director ibec/tif presentation may 2010 · •dynamic spectrum access •spectrum sharing...
TRANSCRIPT
Prof. Linda Doyle
Director
IBEC/TIF Presentation May 2010
Trinity College (headquarters)
Dublin Institute of Technology
Dublin City University
National University of Ireland
Maynooth
University of
Limerick
University College Cork/
Tyndall National Institute
- industry informed research in telecommunications
- optical and wireless domains
interesting things about spectrum
• dynamic spectrum access
• spectrum sharing
• opportunistic spectrum usage
• spectrum etiquettes
• spectrum trading
• technology and service neutral
spectrum regimes
interesting things about spectrum
primary user = licensed
secondary users = cognitive users = unlicensed?
F1F2F3F4
the carriers are orthogonal => tightly packed.
cognitive radio
Cognitive
Engine
Objective
Function
Policies
Allowed frequency bands for primary/secondary use
Maximize SNR, data rate
Occupied bands
Signal strength
Meters Knobs
Neighbour list
Frequency of
operation
Power
Waveform
18
Thomas W. Rondeau, Application of Artificial Intelligence to Wireless Communications,
Ph.D. Dissertation, Virginia Polytechnic Institute and State University, 2007
not so dynamic dynamic spectrum access
Digital dividend - TV white space
digital TV signals will continue to use the
spectrum between 54MHz and 698MHz but there
will be geographical based empty spots
TV White Space
New American Foundation
the database view is winning out
the debate in general is hotting up
WiMAX? 802.22? LTE? LTE+???
FP7 - COGEU
Instituto de Telecomunicações –Portugal
THALES Communications S.A. - France
Rohde & Schwarz - Germany
Portugal Telecom Inovação - Portugal
Sigint Solutions -Cypres
Poznan University of Technology - Poland
University of Aegean - Greece
Institut für Rundfunktechnik - Germany
cognitive radios
FPGA
GPP Platform
Cell BEPicoArray
© Linda Doyle CTVR, Trinity College
cognitive radio – enabling a new kind of commons
– learning an etiquette
need to understand the context in which a system is
operating to do this – need to adjust operation
Even the highly popular 2.4GHz band
is only around 20% used on average
and 40% used in the busiest
locations. The 5GHz band, seen by
many as an “overflow” when 2.4GHz
becomes overly congestion, is almost
completely unutilised.
spectrum trading?
SLOW
some countries that allow
trading
• Guatemala
• New Zealand
• Austraila
• UK
• USA
Europe - Flexible User Rights and Spectrum Trading
• The RSPG launched a consultation on secondary trading of
spectrum in February 2004 following a request received
from the EC in 2003 for an opinion on secondary trading.
In November 2004, the RSPG published its Opinion on
secondary trading.
• RSPG has adopted a cautious stance with regard to
spectrum trading considering it to be “beneficial in
certain parts of the spectrum” and that “European
administrations should introduce secondary trading with
due care”.
• The EU now proposes that one-third of the spectrum below
3GHz could have flexible usage rights and be tradable by
2010.
• RSPG is elaborating on the concept of Wireless Access
Policy for Electronic Communications Services (WAPECS)
to move away from too narrowly specified allocations and
applications, for which specific spectrum is designated.
DYNAMIC
© Linda Doyle CTVR, Trinity
College
tim
e
frequency
space
subletting
sub-subletting
Hierarchical Market Mechanism
Service &
Technology
Neutrality
different from current licensing
FDD FDDTDD
TDD 1 TDD 2
FDD
UPTDD
TDD
1
TDD
2
FDD
DOWNTDD
whatever?
frequency
whatever? whatever?
© Linda Doyle CTVR, Trinity
College
Bansal, G., M. J. Hossain and V. K. Bhargava,
“Optimal and suboptimal power allocation schemes
for OFDM-based Cognitive Radio systems” , IEEE
Trans. Wireless Commun., 7(11): 4710-4718, Nov.
2008.
high order modulation
low order modulation
higher power
lower powerAzarnasab, Ehsan; Kempter, Roland; Patwari,
Neal; Farhang-Boroujeny, Behrouz Filterbank
Multicarrier and Multicarrier CDMA for Cognitive
Radio Systems. CrownCom 2007.1-3 Aug. 2007
Page(s):472 - 481
sculpting techniques
• SETUP: 3 pairs of “1 Laptop+1 USRP” for interfering Tx, primary Tx and primary Rx
– Laptops run baseband TX and RX chains implemented on Iris 2.0
– Baseband samples transferred to/received from USRP over USB
– USRP transmits/receives signal over air
Suppression of adjacent channel interference through shaping
No shaping → Harmful adjacent interference, no audio
whatever?
frequency
whatever? whatever?
dynamic masks
(service & technology neutral)
choice goes to spectrum consumer
(conservative old technology)
frequency
self-induced guardbands
choice goes to spectrum consumer
(sophisticated techniques)
frequency
choice goes to spectrum consumer
(bargaining with neighbours)
time t = t0
time t = t1
coasean bargaining?
thanks
Australia
• There are about 22,000 geographic
cells which vary in size according
to the population within them.
• The spectrum trading units can be
aggregated, and licensees are free
to use whatever device or technology
they wish, provided that they do not
cause unacceptable interference to
other users.
• Spectrum trading is carried out directly between
buyers and sellers, but any trades have to be
registered with the Australian Communications
Authority.
• The ACA publishes this information on its website.
• It has recorded a total of 246 trades since 1998.
However this figure substantially overstates the
volume of trading as it counts each spectrum
trading unit as a separate trade, and includes the
re-assignment of spectrum between related
companies in the same group of companies.
• In reality about 21 separate exchanges of spectrum
have taken place, and only 12 of these have been
between unrelated entities (representing about 140
spectrum trading units).
Guatemala
• Up to 1996, spectrum was issued by the government in a bureaucratic manner, and was
often subject to long delays and corruption. However the Telecommunications Act of
1996 privatised the incumbent operator, set up a new regulatory body, and
revolutionised the approach to spectrum management. A "bottom-up" approach was
adopted by applying the right of "usofructo" to spectrum. In Guatemala usofructo
rights enable the use of a property owned by another person provided that the use
does not destroy or diminish the property itself. The 1996 Act establishes the
concept of "titulos de usofructos de frecuencias" (TUF), a property right which can
be subdivided, aggregated and traded. These last for 15 years, and this period can
be extended on request. The scheme covers television, radio, and communications
frequencies.
• The national regulatory agency, the Superintendencia de Telecomunucaciones (SIT),
maintains a register of spectrum and its allocation via the TUF. Anyone may apply
to the SIT for a frequency, and the SIT is required to respond in three days. If
the SIT does not reject the application (which it can do because of interference or
of reservations for other uses), it publishes a public notice. Interested parties
may then object or file an application for the same spectrum. Any objections must
be adjudicated in ten days. If there are other applications for the spectrum, the
SIT will then hold an auction of the spectrum; if there are not, there is no charge
for the spectrum.
• SIT reported that it received over 13,000 applications for spectrum since 1996, and
it issued over 5,000 TUF to about 1,050 people. Eighty TUF were subject to
auctions. SIT has had to authorise new details on about 25% of TUF, suggesting that
secondary trading is running at this level. As TUF can be used as a security
against loans etc, this may include financial transfers as well as operational
transfers.
New Zealand
• New Zealand became the first country to implement spectrum trading when it started
the scheme in 1989. In order to do this, it created two types of property rights:
• management rights of a defined block of spectrum allow the manager to have use of
the spectrum for up to twenty years and to issue licences for the spectrum; there
are about 80 blocks of spectrum issued to eight bodies (mainly operators and the
government);
• licence rights permit the use of specified spectrum without interference from other
users. Licences may contain conditions of use, but they do not limit use to any
particular technology or application.
• Both rights can be traded, as with any property rights, and can be subject to
mortgages. The Ministry of Economic Development maintains a public record for
spectrum management and licence rights, but does not produce a separate record of
spectrum trading. However it is known that after television spectrum became
tradable in 1995, the operator of the fourth television channel used the system to
acquire sufficient spectrum to launch its service.
• In April 2005 the New Zealand government completed a review of its spectrum
management policy, and noted that the volume of spectrum trades has been low. It
attributed this to the small number of buyers and sellers, and to the ready
availability of unused spectrum. The report raised a number of questions about
whether the spectrum trading system could be made more effective, for example by
permitting geographical subdivision of spectrum management rights or instituting a
"use it or lose it" condition on spectrum management rights and licences.
United States
• In 2003 the Federal Communications Commission (FCC) introduced rules to govern spectrum trading, and
in mid-2004 simplified the scheme. It distinguishes between the transfer of de jure rights (that is,
assignment of the licence to another party) and de facto control (in which the transferee retains the
licence and legal responsibilities, but transfers management control of the spectrum). However
essentially both forms of transfer follow the same process, as follows:
• the spectrum holder and the transferee agree to the transfer;
• both notify the FCC and certify that they satisfy pre-defined public interest criteria (including
conformance with foreign ownership requirements, competition rules etc);
• the FCC gives immediate approval to the application;
• the application is placed on a public register, and interested parties have 30 days in which to
request that the FCC reconsiders its approval (and the FCC itself has 40 days if it wishes to
reconsider the application);
• if the FCC finds that the self-certification was incorrect, it can take enforcement action at any
time.
• The FCC specifically excludes from this process spectrum trading that would result in mobile voice
and data operators aggregating spectrum in their existing areas of operation. These arrangements
cover most spectrum bands, while restrictions are placed on some uses (for example emergency service
providers can only trade with other emergency service providers).
• In 2004 the FCC proposed a new concept to assist with spectrum trading, the "private commons". Its
purpose is to assist the development of smart devices which adjust the spectrum they use to take
advantage of under used spectrum. Holders of spectrum would enable other suppliers to share the
spectrum (the other schemes only permit the transfer of spectrum), but the spectrum holder would
retain the licensing responsibilities. This scheme would be limited to peer to peer devices that do
not use a hierarchical network or the infrastructure provided by the spectrum holder.
• A substantial volume of spectrum is traded in the USA. The FCC publishes all spectrum trades, and
during the first four weeks of June 2005, 186 separate trades were recorded. Of these, 77% were full
assignments of the spectrum to another party, and 10% transfers of de facto control. Most of the full
assignments were between business entities, and most of the de facto control transfers were for
spectrum used for educational television.
• At least one commercial company in the USA has set up an on-line spectrum trading exchange, which
enables buyers and sellers of spectrum to register and trade their interests.
• Forms of Spectrum Trading
• The European Commission identifies the following methods for transferring rights of
use:
• Sale – Ownership of the usage right is transferred to another party;
• Buy-back – A usage right is sold to another party with an agreement that the seller
will buy back the usage right at a fixed point in the future;
• Leasing – The right to exploit the usage right is transferred to another party for
a defined period of time but ownership, including the obligations this imposes,
remains with the original rights holder.
• Mortgage – The usage right is used as collateral for a loan, analogous to taking
out a mortgage on an apartment or house.
• In terms of the trade itself, there are a variety of mechanisms that can be used.
These include:
• Bilateral negotiation: The seller and (prospective) buyer directly negotiate the
terms of the sale and are not subject to any particular constraints set by the
regulator;
• Auctions: Once a type of auction has been chosen and the rules have been decided by
primarily the seller, prospective buyers have the opportunity to acquire the
spectrum usage rights by bidding in the auction;
• Brokerage: Buyers and sellers employ a broker to negotiate, with their consent, the
contractual terms under which the transfer of usage rights can take place;
• Exchange: This refers to the establishment of a commercial trading platform,
similar to a stock market, where transfers take place according to specific rules
established by the members.
• These mechanisms are most likely to be used in combination. In the first instance
an auction will be used as the primary means of assignment, tradable spectrum is
listed on an exchange and either direct negotiation or brokerage facilitate the
transfer of spectrum user rights. As we have discussed earlier band managers may be
delegated responsibility for managing certain bands on behalf of the regulator.
• New Zealand's Radiocommunications Act 1989 was pioneering and radically changed the
landscape of spectrum management. New Zealand was the first country to create a
management rights system whereby owners of blocks of “management rights spectrum”
are free to issue spectrum licences for the specified part of the spectrum
according to their own policies. In New Zealand‟s case, there are 209 management
rights blocks with 70 reserved for the government covering services like broadcast.
The other 139 blocks are reserved for essentially commercial services like fixed
and mobile services.
• Spectrum Licences granted by a manager of a block of management rights spectrum
usually have the following characteristics:
• assigned for a defined period of time;
• non-specific to equipment or transmission methods; and
• define an envelope within which the licence holder is free to operate at his or her
discretion.
• New Zealand's Radiocommunications Act 1989 was pioneering and radically changed the
landscape of spectrum management. New Zealand was the first country to create a
management rights system whereby owners of blocks of “management rights spectrum”
are free to issue spectrum licences for the specified part of the spectrum
according to their own policies. In New Zealand‟s case, there are 209 management
rights blocks with 70 reserved for the government covering services like broadcast.
The other 139 blocks are reserved for essentially commercial services like fixed
and mobile services.
• Spectrum Licences granted by a manager of a block of management rights spectrum
usually have the following characteristics:
• assigned for a defined period of time;
• non-specific to equipment or transmission methods; and
• define an envelope within which the licence holder is free to operate at his or her
discretion.
• Band Managers
• A band manager will typically have assignment rights over, or be the licensee of, a
block of spectrum, which it will then subdivide among many users. In many
respects, a band manager can be thought of as a „wholesaler‟ of spectrum, which it
then „retails‟ to individual users.
• Use of a band manager may simply be a means of reducing transaction costs, if
competitive tendering produces a manager which is more efficient in the relevant
business process than the regulator itself. Band managers can also permit more
efficient use of spectrum by pooling demand. Such policy is effective if:
• individual users have insufficient spectrum to achieve efficient usage, and
• different users of spectrum have demand patterns that peak at different periods.
• New technological developments such as „agile‟ technologies which allow
transmitters and receivers to „hop‟ across frequencies increase the potential role
of band management.
• On the other hand, band managers can become possessive of the spectrum which they
have been awarded to manage, and this can thwart spectrum policy objectives, for
example, when the spectrum regulator wishes to re-allocate the spectrum managed by
the band manager to another purpose.
• OFCOM is currently shifting U.K. spectrum policy towards a flexible system of
spectrum manage ment through the liberalization of spectrum usage rights and
spectrum trading. A gradual approach is being adopted, embracing progressively more
bands and greater flexibility in use but relying on competitive assignment methods.
This progression is exemplified by OFCOM‟s intention to apply service and
technological neutrality in a forthcoming spectrum assignment involving frequencies
currently used to support terrestrial analogue TV broadcasting, the proposed use of
spectrum user rights in a forthcoming auction of the L Band, and in other auctions.
• The United Kingdom has also adopted the policy of extending market methods of
spectrum management to public sector spectrum, giving public sector users the right
to trade or lease their spectrum and the obligation to go into the market place to
acquire additional spectrum. OFCOM is also extending the application of
administrative incentive pricing.
• Administrative Incentive Prices (AIP): are intended to encourage licensees of non-
auctioned spectrum to use their spectrum rights efficiently; legislation enables
annual licence fees to be set above administrative cost to reflect a range of
spectrum management objectives (efficient management and use, economic and other
benefits, innovation and competition), having regard in particular to availability
of present and expected future demand for spectrum. OFCOM has been using AIP since
1998 and revised the approach in 2004. There AIP is used to value spectrum at its
marginal value as a proxy for the opportunity cost to the representative spectrum
user in those bands where AIP fees were charged.
• International experience in spectrum trading was highlighted in the sections above
and the following similarities and differences were exhibited:
• there were few , if any, signs of intermediaries being active in the market;
• there were no signs of speculators entering the market;
• several countries exhibited significant levels of trade (Guatemala and El Salvador)
or a number of significant ($ hundred million) trades (the United States);
• in Australia and New Zealand, levels of trade have been fairly low (roughly equal
to the turnover of commercial property) reflecting an orderly turnover in spectrum
through trades;
• in the United Kingdom, trades in the limited bands available have been infrequent,
but the number of traded bands has been small and the spectrum regulator is in the
middle of a large programme of spectrum awards which may provide an alternative
source of spectrum to those who want it.
• Liquidity of spectrum markets remains a real issue, and the design of
liberalization measures should be in the foreground.