Telecommunications Regulation & Trends
Lectures 2-4: Spectrum Management
Fundamentals
Dr. Fadel Digham (‫)فاضل ديغم‬
R&D Executive Director
National Telecom Regulatory Authority (NTRA),
Egypt
Radio Spectrum
The radio spectrum is a
subset of the
electromagnetic waves
lying between the
frequencies from 9 kHz
to 300 GHz.
Source: Ofcom
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• In general, signals sent using the higher
frequencies have lower propagation distances
but a higher data-carrying capacity
Free Space Path Loss
is proportional to d 2 f 2
• These physical characteristics of the spectrum
limit the currently identified range of applications
for which any particular band is suitable.
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Radio Spectrum
• In the past, radio spectrum has been highly regulated to
protect against interference (defense, public interests,
security)
delayed, in some cases, the introduction and growth of
a variety of beneficial technologies and services, or
increased the cost of the same through an artificial
scarcity
• The demand for spectrum has grown significantly
highlighting the need for efficient use of all available
spectrum in order to avoid scarcity
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Key Definitions
 Spectrum Allocation : setting out what radio services
can use which frequency bands and under what
conditions (National Frequency Allocation Table).
 Allocation: distribution of frequencies to radio
services (on a primary or on a secondary basis)
•
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Spectrum Resource Usage: Spectrum is used as an input into a
multitude of services:
- Communications services: narrow or broadband mobile
telecommunications, broadcasting, aeronautical and marine
communications, and communications for public bodies such as
defense or emergency services.
- Non-communication uses: military and civilian radar, scientific
applications such as astronomy and so on.
Key Definitions
 Frequency Allotment : entries of designated channels
in a plan used by one or more identified countries or
geographical areas, for terrestrial or space radio
communication service(s) under specified conditions.
Allotment: distribution of frequencies to
geographical areas or countries
 Frequency Assignment : authorizations given to users
or radio stations to use radio frequencies or radio
frequency channels under specified conditions.
Assignment: distribution of frequencies to users or
radio stations.
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Spectrum Management System
Spectrum management is the overall
process of regulating and administering
the use of the RF spectrum. It is a
combination of
Administrative and technical procedures
to ensure the efficient operation of radio
communication equipment and services in
compliance with certain rules and
etiquettes.
It takes place at two levels: National and International.
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Spectrum Management System
• Granting
users/operators
access to
spectrum
• Granting
equipment access
under certain
conditions
• Allocation of
portions of the
frequency
spectrum to
specified uses
Authorization
• Monitoring of the
use of the radio
spectrum and the
implementation of
measures to control
unauthorized use.
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Monitoring &
Compliance
Planning
Engineering• Development of
electromagnetic
compatibility
standards for
equipment that emits
or is susceptible to
radio frequencies
Spectrum Planning
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Spectrum Planning
It means:
Developing and implementing spectrum management tools,
techniques, and polices to introduce efficient spectrum
utilization.
Why:
• To let the regulators prepare an appropriate response
for the future events.
• To meet the growth in spectrum demand.
• To achieve the social and economic importance of
spectrum use.
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Considerations in planning
Public Benefits
Other Considerations
•Access by radio is easy than wired
•
No national boundaries for radio
waves propagation.
•
Spectrum is available equally in
every country.
•
Radio systems operate on a
world-wide basis.
•
International cooperation is
needed.
•
Radio regulations contain
provisions for all radio services.
•Service reaches with high quality
•Social and economic importance
•Impact of new tech.
Technical
•Compatibility with other services
•Bandwidth required
•Minimum signal strength
•Practical antenna ch/s
•Propagation ch/s
•Acceptable Interference Level
•Receiver complexity, and availability
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Technical Consideration Examples
Types of Communications Duplex
• Simplex Communication: One-way
communication
• Half-duplex Communication: Two-way
communication but not simultaneous
(Push-to-talk)
• Full-duplex Communication: Two-way
communication simultaneously
FDD & TDD
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Technical Consideration Examples
Multiple Access Schemes
power
FDMA/OFDMA
power
TDMA
power
CDMA
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Frequency Allocation
The Spectrum Chart in Egypt
Spectrum Authorization (or Assignment)
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Spectrum Authorization/Assignment
Schemes
Spectrum
Assignment
Schemes
Licensed
Unlicensed
Commons
(Non-Exclusive)
(Non-Exclusive)
Command &
Control
Spectrum
Trading
(Exclusive)
(Non-Exclusive)
Spectrum Authorization/Assignment
Schemes
• Licensed vs. Unlicensed
> Licensed: allocated for fee (auctioning for example as in
the mobile case)
> Unlicensed: free access (as in the WiFi case)
• Exclusive vs. Non-Exclusive use:
> Command and control classical approach: dedicated for
specific users for specific purposes with interference-free
guarantee
> Commons (shared access): common pool of frequencies
> Secondary market (tradable spectrum): a primary
spectrum holder can resell or lease its spectrum to a
secondary operator/user
Licensing Function
Aim: Issuing a licensing to operate a transmitter under
specified conditions will minimize interference
• Examine applications of licenses for eligibility and technical compliance
with equipment standard.
• Grant authorization to use national allocation table
• Issue licenses and collect fees
• Review, renew or cancel licenses
• Ensure the technical parameters mentioned in the license.
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Licensing Function
• Historically, licenses have been awarded in “beauty contest” mode
• Most countries now have adopted market-based approaches such as
auctions
• A spectrum license can be characterized by a tuple:
[ f, R, P, Owner_Id, Use_Type, Dur ]
f : Frequency
R : Region (e.g., local or national)
P : Power
Owner_Id : License Owner Id
Use_Type : Designated Use
Dur:
License Duration
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Spectrum Engineering:
Spectrum Usage Constraints
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EIRP Limit (CCI effect): WLAN Example
Frequency Bands
Suggested Power (EIRP)
2.4 – 2.4835 GHz
Max. (100 mwatt)
Indoor
5.15 – 5.35 GHz
Max.(200 mwatt)
Indoor
5.470 – 5.725 GHz
Max. (200 mwatt)
Indoor
(Security, Interior, Military)
5.725 – 5.850 GHz
Max. (200 mwatt)
Max. (4 watt)
Indoor
Outdoor
Effective Isotropic Radiated Power (EIRP) = Pout (dBm) – Ct (dB) + Gt (dBi)
“the maximum radiated power over all measured angles”
Pout = transmitter power output (dBm)
dBm: 10 log10 (p in mWatt)
Ct = cable attenuation (dB)
Gt = antenna gain (dBi)
dBi: the gain of an antenna system relative to an isotropic
radiator (decibels relative to isotropic)
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Spectral Mask (ACI effect)
WLAN 802.11
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Spectrum Monitoring and Control
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Spectrum monitoring
• Spectrum monitoring serves as the eyes and ears of
the spectrum management process.
• The monitoring system provides a method of verification
and “closes the loop” on the spectrum management
process:
Monitoring supplies information used in determining
compliance with rules and regulation, and provides
statistical information on the technical and operational
nature of spectrum occupancy
• Monitoring the spectrum should be on a continuous basis
(24 hours per day) whether locally, regionally, or globally.
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Spectrum Monitoring
Spectrum Monitoring Goals
The overall goal of spectrum monitoring activities is to
support the proper functioning of the general process of
spectrum management:
• Spectrum efficiency in determining planned and actual
frequency usage and occupancy, assessing availability of
spectrum for future uses.
• Compliance with national spectrum management regulations
to shape and sustain radio environments and user behavior,
maximizing the benefit of the spectrum resource to society.
• Resolution of interference problems for existing and potential
users: help users to avoid incompatible frequency usage
through identification of sources of harmful interference
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Spectrum Management Software
• Spectrum management and monitoring systems may
contain a software to automate data collection,
processing, evaluation, and interference analysis tasks.
• Using software to save spectrum monitoring results in
separate database and correlating this information with
the central database of authorized users.
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Objectives of Spectrum Management
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Objectives of Spectrum Management
• Optimizing usage of the scarce frequency resource.
• Planning utilization of unused spectrum.
• Planning the assignment of the frequency spectrum complying
with international rules.
• Eensuring spectrum access for new services and technologies
• Monitoring the frequency spectrum & Minimize radio
interference
• Frequency Coordination, Registration & Notification.
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Objectives of Spectrum Management
• Optimizing usage of the scarce frequency resource.
• Planning utilization of unused spectrum.
• Planning the assignment of the frequency spectrum complying
with international rules.
• Eensuring spectrum access for new services and technologies
• Monitoring the frequency spectrum & Minimize radio
interference
• Frequency Coordination, Registration & Notification.
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Spectral Efficiency
• Data rate: One radio communication system is more
"spectrum efficient" than another if it conveys the desired
information using less of the spectrum resource
spectral efficiency = Rate / Bandwidth
(bits/sec/Hz)
Or spectral efficiency can be expressed as bits/sec/Hz/m2
• Occupancy: Spectrum efficiency also involves the
arrangement of communication systems within the
spectrum resource. In this broader sense, spectrum is
used inefficiently when systems are not packed together
as tightly as possible in frequency bands (as when
excessive guard bands are used), or when portions of
frequency bands are unused while other bands with
similar physical characteristics are congested.
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Spectral Efficiency
In order to promote spectrum efficiency, spectrum
managers must possess some means of:
• quantifying spectrum use
• evaluating various radio technologies and frequency
selection techniques
• using the collected data through spectrum monitoring
measures of spectrum occupancy and utilization for
purposes of making assignments including the effects of
spectrum reuse and band clearing efforts
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Spectrum Economics
Economic objectives relate to ensuring that spectrum is used in ways
which meet the country’s goals covering the efficient allocation of
resources that spectrum is employed by both private and public sector
organizations in ways which meet the country’s economic growth and
other objectives.
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Spectrum as an Economic Resource
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Economic Dimension
•Spectrum is an input into the services that end-users
(households, firms and public agencies) value
• Need to maximize the value of outputs produced by the
spectrum available
Suppose a given quantity of spectrum is available for use in only two
sectors, mobile communications and commercial broadcasting. How
should it be divided between the two uses? What are the factors?
-The value of the services (users point of view: social): S
- The economic value of the service: E
- The basic amount of spectrum needed: A
Spectrum Value
•Example:
Service 1: Mobile (m)
Service 2: Broadcasting (b)
Total available bandwidth W=20 MHz
Service
Social value (S)
Economic
value (E)
Basic Amount
of spectrum (A)
m
0.5
0.7
10 MHz
b
0.2
0.1
1 MHz
• How to allocate spectrum to each service given idle
situation (no guard bands)?
Spectrum Value
•Example:
Service 1: Mobile (m)
Service 2: Broadcasting (b)
Total available bandwidth W=10 MHz
•
Service
Social value (S)
Economic
value (E)
Basic Amount
of spectrum (A)
m
0.5
0.7
10 MHz
b
0.2
0.1
1 MHz
Case
Total value
10 (m) + 10 (m)
(0.5+0.7)*2=2.4
10 (m) + 10 * 1(b)
(0.5+0.7) + (0.2+0.1)*10=4.2
20 * 1(b)
(0.2+0.1)*20=6
Spectrum Pricing
Market-based approaches such as auctions and spectrum
trading are viewed as superior ways of achieving economic
efficiency in assignment than administered methods (e.g.,
recovering the cost of spectrum management).
In practice, auctions tend to be confined to cases where:
• The spectrum available is in scarce supply;
• Many firms want to acquire a license;
• The service to be provided with the spectrum can be
precisely defined;
• The monetary value of the license is relatively high,
justifying what can be a complex assignment procedure
Common Auction Forms
The English Auction: The English auction is the open ascending price
auction. In one variant of the English auction, the sale is conducted by
an auctioneer who begins by calling out a low price and raises it,
typically in small increments, as long as there are at least two
interested bidders. The auction stops when there is only one interested
bidder.
The Dutch Auction: The Dutch auction is the open descending price
counterpart of the English auction
Common Auction Forms
> Single-round sealed-bid auctions:
The Sealed-Bid First-Price Auction: In this auction form, bidders
submit bids in sealed envelopes; the person submitting the highest bid
wins the object and pays what he bid.
The Sealed-Bid Second-Price Auction: As its name suggests,
once again bidders submit bids in sealed envelopes; the person
submitting the highest bid wins the object but pays not what he bid, but
the second highest bid.
> Multiple-round open auctions
> Pure sequential auction: The bidding stops on one
license before it begins on the next license
> Simultaneous auction: allow for license aggregation