'm not going to go to my PC to program my
coffee maker, but I might do that for my oven.  More practical would be
my thermostat, to regulate my heating and cooling system according to
my usage patterns.  Typical programmable thermostats have horrid user
interfaces.  But a web server type interface could be a rich as needed.

5. Others - Rainfall for my area is up (or down) this week, so adjust
my sprinkler system accordingly.  The garage door has been open for ten
minutes (oops, I forgot to close it).

None of this is necessary.  Ice makers and water dispensers on a
refridgerator aren't necessary either, but people will pay for the
convenience of them.


Re: Zigbee
snipped-for-privacy@comcast.net writes:
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Be careful what you ask for -- you might get it.

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presuming it's in a condition to tell you...

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when was the last time someone's water heater pressure
got too high?

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and you're going to be overwhelmed with "data".  Now,
what are you going to do with it?

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certainly the UIs are not great.  Do you want the
manufacturers to spend 10 times the cost of the
basic device to add a nice UI?

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Oops, I was working in the garage and the $#%&*%&^ computer
shut the door on me!

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Not everyone...

Re: Zigbee
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If I am actively monitoring it, and it no longer responds, I certainly
should be alerted about it, just like I get alerted if my CPU fan quits
turning.

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In my 20 years out on my own, I've had three pressure valves blow,
flooding the basement.

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I am not necessarily going to keep it all, only what I am interested
in.  And what I am interested in may be completely different than the
next guy.  In general, I would likely only keep or be notified of
out-of-norm data.

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Nope, but a buck or three wouldn't bother me.

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Didn't say anything about closing it.  More like the door ajar light on
the car dash, without the annoying bong sound.

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Of course not, just as not everyone gets icemakers or surround sound.


Re: Zigbee

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And what good is a remote monitoring of that going to do you?  If
you're actually off site, by the time you get there to do something
about it, it's quite certainly too late.

The morale: instead of monitoring crappy parts that are likely to
break, it may just be a better idea to use a quality part.

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You're neglecting the central dogma of privacy protection: all data,
once generated, will eventually be used by *someone* --- thus, the
only reliable way to protect your privacy from being invaded is to not
even acquire those data.

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You would.  But what about the burglar investigating your habits to
find out when best to come and steal it all?  Or your nosey insurance
company detective?

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You're not getting the point: a buck or three per device may very well
*be* 10 times the cost of the basic device.

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Yeah, and guess why they added that "annoying bong sound"?  Right,
because the warning light kept getting ignored.

--
Hans-Bernhard Broeker ( snipped-for-privacy@physik.rwth-aachen.de)
Even if all the snow were burnt, ashes would remain.

Re: Zigbee
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It was the thermostats that were the problem.  And I wouldn't be
monitoring them off site, it would be in my house.

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not

And so, if I'm worried about that, I turn that feature off (or more
correct in terms of security, I never turn it on).  If not, I do what I
want with it.

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And he gets access to this how?  Yes, we may be talking wireless here,
but I certainly am not talking open networks.  I'd expect a fairly
healthy level of security to be in place.  Sure, nothing is
unbreakable, and some are easily broken (see WEP), but lessons have
been and are being learned.

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well

I want to buy my appliances where you buy them, then.  A $0.30
refridgerator,  water heater or cordless phone sounds like a sweet
deal.

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Because it was in a car and driving with an open door is dangerous.
Leaving my garage door open is usually costs heating/cooling bills, or
perhaps a security problem that an alarm system would note when you
went to arm it for the night.

The point is, not everyone will want these types of things, but some
will.  Look at how many people have suffered through X-10 setups (and
those who've actually managed to make them work), and you can tell home
automation isn't something that no one wants.  Some people do want it.
Some people will build it.  Some people will buy it.


Re: Zigbee
On 9 Dec, in article

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If power has stopped getting to the freezer or its control micro that it
would need to network the data fails it is of no use. Putting extra bits
onto a 'central computer' to always expect a message from each device and
alarm when one times out is extra cost and development.

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Those sorts of problems have safety devices to deal with those problems
that MUST by regulations (in most countries) be simple devices on the
the equipment. Thermal cutouts and pressure release valves have been around
for over 100 years (nearer 200).

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Most devices that have incorporated those over the years have nearly always
ended up with them either removed or not used. Many cookers (and microwaves)
have or still have bells/buzzers on them for such purposes, even I have
known many cookers/ovens that had mechanical clocks and alarms years ago.

People once they have had one generally don't see it as essential when
they get another one.

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As someone else said how are you going to process and sort that much data
into anything of any real use beyond the first couple of quarters when it
is new and interesting. Beyond that it becomes a chore and either the tail
starts wagging the dog or like cooker timers, does not get used.

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You might, but there is still a large amount of the population 'stuck in
the old ways' who are the main people actually doing the cooking etc.
Many are technophobes, and find that most of these UI implementations
are overkill and like a lot of online ordering, it is quicker to do it
the old way as the UI is too long and complicated. Like a lot of people
I know find the ordering processes laborious and long so find the information
then phone up an order!

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I agree a more sophisticated heating system would be nice to load lots
of presets like "I am having three days off so heat all day" would be nice.
Unfortunately most web interfaces I have seen go two ways

        1/ Web limited copy of existing poor UI and restricted timing
           patterns.

        2/ Over the top highly graphical, with lots of logos and other
           marketing information, with too many pages and steps to set
           things up.

This is the same as networked printer web interfaces.

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That is for those who have bothered to look up statistics for themselves.
Most gardeners know from watching the weather, or the weather forecast/channel
information.

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So prone to be disabled or ignored like a lot of reminders and other things
in cars.

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This type of over the top is what a very small percentage of the GLOBAL
population want and most of those are the gadgeteers and early adopters
looking for something new not what they actually need.

Just because gadgeteers want to buy it, does not mean their is a big
enough market to produce it.

You can get all sorts of home automation already including automatic and
remote controlled lights and curtains, to sometimes link in with your
security system. How many people do you know that actually have these?
They have been around for years!

--
Paul Carpenter          | snipped-for-privacy@pcserviceselectronics.co.uk
<http://www.pcserviceselectronics.co.uk/ PC Services
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Re: Zigbee
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And this is a good example of overkill.  Unless you live in an
area with very unreliable electrical service, you rarely have
to set clocks.  Some of us don't even bother to reset all of
them when the U.S. switches to daylight wasting time.

Re: Zigbee
snipped-for-privacy@mindspring.com says...
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Wrong question.  The first question is not why network to co-ordinate
time but why does it have a time of day clock to begin with?  I long ago
stopped setting the clock on my microwave for instance, I have absolutely
no desire to use it for a clock I just want it to warm my food.  My
kitchen clock is a far better clock than my microwave ever will be.

Feeping Creatures!

Robert

Re: Zigbee
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Fair enough.  However, the VCR, and the kinds of coffee makers that can
automatically make my coffee so that it's ready when I wake up in the
morning both have a genuine need for time of day.

Also, as an extension to your argument, you could say that if all
members of the household have reasonably accurate wristwatches, then all
clock displays are unnecessary.

Ed


Re: Zigbee
snipped-for-privacy@mindspring.com says...
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The VCR and coffe maker I'd accept, although I'd question how many
people actually use that feature in either one. The trouble with clocks
on all and sundry devices is the tryanny of timekeeping.  We feel
compelled to set them, guilty if we don't set them and feel as if we
should track every tick and tock as we are continually remided of the
relentless count of time.

 
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Yep, although I'd turn that around, clocks are so all-pervasive and
invasive that I havn't worn a wristwatch in some time.  If I need to know
the time it's already available easily elsewhere (PC, Cell, public clock
most of which appear to reference a more accurate reference source (I
know my PC does)).  If it's not readily available all I usually need to
know is that's it's say mid-afternoon and that is quite readily apparent
w/o any clock keeping technology.

Robert

Re: Zigbee
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Main reason that I wear a watch, these days, is to be reminded of the day
and the date.  They're much harder to discern by looking at the sky.  :-)

Cheers,

--
Andrew


Re: Zigbee

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I'd add to that by saying the ZigBee community have been remarkably
successful at de-emphasising the underlying 802.15.4 wireless
protocol, since they can't make any money from it. You can create a
low-cost 802.15.4-compliant data transport that doesn't use their
code.

Jeremy Bentham
Iosoft Ltd.

Re: Zigbee
Hi Lewin,

That was indeed a nice and concise writing.

In addition, I think that the practical range of Zigbee devices needs to
be thoroughly tested. Wireless gear, even when maxing out the FCC limits
will not always reach where you want it to. For example, in our house
there are several fiber insulated walls. This fiber is aluminum backed
so that wireless usually quits working in the garage or in certain areas
of the deck. Personally I believe low bandwidth PLC is better for motes
and appliances in a household. And that is or would be the main market.

Regards, Joerg

http://www.analogconsultants.com

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