Z-Wave improvement

[nobody@xxxxxxxxxxxx (Dave Houston)]

Intermatic announced their InTouch(tm) Z-Wave based system a year ago (March
2006) but it is just now starting to ship. It addresses two Z-Wave
weaknesses which I have been pointing out for the past 3 years or so.


http://www.intermatic.com/images/news/InTouch%20Launch%20Release%20Final.pdf

First, it increases the maximum number of hops a message can take from 4 to
8. Given that Z-Wave devices need to be within 20-25 feet of each other to
assure coverage, 4 hops severely restricted the size of any Z-Wave network
and I considered it a fatal flaw in the Z-Wave system. 8 hops is a much more
realistic figure.

Second, it employs what Intermatic calls a "server" which is in the
base/charger for the handheld remote. It periodically polls all of the
devices (including legacy Z-Wave devices) in the network and maintains a
status table which can be accessed by other controls.

     http://www.intouchcontrols.com/intouch-technology.php

I still have some questions and haven't been able to find in-depth technical
details to answer them.

1. How often is the network polled? The polling frequency will determine how
up-to-date the status table is but frequent polling may hamper operations by
causing collisions with user generated signals.

1a. Can legacy controllers access the "server"?

2. It's not clear how legacy devices will deal with the increased number of
allowable hops. The remaining hops are embedded in the message and it's not
clear how legacy devices will deal with numbers greater than 4. Perhaps the
original protocol anticipated larger numbers.

Intermatic says they've applied for patents so their approach may or may not
show up in other Z-Wave systems.

Prices for InTouch(tm) devices are approximately 3x those of comparable
devices in Intermatic's HomeSettings(tm) line of legacy Z-Wave products.

     http://www.automatedoutlet.com/home.php?cat=247
     http://www.automatedoutlet.com/home.php?cat=236

Intermatic has started a forum where those interested can get answers to
their questions.

     http://www.intouchcontrolsforum.com/forums/

Finally, I don't know how microwavable it is - it uses the 900MHz band in
North America.


http://davehouston.net
http://tech.groups.yahoo.com/group/roZetta/
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