What is a Cognitive Radio

1
What is a Cognitive Radio?
Dr. Paul J. Kolodzy Director, Wireless Network
Security Center Stevens Institute of Technology

• March 15, 2004

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Progression of Radio Terminology

• Radio (from RadioTelegraphy)
• Agile Radio
• Flexible Radio
• Adaptive Radio
• Software Defined Radio
• Software Radio
• Cognitive Radio Aware Radio
• ???????

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What is a Cognitive Radio???

• Cognition
• The act or process of knowing including both
  awareness and judgment
• Awareness
• Having or showing realization , perception, or
  knowledge
• Realize
• To cause to seem real
• Perception
• Awareness of the elements of environment through
  physical experience to become aware through the
  senses
• Knowledge
• The circumstance or condition of apprehending
  truth or fact

• A cognitive radio has the ability to become of
  aware of its environment and forms an opinion
  based upon that information and can act on it!

4
Some Simple Examples

• MAC Protocols NOT a Cognitive Radio
• Directives to modify operational parameters does
  not allow the device to determine the appropriate
  action
• Cordless Phones a Rudimentary Cognitive Radio
• Channel selection via either channel measurements

• A cognitive radio has the flexibility and the
  adaptability to change its operating conditions
  to its environment (either real or perceived)

5
Source of the Awareness?
External Sources
Self Sensing
Environmental Sensors
Channel Probing/ Feedback

• Challenges occur with the methodology in
  obtaining the AWARENESS
• Localized? Regionalized? Centralized?

6
Source of Knowledge?

• Software!
• Deterministic Algorithms
• Stochastic Algorithms
• Non-linear Algorithms

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APPLICATIONS!
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US Spectrum Allocations(Government,
Non-Government, Shared)

• Spectrum from 322-3,100 MHz
• NTIA regulates 22
• FCC regulates 35
• Shared NTIA/FCC regulates 42

3100 MHz
322 MHz
Frequency Agility, Wideband, and Ultra-Wideband
Devices, creates Challenges at the Interfaces
between the Different Allocations --- Aware
Devices create Challenges in the Dynamical
Behavior of the Devices (e.g. interference
avoidance)
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Device Mobility Continues to Rise
Mobility
10
Transceiver Density is Increasing
1-10 Devices per Building
1-10 Devices per Home
1-10 Devices per Person

• Is the tendency to follow a similar trend that
  the computer industry exhibited?
• A few devices that the user interacts with
  directly such as a mainframe or personal computer
  (television, cell phones, amateur radio) to
• A few devices that the user interacts with
  directly and many more devices that are in the
  background performing functions such as
  optimizing performance of automobiles,
  refrigerators, toys, televisions, etc
  (bluetooth, 802.1x, UWB)

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Improving Access - Dynamics
CMRS
Public Safety
Data Services
1
10
100
10
1
Data Services
CMRS
Public Safety
Use of public safety spectrum is highly variable
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The Time Dimension!
Geography
Mobile
SAR
Spread
Tune for Daylight
User 1
User 2
Time
User 3
User 4
User 5
Frequency
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Interference Protection
It doesnt matter what the signal level is here!
Interference Temperature
It matters what the signal level is here!

• Define interference temperature total RF
  energy from both ambient noise and other sources

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ACCESS!
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Outline

• Promises and Challenges in
• Technology
• Security

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Aware Radio Technology
Sense the Environment, Modify Operation to
Adapt to the Environment

• Flexible capable of responding or conforming
  to changing or new situations
• Agile marked by ready ability to move with
  quick easy grace

Dynamics
Flexible Allocations and Use of Frequency Agility
Fundamentally Changes the Manner in Which
Spectrum is Managed
Websters New Collegiate Dictionary
17
Technology for Flexibility

• Software and Software Definable Radios technology
  is becoming available First as emulators

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Technology Challenges for Agility
Power Amplifiers
Filters

• Adaptive RF Components
• Wideband Power Amplifiers
• Broadband Antennas
• Adaptive Filters

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Heterogeneous Access Systems
Smart Agent
Click Router
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Smart Agents and Cognitive Radios
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Secure Access

• Industry concerns about fraudulent use of the
  wireless devices which cause a loss of revenue
• Users concern about privacy
• Digital Rights

• Trusted System Operation
• Authentication
• Authorization
• Integrity
• Privacy
• Non-repudiation

SDR Forums Report on Issues and Activity in the
Area of Security for SDR
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Key Security Aspects

• Environment
• Computational Power ( getting better)
• Bandwidth Limitations ( not getting better)
• BER variability
• Multi-Networks, Multi-Environments
• Mobility vs Nomadic Operation
• Solution Base
• Key Management for Ad Hoc systemss
• Integral Role of Physical Layer
• Address Dynamics in PHY, MAC, and NET

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Summary

• The Technology for Cognitive, Self-Aware,
  Adaptive Radios is Becoming a Reality
• Look at the definitions!
• Pick the Appropriate Applications to Demonstrate
  Capability and Develop Actual Requirements
• Regulating a Self Regulating Device Network
  is a Major Challenge
• Technology for VVA?
• Engaged Process will Help
• Security becomes Increasingly Important as the
  Ability to Impact the RF Environment Increases
• Physical, Access, Network, and Application Layers
  are Intertwined and can be mutually leveraged