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----- Original Message -----
Sent: Thursday, May 29, 2008 8:52 AM
Subject: Re: [802.15_GENERAL] [802.19] [802.15_GENERAL] TGn Letter
Ballot Support
Other countries may not have these
primary users on this band... and yes, poeple (the general public) have now
becomed accustomed to using this band a s a reliable service... which it is an
many many countries ( I can't speak for the US, I don't live there)... and
honestly, I don't think that is a reallygood argument in favor of trashing the
band and making millions upon millions of devices become disfunctional. I am of
the opinion that if 802 allows this, I risks getting a balck eye from
the public opion, damage it's brand value and literally be asking
for regulators to step in. Regulator have benn nice with 802, they really
listen to us and accomodate us... I think we ought to be carefull and build that
relationship by carefull work on assuring reasonable coexistence.
I respectfully would like to hear
from the 11n proponents why the 2 GHz band is so important here, why the higher
freqency 5 GHz band is not sufficient ? I would like to hear a balanced
point of view to better understand the need and see what could be done, if the
need is severe.
Ivan Reede
----- Original Message -----
Sent: Wednesday, May 28, 2008 9:46
AM
Subject: Re: [802.15_GENERAL] [802.19]
[802.15_GENERAL] TGn Letter Ballot Support
Hi Ivan,
Critical
systems in the ISM band? Please, lets get real!
Coexistence within the 802 community is a
good thing, but that is not the universe.
Is any one still aware that the 2400
to 2450 MHz portion of the 2400-2483.5 MHz ISM is shared by primary and
secondary services that take precedence over unlicensed users? These licensed
users include radio amateurs operating under Part 97, and Federal
radiolocation users operating under NTIA.
In part, the amateur
regulations read:
97.303 Frequency sharing requirements.
...
(2) In
the United States:
(iii) The 2390-2417 MHz
segment is allocated to the amateur service on a primary
basis.
...
(B)
Amateur stations operating in the 2400-2417 MHz segment must accept harmful
interference that may be caused by the proper operation of industrial,
scientific and medical equipment.
(iv) The
2417-2450 MHz segment is allocated to the amateur service on a co-secondary
basis with the Federal Government radiolocation service. Amateur stations
operating within the 2417-2450 MHz segment must accept harmful interference
that may be caused by the proper operation of industrial, scientific, and
medical devices operating within the band.
...
Part 97..313 Transmitter
power standards.
(b) No station may transmit with a transmitter power
exceeding 1.5 kW PEP. [Note: there are no restrictions on antenna
gain]
----------
In that context, lets be mindful of what
802.Whatever is governed by:
Section 15.5 General conditions of
operation.
(a) Persons operating intentional or
unintentional radiators shall not be deemed to have any vested or recognizable
right to continued use of any given frequency by virtue of prior registration
or certification of equipment, or, for power line carrier systems, on
the basis of prior notification of use pursuant to Section 90.63(g) of this
chapter. [Should reference Section 90.35(g).]
(b) Operation of an intentional, unintentional, or incidental
radiator is subject to the conditions that no harmful interference is caused
and that interference must be accepted that may be caused by the operation of
an authorized radio station, by another intentional or unintentional radiator,
by industrial, scientific and medical (ISM) equipment, or by an incidental
radiator.
(c) The operator of a radio
frequency device shall be required to cease operating the device upon
notification by a Commission representative that the device is causing harmful
interference. Operation shall not resume until the condition causing the
harmful interference has been corrected.
Parts 15.5 (b) and
(c) protect the primary and secondary users of the spectrum; but while
(c) does not apply to radio amateurs (see part 97.303 (iv) above), no protection is afforded to 802.anything.
I
wouldn't worry about your neighbor's 11n device taking out your HVAC system.
Cheers
Kai Siwiak
Ivan Reede wrote:
B443B700845C4E0481FDAD2795B55C68@A642200R type="cite">
Benjamin, you make an interesting point.. I
would like to add a little twist to it.
If your HVAC system uses a 802.15.4
stops working because you just turned on a new 11n system, well, yes
you will not appreciate and will probably return it. That' self
coexistence... the owner with himself, the easy part.
However, if you are gone for a week and your
neighbor gets a new 11n device... I'm not sure how you'll
appreciate your frozen pipes and the water damage when you come back...
and how you'll appreciate your HVAC technician bill when he tells you there
is nothing wrong with your HVAC system, that you just have to replace its
control elements and start pulling wiring to replace the wireless controls
you paid a premium for... because "someone" in the area just fired
up an 11n system and either doesn't know or worse, doesn't care because
"he's" not affected...
That was the nice case. Now I'm not sure how
you'll like the repeated service calls (and service charges and loss of
trust in the system reliability) to the HVAC tech if the 11n device is in a
portable device and appears as an intermittent failure source for your
HVAC system, driving you HVAC tech crazy ... when he's there, no 11n device
in the area... nothing wrong with the system... from time to time, when he's
gone, the HVAC system fails due to the sproadic presence of the 11n
system.
I think we have to consider the hardship X10
lived through because of sporadic house lights turning on in the middle of
the night, etc... if 802.11n units start causing things like that to
802.15.4 devices... its very possible that the public's perception of the
overall environment may damage the "trust" the public and the
regulators have in the 802 "brand" name on many products.
----- Original Message -----
Sent:
Tuesday, May 27, 2008 12:15 PM
Subject:
Re: [802.15_GENERAL] [802.19] [802.15_GENERAL] TGn Letter Ballot
Support
Hi All,
I am not able to post to the 802.11n but I
hope one of you that can will ensure this thread gets circulated there so
that TG members not on our dot 15 reflector get in on it.
Ivan makes the good point that the non-802.11
device is not able to signal it's inability to tolerate something using
802.11 protocols. I've been looking at what I think are the relevant
sections of the draft:
11.14.11 Signaling 40 MHz
intolerance, 11.14.12 Switching between 40 MHz
and 20 MHz
11.14.12 answers how a non-N legacy 802.11
device may "signal" if I read it right: the reception of a legacy beacon
(TE-A) shall cause "re-evaluation". You might note that in draft 5
the reference given here for how "re-evaluation" is done points to a
subclause number which does not appear to exist ("shall re-evaluate the value of the local
variable 20/40 Operation Permitted (see 11.9.8.3)")
I've not been able to find on the
document server any presentations on coexistence with non-802.11 spectrum
users in a quick search. What would help tremendously is if someone could post specific references to
he coexistence analysis, simulation results, and (most helpful) field
measurement results of existing "almost N" devices. From my limited
knowledge of 802.11n see a very significant potential for problems.
I'm sure I'm missing key points as to how this mechanism is intended to
work, so any explanation of why this is not a severe coexistence problem
would be greatly appreciated. As I read it, there is no coexistence
consideration at all for non-802.11 systems.
What concerns me most about this discussion
is that it seems to illustrate that some in dot-11 are working with a
very narrow view of coexistence. I've only been able to briefly look
through draft 5, and I see a good
amount of verbiage about coexistence with participating 802.11
systems, and interoperability with legacy 802.11 systems. Representing a
consensus of one, I can assure you that is not nearly broad enough to
ensure success in the ever more crowded space of 2.GHz (that is my opinion
which plus $3US will get you a cup of coffee). I'm not
suggesting that there are not good, reassuring arguments an analysis which
may attenuate these concerns, just that if there are, I've not seen them
yet.
To Matthew's second point, I have to agree in
principle (enthusiastically) that standards are better than non-standards,
and we must remember that 802 in the world: we are not a regulator.
Providing a standard-defined behavior is better than a plethora of
non-standard wireless systems competing, and as Ivan points out, one can
define an ISM device which is very unfriendly under the current
rules. Keep in mind that if this becomes a problem as perceived by
our esteemed regulators, then rules changes will be made (and odds are non
of us will like the result all that much). Also keep in mind
if users find 802.11n use annihilates their Bluetooth, shuts down
their HVAC system, or otherwise fails to get along in the spectrum
with all the other stuff they've got, They'll abandon those 802.11n
devices the entire effort of TGn and the vendors building to it will
be for naught. Vendors may go ahead and produce non-standard
products, but if they are not spectrum friendly, they'll find it an
unsatisfying endeavor.
-B
================================
Benjamin
A. Rolfe
408.395.7207 Office
408.332.0725 Mobile
Skype:
benjamin.rolfe
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----- Original Message -----
Sent:
Monday, May 26, 2008 9:50 AM
Subject:
Re: [802.15_GENERAL] [802.19] [802.15_GENERAL] TGn Letter Ballot
Suppo
more on coexistence.
At
08:20 AM 5/26/2008 -0400, Ivan Reede wrote:
My
question on this is simple....
How does a device,
which does not have a clue of the 802.11 modulation and MAC mechanisms
form a message that will "set" the magic bit?
The next obvious
question follows: How does a low power device, with a shorter range
and lower transmitting power than an 802.11 device, signal anything to
a 802.11 device that prevents it from operating if the 802.11 device
is bewyond the low power, short range device. How doe a 10 meter range
device tell an problematic 802.11 device at 30 meters to switch to the
20 MHz mode?
The next one is, how does one protect 802.11 devices which
claim to have a higher transmission speed to be attacked by another
device that simply signals it to reduce its speed. To me, this sounds
pretty bad... the comnsumer buys a device that claims to go faster,
puts it in a "normal" urban setting (where meny devices go) where alot
of legacy devices are present and ends up wirth a device that will not
perform at the higher speeds.
Next, how does an
older device perform when a new device comes along... if it does not
know how to signal the "magic" bit to tell the new device to slow
down... we have millions of 02.11 devices deployed at 2.4 GHz. Are
they going to be negatively impacted. Is that in agreement with the 5
criteria we all work so hard on when we create a PAR?
A question for the
EC and the IEEE SA, sonsors of 802 projects. Once a project has been
approved, is the body authorised to override the PAR's scope and most
importantly, is the body authorised to override the 5 criteria that
were required to approve the PAR, even if the limitations imposed by
any of these 5 criteria is not explicitly set out in the scope. I am
seriously concerned by this last question. My feeling for having
participated in many groups is that I have the growing perception
whereby there appears to be a forming mindset that a PAR is simply
something to make the EC happy and that once the prject has been
authorised, any thing goes, the project body has ultimate power. I
think the body has been delegated a limited power by the EC to create
a standard wtihin the bounds of the project's scope and the 5 criteria
upon which it was authorized and that this ought to be well
communicated to the working group members.
As far as people
making things that are beyond the standard, I have to fully agree, its
about time we set limits to proprietary things that can be "added" to
comlpiant devices and still claim compliance to a standard. What would
happen for example, if a manufacturer decided one day to make an
802.11 complaint device have a special mode that could be set by the
user, whereby it would transmit a carrier whenever it wants, under
user control. That device could pass all 802.11 compliance tests with
that mode off, yet, when another of his devices happens be be in
vicinity, he could recognise it and both could agree to "pre-emt" all
neighbouring devices by killing them via the carrier sense mode. That
would give the 2 devices an unfair advantage over other devices that
respect the "carrier sense" by shutting them off... but would that be
a compliant device? Yes, I do support prduct vendor can make additions
to devices that give them an edge in so much as they respect the spit
of the standard and in general, improve the orverall system
performance and I would not like to curtail that, yet, I think there
are limits to these if they break some of our basic principles, like
network access fairness and I am not sure how we could make those
"implementations" non-compliant.
As you can see, I
have many questions which beg for hard answers. This is food for
thought. How does 802 make sure that compliance promotes coexistence
between vendors and all 802.xx compliant wireless products in
general?
Ivan Reede
- ----- Original Message -----
- From: Shellhammer, Steve
- To: paul.nikolich@att.net ; bkraemer@marvell.com ; carl.stevenson@ieee.org ; david.cypher@nist.gov ; eldad.perahia@intel.com ; I_reede@amerisys.com ; john.barr@motorola.com ; Joseph.Levy@InterDigital.com ; Mark.austin@ofcom.org.uk ; mjlynch@nortel.com ; nada.golmie@nist.gov ; ppiggin@nextwave.com ; bheile@ieee.org ; Shellhammer, Steve ; sli@sibeam.com ; swhitesell@vtech.ca ; vivek.g.gupta@intel.com
- Cc: bill.shvodian@ieee.org
- Sent: Sunday, May 25, 2008 11:16 PM
- Subject: RE: [802.19] [802.15_GENERAL] TGn Letter Ballot
Support
- I wanted to forward this
onto those who are not on the 802.19 reflector
- Steve
- From: Bill Shvodian [mailto:bill.shvodian@gmail.com] On Behalf Of
Bill Shvodian
- Sent: Sunday, May 25, 2008 7:16
PM
- To: Shellhammer, Steve
- Subject: RE: [802.19] [802.15_GENERAL]
TGn Letter Ballot Support
- Steve, I am not an 802.19
member, but I monitor the reflector so I am not doing a
reply-all. I think that 40 MHz operation should be banned by
the FCC and other regulatory agencies. I think .19 and .18
should be active on this. There are 2 billion
Bluetooth/802.15.1 devices deployed that will be adversely impacted
by 40 MHz 802.11n devices. You and others did a lot of good
work to help 802.11 and 802.15.1 devices coexist and this definitely
will not help. The 40 MHz intolerant bits seems nearly useless
to me.
- Bill
Shvodian
- Director of
Standards
- NII
Holdings
- From: Shellhammer, Steve [mailto:sshellha@QUALCOMM.COM]
- Sent: Sunday, May 25, 2008 2:38
PM
- To: STDS-802-19@LISTSERV.IEEE.ORG
- Subject: Re: [802.19] [802.15_GENERAL]
TGn Letter Ballot Support
- IEEE 802.19
TAG,
-
Paul Nikolich would like the opinion of the 802.19 members on the 40
MHz 802.11n discussion.
-
If you have an opinion to share please “reply-all” so that everyone
can hear your opinion.
- Regards,
- Steve
- From: Paul Nikolich [mailto:paul.nikolich@att.net]
- Sent: Saturday, May 24, 2008 7:06
AM
- To: Shellhammer, Steve
- Subject: Fw: [802.15_GENERAL] TGn
Letter Ballot Support
- Steve,
- What is dot19's opinion on the below
debate?
- --Paul
- ----- Original Message -----
- From: Matthew
Fischer
- To: STDS-802-WPAN@LISTSERV.IEEE.ORG
- Sent: Friday, May 23, 2008 10:29
PM
- Subject: Re: [802.15_GENERAL] TGn Letter
Ballot Support
- I will be voting YES on
TGn LB129, and I would urge others who are interested in defending
802.15.x devices' access to the ISMii band to vote YES as
well.
- The current draft of the
802.11 TGn amendment contains normative language describing a
mechanism (i.e. the 40 MHz Intolerant bit) that allows non-related
devices to signal to the 40 MHz TGn devices that they cannot send 40
MHz transmissions, effectively allowing other users of the ISMii
band to restrict the use of 40 MHz transmissions by TGn devices. 40
MHz 802.11 TGn devices are required to obey this signaling whenever
it occurs.
- If 40 MHz operation is
forbidden in ISMii by 802.11 TGn, then 40 MHz operation will be
implemented as a set of vendor-specific non-standardized modes with
variable degrees of good citizenship regarding spectrum sharing and
with little or no opportunity for such devices to be controled by
other users of the ISMii band.
- For these reasons, it is
in the best interest of 802.15.x technology providers and other
users of the ISMii band to vote YES on the TGn-standardized mode of
40 MHz operation that includes specific requirements to force TGn
devices to cease 40 MHz operation when requested.
- Matthew Fischer
- Nice Guy
- +1 408 543 3370 office
- +1 650 796 9206 mobile
- mfischer@broadcom.com
- From: John Barr [mailto:john.barr@MOTOROLA.COM]
- Sent: Friday, May 23, 2008 8:36
AM
- To: STDS-802-WPAN@LISTSERV.IEEE.ORG
- Subject: [802.15_GENERAL] TGn Letter
Ballot Support
- As mentioned in Jacksonville, the
current draft of TGn includes use of 40 MHz channels in 2.4 GHz
spectrum. This will significantly impair ability of other IEEE
standards using 2.4 GHz spectrum to coexist with TGn devices running
at 40 MHz. Even though the rejection of my comment number 6069
states that there is provision for coexistence with other radio
systems using 2.4 GHz spectrum, the actual text for this is
informative and does not actually include tests for IEEE 802.15.1
nor IEEE 802.15.4 devices. See attached note to TGn I sent during
the Jacksonville meeting. At the one session where there was any
discussion on my comment, I spoke against the resolution and no one
spoke for the resolution rejecting my suggested change (not to allow
any use of 40 MHz channels in 2.4 GHz spectrum). (See
attached)
- As it current stands there is no clear
method to prevent use of 40 MHz channels in 2.4 GHz when IEEE
802.15.1 and 802.15.4 devices are operating in the same
spectrum.
- You can vote against the current TGn
letter ballot by referencing my comment (6069) that is unresolved
(not accepted by the submitter) and requesting the same resolution:
In 20.3.15 change "When using 40 MHz
channels, it can operate in the channels defined in 20.3.15.1 and
20.3.15.2." to "When using 40 MHz channels, it can only operate in
the channels defined in 20.3.15.2."
- James Gilb may be able to clarify just
how to vote on this. Voters who previously approved the original LB
can change their vote to disapprove based on this
comment.
- Thank you for your
support.
- Regards, John
- --
- John R. Barr (John.Barr@Motorola.com)
- Director, Standards Realization - <http://www.motorola.com>
- Vice Chairman of the Board, Bluetooth
SIG - <http://www.bluetooth.org>
- (847) 576-8706 (office)
+1-847-962-5407 (mobile) (847) 576-6758 (FAX)
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Bob Heile, Ph.D
Chairman, ZigBee
Alliance
Chair, IEEE 802.15 Working Group on Wireless Personal Area
Networks
11 Robert Toner Blvd
Suite 5-301
North Attleboro,
MA 02763 USA
Mobile:
+1-781-929-4832
email: bheile@ieee.org
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