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Radio and Electronics Association of Southern Tasmanian Inc.
VK7 (Tasmanian) BPL Watch
radio frequency spectrum is an international natural resource.
It is recognized internationally and regulated by the
International Telecommunication Union (ITU)
established by the United Nations. The
International Amateur Radio Union (IARU)
is charged with being the co-ordinating body for all Amateur (or
Ham) Radio interests and spectrum. The Australian member of the
IARU is the Wireless Institute of Australia (WIA)
who acts as the voice for the amateur
radio is an experimental radio communications service:-
Ham’s lead the way with the use voice over IP (VoIP) technology over the internet to link repeaters all over the world. Our modes and techniques in relation to satellite communication, meteor-scatter, tropo-scatter, earth-moon-earth (Moon Bounce - EME), spread-spectrum, fast-scan & slow-scan television, high speed packet radio and regularly talking (not emailing or phoning) people all over the world on a regular basis. Australian amateurs are credited with the development of some of the first successful communications satellites ever launched. There is even a ham station on the International Space Station. This is hardly out dated technology!
Radio amateurs encourage the use and roll-out of broadband. Hams through the technology they utilise are heavy users of broadband. What Hams are against is the interference causing potential of BPL technology.
Radio amateurs have to operate their equipment within strict limits imposed by the Radiocommunications Licence Condition (Amateur Licence) Determination No. 1 of 1997 and the Radiocommunications Licence Conditions (Apparatus Licence) Determination 2003.
We also need to conform to compulsory electromagnetic radiation (EMR) exposure limits and we can be audited at any time by the Australian Communications and Media Authority (ACMA) as to compliance with these standards.
Radio amateurs carefully match their transmitter to the antenna being used therefore minimising the potential for interference caused by impedance mismatching. If interference does result then radio amateurs take very seriously the resolution of interference complaints with the assistance of the ACMA where necessary.
Radio amateurs – “hams” are licensed users of certain parts of the radio spectrum. We have to pass up to three examinations that are regulated by the ACMA and delivered by the WIA to prove we are competent to operate radio equipment in the allocated radio frequency spectrum and within the strict electromagnetic radiation standards.
of the spectrum that we are licensed to operate in is the high
frequency (HF 3-30MHz) spectrum that affords long-distance
communications, across the world. It is this spectrum that current
BPL technology uses indiscriminately.
As a group,
amateurs only use portions of the spectrum, and as individuals we
use just sections of those portions, at any one time. Whereas, one
BPL location uses all of the HF spectrum and leaves no room for
any other user.
BPL systems are an array of radio transceivers using the powerlines as the transmission medium. These powerlines act in some instances as large antennas with dynamically varying characteristics due to power factor correction and changing power network configuration.
BPL operators are not a licensed user of the HF spectrum and yet the technology they are deploying has the potential to cause interference across the whole HF part of the radio frequency spectrum.
(Broadband over Power Lines) or PLT (Power Line
Telecommunications) is a technology to enable the delivery of high
speed data service over the power distribution system.
technology injects high power, high frequency (typically between 2
and 80MHz) signals over the power distribution network to deliver
high speed data services to homes and businesses. This type of BPL
is termed "Access BPL". There is also "in-house
BPL" which uses building wiring to distribute data
service throughout a building. These systems are currently
The issue is that there is a high potential for interference to the high frequency spectrum through the use of this technique. It has been described as "spectrum pollution". This is mainly due to the power distribution network not being an efficient and effective medium for the transmission of high frequency data services.
It creates interference to such a level that a HF spectrum user within the trial area cannot hear or transmit a signal. Due to the nature of the high frequency spectrum and its ability to propagate long distances, this interference can propagate around the world.
This causes great concern about this technology not only now but into the future when the sun-spot cycle improves propagation. The technology is also prone to interference from other transmitters in the area.
the ACMA in their Access
BPL Guidelines admit:
of the electricity supply network to convey BPL signals will
result in the leakage of radiofrequency emissions. This leakage
has potential to cause interference to radiocommunications
Each time a radio amateur operates, he or she listens first to ensure that their transmission will not interfere with an existing communication path. With the presence of BPL, the amateur is prevented from hearing as to whether another communication already exists or not. Thus he or she is prevented from transmitting anything at all, as well as hearing any reply that may have been possible
For more information take a look at:
BPL systems cause interference to radiocommunications services,
this is a demonstrable fact:
BPL systems are intended to be “always on”. Thus:
to the ACMA on the Management of BPL Interference p.11)
Inductive and capacitive injection of radio frequency on to powerlines originally designed to carry power is a very inefficient process and this means that the signal needs to be injected with high power and boosted every 3-4 power poles and this makes the technology more expensive than other competing technologies.
This also means there is a radio frequency transmitter every 3-4 poles that boosts the signal. This also means it is not a cost effective technology in rural areas and relies on densely populated areas (the suburbs) to get any appreciable return on investment.
following table provides an indication of the relativities between
different broadband technology costs:
The State of New Jersey white paper includes additional information from the Shpigler Group report on the deployment cost of competing access technologies:
Deployment Cost Per Subscriber:
Source: The Shpigler Group, United Telcom Council Research, Opportunities in Broadband over Power Line, Final Report at 189, (2004)
BPL is often touted as the solution for internet service provision in rural areas. However Anthony Good in his FAQ on BPL convincing proves this wrong.
In America & Europe - take a look at: BPL Deployment
In Australia - take a look at: ACMA Australia Trials
Summary of overseas trial outcomes: Caslon Analytics
Concluded Deployments: Wikipedia
Owen Duffy – VK1OD conclusions – comments sourced from the VK1OD website
trial - VK1OD conclusion:
amateur station located in the trial precinct would not be safely
able to transmit at all on the 7MHz band because of the high risk
of interference to possibly active stations that would not be
heard through the BPL interference, effectively curtailing all
activity on the band by such a station.
Woomera Online BPL Trial Moruya NSW – VK1OD conclusion:
radio station located in a residential environment where a similar
BPL system was deployed would not be safely able to transmit at
all on the 3.6MHz and 21MHz bands because of the high risk of
interference to possibly active stations that would not be heard
through the BPL interference, effectively curtailing all activity
on the band by such a station.
The first BPL trial in April/May 2004 was conducted by Aurora Energy in partnership with Japan’s Mitsubishi Electric and Tasmanian Internet company KeyPoint. The second BPL trial started in late August 2005 and is being conducted by Aurora Energy again in partnership with Japan’s Mitsubishi Electric and Aurora's telco company Tastel.
The first trial occurred in April/May 2004. It provided broadband internet to 4 houses (23-29 Kirksway Place and the 1st and 2nd floors of the Aurora office building in 21 Kirksway Place, 7 users all up. Mitsubishi engineers from Japan installed the equipment.
More comprehensive report on the trial can be found HERE.
The second trial commenced on August 29, 2005. The trial will cover 500 homes in Mt Nelson/Tolmans Hill, Burnie and Hobart areas. The trial will run for 9-12 months and the success of the trial will apparently depend on the number of subscribers to the Tastel BPL service.
Pole installations around Hobart:
Application Used: SPECTRAN
If you believe you are being affected by BPL interference we suggest you contact the WIA BPL Interference Advisory Service.
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