John,
I’m not really an expert but I’ve
been trying to follow things. I think you should talk to Carl who is
pretty avidly against this technology because of interference issues (primarily
in the HAM bands). I tried very hard to bring a PAR like this into IEEE802,
but certain folks (I have to give credit to Carl again here) strongly objected.
First, I think this PAR clearly belongs in
802. But when I tried to bring it here, we drove it away. Hence
they have now gone elsewhere.
Here is my view on things. This
technology definitely is an interference issue. On the other hand, it is
already being deployed and I see no way of stopping it. I’d rather
have it in 802 where we have the most chance of influencing it and controlling the
interference issues. If it goes somewhere else (as it has), I feel we
have the least chance of influencing it, and it will be more of an interference
issue.
Most versions of this technology operate
in lower bands than say 802.11 (<100 MHz). I think it is more likely
to be an interference issue for Ethernet than for 802.11. However, there
is at least one version of the technology that uses the powerlines as
waveguides of a sort and actually does operate on 802.11 frequencies. Well
really it works more like a leaky waveguide particularly at corners (I guess EM
waves really do have momentum). Even so, operation at 802.11
frequencies is actually my preferred solution since I think it radiates less at
these frequencies than it would at the lower frequencies. I think the
capacities are higher, and you could even use 802.11, 802.16 or maybe even 802.22
like protocols (once they exist) to run the system. However there is no
doubt that the so called ‘junk’ bands would become even junkier
with this technology. That said, these bands really were designated in my
mind as a protocol free for all, and the protocols fielded are supposed to be
designed to handle that environment. As long as the wires aren’t
radiating more than any other transmitter is allowed in the band I think it
should be permitted. This leaky waveguide effect (assuming it is bidirectional)
could even be an advantageous way to set up a ‘wireless’ infrastructure.
Anyway, that’s my take on things. I
see nothing in this PAR that restricts them from using 802.11 frequencies, so
yes I do believe this is a potential RF interference issue. I further
declare that it could be an interference source to wired infrastructures as
well depending on the power levels contemplated. While they talk about
coexistence, I see nothing about coexistence with other wireless or wired
infrastructure (only within the power line community). We should probably
insist on requirements being added, or at least have them restrict bands of
operation to be <100 MHz. I think that keeps them out of any RF bands
we currently contemplate.
Happy Day!
Mat
Matthew Sherman, Ph.D.
Senior Member Technical Staff
BAE SYSTEMS, CNIR
Office: +1 973.633.6344
email: matthew.sherman@baesystems.com
From:
owner-stds-802-sec@LISTSERV.IEEE.ORG
[mailto:owner-stds-802-sec@LISTSERV.IEEE.ORG] On
Behalf Of John Hawkins
Sent: Monday, February 28, 2005
1:21 AM
To: STDS-802-SEC@LISTSERV.IEEE.ORG
Subject: Re: [802SEC] Another PAR
your WG/TAG may find of interest
Not being the technical expert here, I
would value the input from other EC members on the issue of potential
interference of BPL with other radio technologies.
Of particular interest would be the
propensity of such technologies to interfere with 802 technologies. Is there
any concern? (will my 802.11 access point still work when my power company
fires us BPL?)
Specific to this PAR, should there not be
a mention to adherence of FCC Part 15 rules in some way? Should our 802.19
folks liaise with them to ensure coexistence between 802 wireless work and
another IEEE standard?
-----Original Message-----
From: owner-stds-802-sec@ieee.org
[mailto:owner-stds-802-sec@ieee.org] On
Behalf Of Paul Nikolich
Sent: Friday, February 25, 2005
7:25 PM
To: STDS-802-SEC@listserv.ieee.org
Subject: [802SEC] Another PAR your
WG/TAG may find of interest
I have attached another PAR on the docket for the March
Standards Board meeting that may be of interest to your WG or TAG: Project
1775 "Standard for Broadband over Power Line Networks: Medium Access
Control and Physical Layer Specifications."
Please remeber the Standards Board meetings will take place
in the same location of the 802 Plenary Session on the Fri/Sat/Sun after our
session ends. I encourage you and members of your WG/TAGs to attend the
meetings to become familiar with what happens at that level. I have
attached an agenda for the SASB meeting along with a roster of the SASB.
Please pass it along to your members.
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