Axa Assurance Maroc - Insurer Innovation Award 2024
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Study of admission and control system in a Centralized Cognitive Radio Network
1. Study of admission and control
system in a Centralized Cognitive
Radio Network
Albert TorrΓ³ Vilert
Master Thesis MASTEAM
2011
2. Introduction
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Project based on work of Nicolas Bolivar from the BCDS 1
group of the Universitat de Girona.
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Proposes a new Centralized Cognitive Radio Network
(CCRN) with distributed control system.
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Study the Cognitive Radio (CR) technology, specifically, the
admission and control system of CCRN proposed.
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Develop a simulator program to study and test the behavior
and performance of the model proposed.
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1
BCDS: Broadband Communications and Distributed Systems
3. Content
1. Cognitive Radio technology
2. Centralized Cognitive Radio Network
3. CCBS β Control System
4. Matlab Program
5. Simulations and results
6. Conclusions and future work
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4. 1. Cognitive Radio technology
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Term initially propose by Joseph Mittola in 1998.
βThe related networks are sufficiently computationally intelligent
about radio resources and related computer-to-computer
communications to detect user communications needs...β
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Provide the maximum efficiency of the spectrum to improve
its utilization using dynamic spectrum access techniques.
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Share the wireless channel with licensed users in
opportunistic manner using spectrum holes.
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5. 1. Cognitive Radio technology
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General scheme of CRN with existing network
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6. 1. Cognitive Radio Technology
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CRU in a CRN must
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Spectrum Sensing β Determine which portions
of the spectrum are available.
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Spectrum Decision β Select the best available
channel
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Spectrum Sharing β Coordinate access to this
channel with other users
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Spectrum Mobility β Vacate the channel when
license user (Primary User) is detected.
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7. Content
1. Cognitive Radio technology
2. Centralized Cognitive Radio Network
3. CCBS β Control System
4. Matlab Program
5. Simulations and results
6. Conclusions and future work
7
10. Content
1. Cognitive Radio technology
2. Centralized Cognitive Radio Network
3. CCBS β Control System
4. Matlab Program
5. Simulations and results
6. Conclusions and future work
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11. 3. CCBS β CRU Control System
ξ CCBS Control Algorithm
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12. 3. CCBS β CRU Control System
ξ CCBS Control Algorithm
ξ Frequency distribution
ξ Control Broadcast Transmission β Frequency beacon.
Bit 1/Bit 2 Process
00 CCBS and CRU coordination for using a channel
01 CRU request to use a channel
10 CCBS announcing availability 12
11 Frequency slot occupied.
13. 3. CCBS β CRU Control System
ξ CCBS β CRU Control Algorithm
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14. 3. CCBS β CRU Control System
ξ CCBS Control Algorithm
ξ Time-based approach: Identify the PU presence.
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15. Content
1. Cognitive Radio technology
2. Centralized Cognitive Radio Network
3. CCBS β Control System
4. Matlab Program
5. Simulations and results
6. Conclusions and future work
15
16. 4. Matlab Program
ξ Core definition
ξ Study and analyze the behavior of the model.
ξ Simulator that models the proposed control
algorithm.
ξ Input variables are PUs and CRUs, with a traffic
distribution.
ξ The results: Graphical behavior, % of CRUs
request completed and spectrum efficiency.
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17. 4. Matlab Program
ξ Global variables
ξ Number of frequency slots.
ξ Number of CRU.
ξ Time duration.
ξ Input variables β Traffic generation
ξ PU definition β PU table
ξ CRU time definition β CRU time table
ξ CRU frequency definition β CRU frequency table
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18. 4. Matlab Program
ξ Traffic generation
ξ Traffic models
Assign frequency slots and time slots to PUs.
Assign CRU requests along the time slots.
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PU table CRU time table
19. 4. Matlab Program
ξ Traffic generation
ξ Traffic models
ξ Random β Random parameter
ξ Custom β User table specification
ξ Distribution
ξ Mean arrival time β Poisson
ξ Mean duration β Negative Exp.
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20. 4. Matlab Program
ξ Traffic generation
ξ CRU frequency models
Models to assign the available frequencies to
CRUs
CRU frequency table
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21. 4. Matlab Program
ξ Traffic generation
ξ CRU frequency models
ξ Random β Random parameter.
ξ Custom β User table specification.
ξ Band model
ξ Number of bands.
ξ Random parameter.
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22. 4. Matlab Program
ξ Control Algorithm
ξ Independent function
ξ Uses PU table, CRU time table and CRU
frequency table.
ξ Assign white spaces with specific strategy.
ξ Result is the spectrum after control algorithm
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25. Content
1. Cognitive Radio technology
2. Centralized Cognitive Radio Network
3. CCBS β Control System
4. Matlab Program
5. Simulations and results
6. Conclusions and future work
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26. 5. Simulations and results
ξ Random model simulation results
ξ Random model behavior results
10 PU, 10 CRUs, 10 time slots 128 PU, 128 CRUs, 100 time slots
PU and CRU Random Parameter 0.5 26
CRU random frequency parameter 0.5
27. 5. Simulations and results
ξ Random model simulation results
ξ Evolution of % CRU request completed results
changing random parameters
128 PU, 128 CRUs, 100 time slots 128 PU, 128 CRUs, 100 time slots
Changing CRU random parameter 27
Changing PU random parameter
Fix CRU random parameter to 0.5 Fix PU random parameter to 0.5
28. 5. Simulations and results
ξ Random model simulation results
ξ Evolution of % CRU request completed and
spectrum efficiency changing the number of CRU.
Percentage of CRU request completed Spectrum efficiency
PU and CRU Random Parameter 0.5 28
CRU random frequency parameter 0.5
29. 5. Simulations and results
ξ Distribution model simulation results
ξ Distribution model behavior results
16 PUs, 16 CRUs, 20 time slots 128 PUs, 128 CRUs, 100 time slots
PU & CRU mean arrival time 0.1 CRU Band model with 8 bands 29
PU & CRU mean duration 8. CRU Random Band 0.3
30. 5. Simulations and results
ξ Distribution model simulation results
ξ Comparison between CRU band frequency model
VS CRU random frequency model.
CRU Band frequency model CRU Random frequency model
PU & CRU mean arrival time 0.1 30
PU & CRU mean duration 8
31. Content
1. Cognitive Radio technology
2. Centralized Cognitive Radio Network
3. CCBS β Control System
4. Matlab Program
5. Simulations and results
6. Conclusions and future work
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32. 6. Conclusions and future work
ξ The basics of Cognitive Radio Networks, which is an
actual under study telecommunications technology
are studied.
ξ Using a simple strategy to share the spectrum
contributes to increase the spectrum efficiency.
ξ 95 % of the CRU requests are completed when the
relation of CRU requests respect to the number PUs
or frequency slots is about 75%.
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33. 6. Conclusions and future work
ξ The cooperation and collaboration between Nicolas
Bolivar PhD thesis work and my project was
amazing.
ξ Very good experience to work in a research BCDS
group.
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34. 6. Conclusions and future work
ξ For a complete analysis model, we need to integrate
the modules that are not contemplated in this project
to the simulator.
ξ The study of the behavior of new types of traffic and
frequency distributions that fits the different
standards currently available.
ξ Introduce new algorithms that allow to queue in
memory the requests and serve these petitions in
different time instants.
ξ Method to sense the spectrum is also needed. 34
35. THANK YOU!
QUESTIONS?
Contact:
Albert TorrΓ³ Vilert
albert.torro@gmail.com
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37. 2. Centralized Cognitive Radio Network
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Information and processing module
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Sense the frequency spectrum. Considered perfectly
and continuously done.
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Digitalize the analog signal from the sensing module.
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Store an array of frequency slots and other information
in to the database.
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Process the data information stored in the database in
the control channel module and communicate with
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transceiver module.
38. 2. Centralized Cognitive Radio Network
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Database module
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Store information used for control and
communication module.
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Main tables:
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Sensing table.
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Communication table.
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39. 2. Centralized Cognitive Radio Network
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Control channel module
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Control the communication between CCBS and
CRUs.
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Frequency division and time division multiplexing
techniques.
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Cognitive Pilot Channels.
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Time slot definition. 39
40. 5. Simulations and results
ξ Distribution model simulation results
ξ Evolution of % CRU request completed changing
the mean arrival time parameter
PU mean arrival time CRU mean arrival time
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