1. SPECTRUM SHARING IN COGNITIVE RADIO NETWORK
Presentation on
SPECTRUM SHARING IN COGNITIVE RADIO NETWORK
Made By:
NIVEDITA CHANDRAKANT AHIRE

2. AGENDA HISTORY INTRODUCTION DEFINITION COGNITVE RADIO
COGNITIVE RADIO ARCHITECTURE
FUNCTIONALITIES OF CRN
SPECTRUM SHARING IN COGNITIVE RADIO NETWORKS
CLASSIFICATIONS
INTER NETWORK SPECTRUM SHARING
INTRA NETWORK SPECTRUM SHARING
REFERENCES
CONCLUSION

3. HISTORY Proposed by Dr. Joseph Mitola in 1999 YEAR
FEDERAL COMMUNICATION COMMISSION
(FCC)
Dec 2002
Capability of Identifying Idle bands
Nov 2003
Proposed a new performance index i.e. interference temperature
Dec 2003
CR working in group
May 2004
Allow unlicensed radio systems to operate in TV broadcast bands

4. INTRODUCTION 1

5. WHY COGNITIVE RADIO ?
Current wireless networks are regulated by fixed spectrum assignment policy
According to Federal communication commission , temporal and geographical variations in the utilization of the assigned spectral ranges from 15% to 85% .

6. WHY COGNITVE RADIO ? Cognitive radio network :
Fixed Spectrum Assignment policy White Spaces
Inefficient spectrum utilization
Cognitive radio network :
It is a new paradigm that provides the capability to share or use the spectrum in an opportunistic manner.

7. DEFINITION 2

8. COGNITIVE RADIO
Cognitive radio is a wireless communication system which is aware of the environment and its changes and can adapt its transmission parameters accordingly.
Cognitive Capability: The ability to sense the unused spectrum at a specific time and location (spectrum hole)

9. Continued….
Reconfigurability: The ability to receive and transmit at different frequency band enables the cognitive radio to reconfigure its parameters and select the best band.

10. SPECTRUM HOLE

11. COGNITIVE RADIO ARCHITECTURE3

12. COMPONENTS OF CRN PRIMARY NETWORK SECONDARY NETWORK Primary Users:
Primary users have the license to operate in certain spectrum bands
Primary base station:
Controls the access of primary users to spectrum
SECONDARY NETWORK
Secondary Users:
Secondary users have no licensed bands assigned to them.
Secondary base-station:
A fixed infrastructure component with cognitive radio capabilities and provides single hop connection to secondary users.
Spectrum broker :
Scheduling server shares the spectrum resources between different cognitive radio networks.

13. COGNITIVE RADIO ARCHITECTURE

14. NETWORK ACCESS TYPES
CR Network Access: CRs can access their own base station on both licensed and unlicensed spectrum bands
CR Ad Hoc Access: CRs can communicate with other CRs through an ad hoc connection on both licensed and unlicensed spectrum bands.
Primary Network Access : CRs can access primary base station through the licensed bands.

15. FUNCTIONALITY OF CRN
Spectrum Sensing: This function detects spectrum holes and senses the presence of the LU when the CU operates on a licensed band.
Spectrum Management: Based on the availability of the spectrum and other policies, CR user allocates the best available spectrum band.
Spectrum Mobility: CR user shall vacate the spectrum in the presence of any primary user and move to next best available spectrum band
Spectrum Sharing: CR network has to provide a fair and optimal spectrum allocation method among multiple CR users.

16. COGNITIVE RADIO FUNCTIONALITIES

17. FUNCTIONS OF NETWORK LAYER
Physical layer:
spectrum sensing
data reconfigurable transmission based on Software Defined Radio (SDR).
Link Layer :
spectrum analysis
spectrum selection(spectrum adjustment)
spectrum coordination.

18. FUNCTIONS OF NETWORK LAYER
MAC layer:
Obtaining information on channel occupancy.
Performing negotiation among primary users and secondary users for spectrum allocation and also among secondary users for channel sensing and access.
Synchronizing transmission parameters (e.g. channel, time slot) between transmitter and receiver.
Facilitating spectrum trading functions (e.g. spectrum bidding and pricing).

19. APPLICATIONS OF CRN Leased network Cognitive mesh network
Emergency network
Military network

20. SPECTRUM SHARING IN COGNITIVE RADIO NETWORK6

21. SPECTRUM SHARING
Spectrum sharing is the simultaneous usage of a specific radio frequency band in a specific geographical area by a number of independent entities, leveraged through mechanisms other than traditional multiple- and random-access techniques.
The spectrum sharing process consists of five major steps:
Spectrum sensing:detects spectrum holes and senses the presence of the LU when the CU operates on a licensed band.
Spectrum allocation: Allocation of a channel not only depends on spectrum availability but also depends on internal and external policies.

22. SPECTRUM SHARING
Spectrum access: Since there are multiple secondary users trying to access the spectrum, their access should be coordinated to avoid colliding in overlapping portions of the spectrum.
Transmitter-receiver handshake: After deciding a portion of the spectrum, the receiver of this communication should also be indicated.
Spectrum mobility: If the specific portion of the spectrum is needed by a licensed user, the communication needs be continued in another vacant portion.

23. CLASSIFICATION Classification based on Architecture.
1.Centralized Spectrum Sharing.
2.Distributed Spectrum Sharing.
Classification based on access behaviour.
1.Cooperative Spectrum Sharing
2.Non Cooperative Spectrum Sharing
Classification based on access technique.

24. CLASSIFICATION BASED ON ACCESS BEHAVIOUR
Overlay Spectrum Sharing

25. CLASSIFICATION BASED ON ACCESS BEHAVIOUR
Underlay Spectrum Sharing

26. INTER AND INTRA NETWORK

27. INTER NETWORK SPECTRUM SHARING
Centralized Inter-Network Spectrum Sharing

28. INTER NETWORK SPECTRUM SHARING
Distributed Inter-Network Spectrum Sharing

29. INTRA NETWORK SPECTRUM SHARING
1.Centralized Intra-Network Spectrum Sharing

30. INTRA NETWORK SPECTRUM SHARING
2.Distributed Intra-Network Spectrum Sharing

31. CHALLENGES Common Control Channel(CCC) Dynamic Radio Range
Uses spectrum sharing functionalities.
In feasible in xG networks.
Dynamic Radio Range
Radio range changes with operating frequency due to attenuation variation.
Neighbours of a node may change as the operating frequency changes.
Select control channels in the lower portions of the spectrum where the transmission range.
Select data channels in the higher portions of the spectrum.

32. CONCLUSION
Solve the current existing problems in wireless communications
Dynamic spectrum sharing is being used.
Efficient Spectrum sharing.
Spectrum sharing can be performed over licensed or unlicensed bands
Unlicensed bands allow systems/devices to utilize those bands without requiring a spectrum license

33. REFERENCES IEEE Papers:
[1]H. Feizresan and Dr. M. J. Omidi “Spectrum Sharing in Cognitive Radio Networks” (Electrical and Computer Engineering Department, Isfahan University of Technology)
[2]Varaka Uday Kanth, Kolli Ravi Chandra , Rayala Ravi Kumar ,Associate professor, Dept. of ECE KL University “Spectrum Sharing in Cognitive Radio Networks” in (IJETT) - Volume4Issue4- April 2013
[3]Beibei Wang and K. J. Ray Liu “Advances in Cognitive Radio Networks: A Survey” IEEE Journal Of Selected Topics In Signal Processing, Vol. 5, No. 1, Feburary 2011
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34. THANK YOU