This document discusses cognitive radio sensor networks (CRSN). It defines cognitive radio as a radio that is aware of its surroundings and adapts intelligently. A CRSN allows radios to dynamically tune to different frequencies and protocols based on environmental conditions to improve accessibility, adaptability, scalability, reliability and interconnectivity. The document outlines the CRSN mechanism of sense, analyze, decide and tune in using sensing and reconfigurable antennas. It compares cognitive radios to conventional radios, highlighting cognitive radios' ability to identify unused spectrum and adapt to interference. Benefits of CRSN include meeting FCC regulations and maximizing throughput. Applications of cognitive radio include compact wireless access points.

1. Cognitive Radio Sensor Network
(CRSN)
Prepared by :
Satyaki Mitra
Pranab Sahoo
Avijit Karmakar
Souradeep Hazra

2. Topics to be discussed
1. What is CR Network
2. CR Antennas
3. CR Mechanism
4. CR Network Accessibility, Adaptively, Scalability,
Reliability and Interconnectivity
5. How Cognitive Radio Works
6. Cognitive Radios vs. Conventional Radios
7. Cognitive Radio benefits
8. Application of Cognitive Radio

3. What is CR Network ?
• Cognitive radios have the ability to monitor, sense, and detect
the conditions of their operating environment and dynamically
reconfigure their own characteristics to best match conditions to
transmit and receive on a variety of bands using a variety of
protocols.
• Cognitive radios sense unused times or
frequencies and may decide to transmit on other user’s
band.

4. CONT.
CR can be defined as “…a radio that is aware of
its surroundings and adapts intelligently”.
Cognitive radio networks, like xG’s xMax system,
represent an innovative approach to wireless
engineering in which radios are designed with
an unused level of intelligence

5. Intelligence at all the 7 layers of
the “OSI” model.
CR uses intelligent
signal processing (ISP)
at the physical layer of
a wireless system and
is achieved by
combining ISP with
software defined radio
(SDR)

6. CR Network Mechanism
1.Sense -> Sensing
antenna
2.Analyze
3.Decide
4.Tune in ->
Reconfigurable
antenna

7. Types of CR Antennas
1.Sensing antenna: wide band antenna which continuously
monitors the frequency spectrum for activity
2. Reconfigurable antenna: narrow-band antenna which
dynamically tune to a specific range within the frequency
spectrum to perform data transfer

8. CR Network Improves
Accessibility

9. CR Network Improves Adaptability
When user roams across borders, the device performs self-
adjustment to stay in submission with local radio operations and
emissions regulations.

10. CR Network Improves Interconnectivity
Multi-terminal / Multi-frequency
communication devices.

11. CR Network Improve Scalability
The network can potentially scale to large numbers of users

12. CR Network Improves Reliability
Self-configuring mesh wireless networks avoid failure by re-routing around
node failures or congestion areas

13. How Cognitive Radio Works

14. Cognitive Radio Cycle

15. Cont.
1. Cognitive radios can identify potential impairments to
communication quality in their environment, for example,
interference, path loss, shadowing and multipath fading.
2. They can adjust their transmitting parameters, such as
power output, frequency, and modulation to ensure an
optimized communications experience for users.

16. Cognitive Radios
vs
Conventional Radios
Conventional Radios:
•Operating in interference-free spectrum.
•Unable to dynamically change parameters, channels or
spectrum bands in response to interference.
•View congested radio spectrum as essentially unusable for
communications due to heavy interference.

17. Cognitive Radios
vs
Conventional Radios
Cognitive Radios:
• Function in challenging conditions to quickly identify unused
“gaps” in spectrum that are not being used.
•Find and tune to other spectrum if interference is detected on
the frequencies being used (example - xMax detects and
determines if interference has reached unacceptable
levels up to 33 times a second)

18. Cognitive Radios
vs
Conventional Radios

20. Comparison

21. Cognitive Radio Benefits
►Designed to meet all FCC
►Able to identify “clean” frequencies, and to quickly tune to those
frequencies
►Interference-free operation
►Can adapt dynamically to maximize throughput (and/or range)
►Compact access points (14 simultaneous calls, 6 Mbps raw data rate)
►Easy to engineer and install

22. Application of Cognitive Radio

23. Conclusion
The term Cognitive Radio was first suggested by prof. Joseph
Mitola 1999
controlled by powerful microprocessors which have been
programmed to analyze a number of the radio channel
parameters.
The key feature of a Cognitive Radio is its ability to recognize the
unused parts of spectrum that is licensed to a primary user and
adapt
its communication strategy to use these parts while minimizing
the interference that it generates to the primary user.
Thank You