Memorandum submitted by the Radio Society
of Great Britain
(1) KEY POINT
SUMMARY
The RSGB supports the ideal of broadband availability
to all households, however, the membership of the RSGB and Radio
Users in general are concerned with aspects of some particular
technologies which are being used to implement broadband provisions
in the United Kingdom.
Our submission will highlight the inappropriate
use of particular technology, such as PLT, which impinges on the
High Frequency spectrum between 1-30MHz.
(2) OUR STATUS
The Radio Society of Great Britain represents
Radio Amateurs, and Shortwave Listeners in the United Kingdom.
With a membership of over 25,000, it is the voice of nearly half
of the licensed radio transmitting stations in the UK.
The RSGB is well represented within the International
Amateur Radio Union (IARU), and our President is a key Committee
Chairman within the International Telecommunication Union (ITU).
The Society attends and contributes to the Committee
working of BSI, CISPR, ITU and ETSI.
(3) USE OF
THE HF RADIO
SPECTRUM
Contrary to common belief the use of the HF
spectrum is as full and busy as ever. The Broadcasters, the Military,
Commercial Users and Radio Amateurs fight for primary use of segments
of the spectrum at the World Administrative Radio Conference held
every four years. The committee should be aware of the renewed
interest from the broadcasters wishing to promote Digital Radio
Mondiale Services.
The importance of Amateur Radio as a back-up
emergency service was especially highlighted by the catastrophic
effects of the Asian tsunami and earthquakes. Many countries in
the Pacific region acknowledge the importance of well-trained
HF radio enthusiasts in emergency situations. Even with a highly
developed infrastructure such as existed in New York, Amateur
Radio was highly praise by President Bush for its contribution
following the World Trade Centre disaster. In that case almost
all Wire-Line and Cellular communication failed for several days.
Amateur Radio was as ever ready, it was identified as the emergency
response service that worked most effectively.
Commercial radio users are returning to the
HF spectrum because it offers a cost effective alternative to
the digital satellite services offered by organisations like INMARSAT.
HF radio is used by ships at sea, when out of range of VHF Coast
Stations, and airline operators for aircraft flying in the mid-Atlantic,
and the very long trans-Pacific routes.
There are strong and compelling arguments for
the preservation of a low ambient noise floor in the HF Spectrum.
There are many pseudo-Government users, Civil
Aviation Authority, Maritime Communications Agency, and even direct
Government users, who express concerns regarding the pollution
of the spectrum. They do not express these concerns publicly for
fear of causing public alarm. The committee should have no doubts
about the concerns however. There exist many technical papers
expressing these concerns for such quarters as NATO (see note
2), and broadcasters.
We would urge the committee not to overlook
the social impact of Short Wave listening in our multi-cultural
society. Many SW listeners are tuned-in on a regular basis to
the radio stations abroad for news from their "home"
countries. This has become particularly important with the enlargement
of the EU, and whilst the internet provides a link for the more
affluent, as this inquiry make clear, broadband is not yet available
for all.
(4) OUR CONCERN
The HF spectrum up to 30MHz is a precious resource
which needs to be protected.
The ITU recognised this important tenent in
the early years of radio, and put in place measures intended to
protect the spectrum for use in Broadcasting, and worldwide radio
communication. The Comit
international sp
cial des perturbations radio
lectriques (CISPR) was formed in 1934 to establish
standards for the control of emissions to and from electrical
apparatus, which might impact the radio spectrum.
The work of CISPR continues, with much of its
work now being focused on the impact of digital technology.
Digital Revolution has had a positive impact
on communication with improvements in signal quality, more choice
for the consumer, and in the near future a considerable reduction
in power usage at the transmitter sites. Most of the applications
of technology have had a welcomed and desirable effect.
However, an inappropriate use of technology
can be cited for Power Line Communication (also known as Power
Line Telecommunications) PLC/PLT.
CISPR has not been able to agree revision of
the existing standards, which would accommodate PLT, and maintain
the protection to radio services.
(5) POWER LINE
COMMUNICATIONS
This technology is available in two forms, Access
PLT providing communication to and from the home, and in-Home
PLT for communications entirely within the home. Fortunately all
trials of Access PLT in the United Kingdom have been closed, and
except for some specialised applications in tower-block apartments,
there does not appear to be an appetite for roll-out of this technology
at present.
In-Home PLT has however become a consumer product,
with many manufacturers offering Power Line Adapter, which provide
communication between computers, TV receivers and potentially
any other PLA equipped electrical appliances within a household.
Both of these technologies cause interference
to Radio Users in the HF Spectrum.
See note 1
The ITU has stated its position, quite clearly.
It regards the technology as an unintentional radiator, and has
placed a requirement on international standards makers, "that
existing standards should not be changed or modified in order
to permit PLT, except that any change shall provide the same level
of protection for radio services".
(6) THE STANDARDS
BACKGROUND
We wish to ensure that the committee understand
that all existing PLT devices, whether they be for "access"
or "in-Home" usage do not meet the internationally agreed
emissions standards. In fact most exceed the limits set by 30dB
(1,000 times).
In order to placate the Radio Amateurs worldwide,
mitigation measures have been put in place, and to try to placate
Short Wave listeners some additional mitigation techniques have
been proposed.
The fact remains however, that the established
limits will be exceeded where the mitigation measures do not apply.
Furthermore, the Society, and many other Radio Users doubt the
value of the proposed mitigation measures.
Interference and its impact
Any egress of signal energy for PLT systems
may be undesirable to a nearby listener, and the aggregation of
signals from many millions of these devices will raise the ambient
noise floor on a worldwide scale.
Various reports from authorative sources have
shown that the noise floor will rise by between 10dB to 15dB.
See note 2 and 3.
Since a radio user may be operating on very
weak signals, this could mean the difference between successful
communication, and none at all. The same applies to a short wave
listener. See note 4.
We draw to the attention of the committee, that
whilst radio users accept a signal to noise margin of 10DB as
being acceptable, PLT systems are set-up to have a massive headroom
margin of 30dB.
In the United Kingdom over 190 cases of
interference have been reported to the Regulator (Ofcom) and of
those over 120 have been remedied by removal of the interference
source, a PLT modem.
We would like the committee to make note of
the fact that radio communications is the subject of an 11 year
sun-spot-cycle. At the present (2009), we are just beginning to
emerge from a period of extremely poor propagation of signal around
the world. By 2014 communication will have recovered, and
it will be possible to communicate with a very minimum of transmitted
signal power. It is at this stage that the severity of egress
from PLT systems into the HF spectrum will become evident.
Immunity Issues
PLT can provide point to point communication
on a sound but not altogether reliable basis. Whilst it is a cause
of interference it is not particularly immune from interference
to its operation. It is adversely affected by noise present on
the mains network wiring.
In-home PLT, which may be installed by the consumer,
is particularly vulnerable to house wiring configuration. The
sources of interference that adversely affect this technology
are numerous. Nearby radio transmissions in the HF spectrum will
frequently cause "blocking" of PLT signals.
The committee should take the seriousness of
diminution of throughput into account, as a factor in favour of
alternative technology.
Recommendation to the Committee
The RSGB strongly urge the Committee to consider
and recommend the use of Fibre Optic and Wireless (Wi-Fi) systems
in preference to PLT technology.
The promise of Fibre to the Curb-side within
the foreseeable future has already been made. The last hurdle
(no longer the last mile); will be distribution into the home.
It is our belief that this will be best accomplished by continuing
the fibre, or by providing localised Wi-Fi access for user communities.
BERR should work with and encourage Ofcom to
release spectrum above 500MHz for this purpose, as part of the
Digital Dividend.
The RSGB recognise that the implementation of
"Smart Grid" may require each and every household to
be connected- although not necessarily on a broadband service.
However the prospect of every one of 15 million households, each
with an individual IP address raises the issue of aggregation
of interference to a new height. We hope that the Committee will
consider this.
We urge the Committee to ensure that the undertaking
given by Ofcom to investigate interference complaints is maintained.
See Note 5.
REFERENCES
(1) ITU, Doc. 1/101-E and 1/102-E, and Doc. 1A/117-E,
1A/118-E
(2) NATO Doc. RTO-TR-IST-050, AC/323(IST-050)TP/44,
(ISBN 978-92-837-0069-2)
(3) ITU, Doc. 1A/35-E
(4) ECC Recommendation (05)04, Criteria for the
Assessment of Radio Interference caused by Radiated Disturbance
from Wire-Line Telecommunications Networks
(5) Wire-Line_Event_09 PowerPoint presentation,
hosted by DTI/Ofcom. See slide 20
October 2009
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