Doc: IEEE802.19-09/0097
November 2009
Ofcom Update on the TV White Space
issues
Date: 2009-11-18
Authors:
Name
Company Address
Phone
E-mail
Andrew Gowans
Ofcom
+4420 7981
3191
Andrew.gowans@ofco
m.org.uk
Mark Austin
Ofcom
+4420 7789
4364
[email protected]
g.uk
Riverside House, 2a
Southwark Bridge
Road, London, SE1
9HA, UK
Riverside House, 2a
Southwark Bridge
Road, London, SE1
9HA, UK
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Submission
Mark Austin and Andrew Gowans Ofcom
IEEE802 Interim Meeting Atlanta 18th November 2009
Ofcom Update on the TV White Space
issues
Andy Gowans / Mark Austin, SPG, Ofcom UK
18th November 2009
Contents
• Interleaved Spectrum or TV White Space
– Ofcom Consultation
– European Studies
– Next Steps
Ofcom Consultations on TV White Space
• 2nd consultation on DDR band manager award published 27/06/09 and
closing date 27/09/09. For details see
http://www.ofcom.org.uk/consult/condocs/bandmanager09/ . This will
determine how and who PMSE users in the band will be managed in the
future.
• Statement on Cognitive Radio Consultation published 01/07/09 see
http://www.ofcom.org.uk/consult/condocs/cognitive/ ;
• Consultation on Geolocation for Cognitive Access A discussion on using
geolocation to enable licence exempt access to the interleaved spectrum
published 17/11/09 see
http://www.ofcom.org.uk/consult/condocs/cogaccess/cogaccess.pdf ;
Previous Statement on Cognitive Radio Consultation
– Sensing
• We were not convinced by the arguments that suggested that detection alone cannot
offer adequate protection. However, we noted that implementation of detection-only
devices at the sensing levels being requested is likely to be many years away. We also
concluded that there was little advantage in rapidly making UK only regulations so we
decided to await to align where appropriate with any European or international
regulations being developed for sensing..
– Geolocation
• Geolocation databases appear to bring some advantages in terms of reducing the
probability of harmful interference while enabling efficient use of spectrum, but we fully
recognise the practical difficulties associated with this approach.
• We seen advantages and disadvantages to both detection and geolocation databases.
• We concluded to enable both detection and geolocation databases and allow stakeholders to
determine which approach they prefer. Indeed, both approaches could even be amalgamated.
• We also provisionally concluded on the parameters needed for sensing but noted that further
discussion would be needed as to how a geolocation database might operate. This latest
consultation and discussion document is intended to stimulate and inform such discussion.
MERGED RESULTS SENSING
PMSE
Key parameters for devices from the July
statement
Cognitive Parameter
Value
Sensitivity assuming a 0 dBi antenna
-120 dBm in 8 MHz channel (DTT)
-126 dBm in 200 kHz channel (wireless microphones)
Transmit power
4 dBm (adjacent channels) to 17 dBm
Transmit-power control
Required
Bandwidth
Unlimited
Out-of-band performance
< -46 dBm
Time between sensing
< 1 second
• Table above sets out the key parameters for Sensing that we concluded upon in
July statement and have subsequently proposed for use in studies taking place in
Europe (ECC SE PT43).
•See previous paper 18-09-0091-00-0000-ofcom-update-on-the-digital-dividend –
Cognitive for more details on how these parameters were derived.
GEOLOCATION
The new Ofcom consultation on geolocation
• We realise that the signal levels for sensing proposed in the July statement are
extremely low, so we believe this alternative approach needed to be considered further.
• We see geolocation as a promising alternative to sensing. This is where cognitive
devices measure their location and make use of a “geolocation” database to determine
which frequencies they can use at their current location. Devices are prohibited from
transmitting until they have successfully determined from the database which
frequencies, if any, they are able to transmit on in their location.
• This new consultation and discussion document focuses on geolocation and the
mechanisms likely to be needed for it to work. It is intended to aid the thinking that is
taking place around the world on geolocation rather than as a statement of clear
regulatory intent. As such, it is hoped that it will further discussion and speed the
development of possible geolocation solutions.
• It does not seek to change in any way the decisions on general cognitive access and
sensing set out in our July 2009 statement.
GEOLOCATION
PMSE
Key parameters being discussed in
Consultation
Based on previous work and workshops held with key stakeholders we
believe that the key issues to be addressed in developing a geolocation
approach are:
1. The information to be provided by the device to the database(s).
2. The information returned from the database(s) to the device.
3. The frequency of update of the database(s) and hence the periodicity
with which devices will need to re-consult.
4. The modelling algorithms and device parameters to be used to populate
the database(s).
5. The maintenance of the database(s).
See http://www.ofcom.org.uk/consult/condocs/cogaccess/ for full details.
GEOLOCATION
PMSE
Key parameters being discussed in
Consultation
1. The information to be provided by the device to the
database(s).
We suggest that this be flexible with the device allowed to
select from providing only its location through to providing
location, locational accuracy, device type and preferences as
to the amount of information that it receives. As the device
provides additional information the database can tailor its
response, in some cases allowing higher power levels. We
note that this may require standardisation work around the
protocols to be used.
GEOLOCATION
PMSE
Key parameters being discussed in
Consultation
2. The information returned from the database(s) to the
device.
We suggest that this should be a list of frequencies and
power levels for each geographical pixel or location.
Alternatively, if the device has moved to a different country,
the database might return the address that the device now
needs to send its enquiry to.
GEOLOCATION
PMSE
Key parameters being discussed in
Consultation
3. The frequency of update of the database(s) and hence
the periodicity with which devices will need to reconsult.
Because some licensed uses of relevant frequencies might
require access at short notice – for example some PMSE
users - we suggest that devices be required to recheck the
database at least every two hours.
GEOLOCATION
PMSE
Key parameters being discussed in
Consultation
4. The modelling algorithms and device parameters to be
used to populate the database(s).
We make some detailed suggestions as to propagation
algorithms, assumed device sensitivity and methodology that
would enable the database to derive the list of frequencies
that could be available for cognitive devices from the
information provided about licensed use.
GEOLOCATION
PMSE
Key parameters being discussed in
Consultation
5. The maintenance of the database(s).
We note that someone will need to develop and host the
database and that costs will be incurred. We seek views as
to who should be responsible for the database and on what
terms, where the costs might fall and what role it would be
appropriate for regulators to play.
Contents
• Interleaved Spectrum or TV White Space
– Ofcom Consultation
– European Studies
– Next Steps
European Developments on White Space
European alignment can occur through informal, semi-formal or mandatory processes. An
informal route would entail all countries individually selecting the same standard. A semiformal route might be via a CEPT recommendation that was widely adopted. A mandatory
process might be via European Union (EU) legislation
Technical work is now taking place within CEPT group SE43 on cognitive access, although
this is at an early stage.
CEPT Work (ECC SE PT43) established June 09
•
Remit : To define technical and operational requirements for the operation of cognitive
radio systems in the white spaces of the UHF broadcasting band (470-790 MHz) to
ensure the protection of incumbent radio services/systems and investigate the
consequential amount of spectrum potentially available as “white space
•
Two correspondence groups established
– Determination of detection thresholds
– Requirement for Geolocation database
•
Status of the work and meeting documents can be found at : www.ero.dk > ECC
Activities > WGSE > SE43
Contents
• Interleaved Spectrum or TV White Space
– Ofcom Consultation
– European Studies
– Next Steps
Next Steps
• Closing date for the comments on the Ofcom consultation/discussion document by 9
February 2010. We will give due consideration to all responses in determining the most
appropriate course of action. See http://www.ofcom.org.uk/consult/condocs/cogaccess/
for more detail.
• If we decide to work internationally to achieve harmonisation, it may take some time,
perhaps years, for all the necessary processes to be concluded. At present, the key
points of interaction are with the FCC and the White Spaces Coalition in the US and
within CEPT and the EU in Europe.
• Once we are satisfied that we have taken all relevant factors into account (possibly
including further consultation) and done all that we can to ensure appropriate
international harmonisation, we will proceed with the necessary steps to licence exempt
cognitive access to interleaved spectrum in the UK. This may involve further consultation
including draft regulations and then, in the light of responses, making those regulations.
Because we do not yet know whether and in what form international harmonisation might
be achieved, we cannot give guidance as to how long it might take to reach this stage
• The PMSE Band Manager award in the UK may have effect on our deliberations on the
use of cognitive systems in the white space also as this will determine how and who will
manage the PMSE community in this band in the future.
[email protected]