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CR (1)


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CR (1)

  1. 1. Cognitive Radio
  2. 2. Presented By :  Mai Ahmed  Asmaa Youssef  Mohamed Hagazy  Taqwaa Mahmoud Cognitive Radio
  3. 3. contents  History and introduction.  Functions of Cognitive Radio.  Architecture of Cognitive Radio.  Applications.  Challenges.
  4. 4.  Cognitive Radio is an enhancement of Software Defined radio (SDR).  SDR is the result of an evolutionary process from purely hardware-based equipment to fully software-based equipment.  The concept of cognitive radio was first proposed by Joseph Mitola III in a seminar at KTH (the Royal Institute of Technology in Stockholm) in 1998.  The concept of cognitive radio published in an article by Mitola and Gerald Q. Maguire, Jr. in 1999.
  5. 5.  Cognitive Radio is defines as a radio or system that senses and is aware of its operational environment and can dynamically and autonomously adjust its radio operating parameter accordingly.  Types of Radio 1. Fixed Radio : set by operators. 2. Adaptive radio: adjust itself to some sort of expected event and it can changed mode of operation saved in its software but cannot learn from experience. 3. Cognitive Radio: can sense their environment and learn how to adapt.
  6. 6.  Cognitive radio learns from experience.  Cognitive Radio deals with situations that are not planned at the initial time of designed  Types of Cognitive Radio: 1. Full cognitive radio: takes into account all parameters that a wireless node or network can be aware of. 2. Spectrum-sensing cognitive radio: is used to detect channels in the radio frequency spectrum.
  7. 7. Two main problems the Cognitive radio solves 1. Spectrum Utilization The proliferation of wireless devices and rapid growth of wireless services continue to strain the limited spectral resource.
  8. 8. Two main problems the Cognitive radio solves 1. Spectrum Utilization (cont) “The only way t solve people’s need to communicate wirelessly is by new technology .you cannot create new spectrum” Dr.Martin Cooper, Past President of Motorola and inventor of cell phone.
  9. 9. Two main problems the Cognitive radio solves 1. Spectrum Utilization (cont)  The Federal Communications Commission (FCC) ruled in November 2008 that unused portions of the RF spectrum (known as white spaces) be made available for public use.  CR can access unused frequencies to extract more wireless band.  CR can uses frequencies and find available bandwidth where other radios can only see static.  CR represents technology solution to increase spectrum capacity and utilization.
  10. 10. Two main problems the Cognitive radio solves 1. Spectrum Utilization (cont)  CR can access unused frequencies to extract more wireless band.  CR can uses frequencies and find available bandwidth where other radios can only see static.  CR represents technology solution to increase spectrum capacity and utilization.
  11. 11. Two main problems the Cognitive radio solves 2. Interoperability:  Make communication between different technologies easily.  Better Spectral efficiency.  Flexible radio functionalities.  Self organizing.
  12. 12. Functions of Cognitive Radio
  13. 13. Functions of Cognitive Radio. Cognitive cycle
  14. 14. Functions of Cognitive Radio. Main Functions  Spectrum sensing.  Spectrum management.  Spectrum mobility.  Spectrum sharing
  15. 15. Functions of Cognitive Radio. Spectrum Sensing  In order to avoid interference the spectrum holes need to be sensed.  Spectrum sensing techniques are divided into three categories  Non-cooperative detection.  Cooperative detection.  Interference based detection.
  16. 16. Functions of Cognitive Radio. Spectrum Sensing  Non-cooperative Detection  cognitive radio acts on its own. The cognitive radio will configure itself according to the signals it can detect and the information with which it is pre -loaded.  Cooperative Detection  Group or network of CR share the sense information they gain. central station will receive reports of signals from a variety of radios in the network and adjust the overall cognitive radio network to suit.
  17. 17. Spectrum Management  Needed to capture the best available spectrum to meet the best available spectrum to meet user communication requirements.  Cognitive radios should decide on the best spectrum to meet the QoS requirements over all available spectrum band.  Management functions classified as:  Spectrum Analysis  Spectrum Decision Functions of Cognitive Radio.
  18. 18. Spectrum Mobility  The process where a cognitive radio user exchanges its frequency of operation.  The target is to use the spectrum in a dynamic manner by allowing the radio terminals to operate in the best available frequency band.  Try to ensure that the data transmission by the unlicensed user can continue in the new spectrum band Functions of Cognitive Radio.
  19. 19. Functions of Cognitive Radio. Spectrum Sharing  Providing the fair spectrum scheduling method  Sharing is a major challenge in open spectrum usage
  20. 20. Architecture of Cognitive Radio
  21. 21. Architecture of Cognitive Radio Cognitive Radio Networks Architecture The basic components of CRNs are the mobile station (MS), base station/access point (BSs/APs) and backbone/core networks. These three basic components compose three kinds of network architectures in CRNs: 1- Network architectures 2- Links in CRN 3- IP Mobility Management in CRN
  22. 22. Architecture of Cognitive Radio 1- Network architectures A- Infrastructure-Based B- Ad-hoc Architecture C- Mesh Architecture
  23. 23. Architecture of Cognitive Radio 1- Infrastructure-Based In the Infrastructure architecture, a MS can only access a BS/AP in the one- hop manner. MSs under the transmission range of the same BS/AP shall communicate with each other through the BS/AP. Communications between different cells are routed through backbone/core networks. The BS/ AP may be able to run one or multiple communication standards/protocols to fulfil different demands from MSs. A cognitive radio terminal can also access various kinds of communication systems through their BS/AP. Infrastructure architecture of a CRN
  24. 24. Architecture of Cognitive Radio 2- Ad-hoc Architecture There is no infrastructure support in ad-hoc architecture. The network is set up on the fly. If a MS recognizes that there are some other MSs nearby and they are connectable through certain communication standards/protocols, they can set up a link and thus form an ad-hoc network. Note that these links between nodes may be set up by different communication technologies. In addition, two cognitive radio terminals can either communicate with each other by using existing communication protocols (e.g., WiFi, Bluetooth) or dynamically using spectrum holes . Ad-hoc architecture of a CRN
  25. 25. Architecture of Cognitive Radio 3- Mesh Architecture This architecture is a combination of the infrastructure and ad-hoc architectures plus enabling the wireless connections between the BSs/APs . This network architecture is similar to the Hybrid Wireless Mesh Networks. the BSs/APs work as wireless routers and form wireless backbones. MSs can either access the BSs/APs directly or use other MSs as multi-hop relay nodes. Some BSs/APs may connect to the wired backbone/core networks and function as gateways. . If the BSs/APs have cognitive radio capabilities, they may use spectrum holes to communicate with each other Mesh architecture of a CRN
  26. 26. Architecture of Cognitive Radio 2- Links in CRN
  27. 27. 3- IP Mobility Management in CRN Architecture of Cognitive Radio
  28. 28. Applications
  29. 29. Applications •Exploding Number of Heterogeneous Networks •Prolific use of wireless means new challenges and opportunities for medical care. Patient monitor networks •Body sensor network •Low rate and low power Wireless Health Care Environments
  30. 30. Applications Smart Medicine container and wireless event detection/notification system
  31. 31. Applications ISM Wireless Network • WLAN , Zigbee ,Bluetooth  • Medium rate and power • 2.4 GHZ and 5 GHZ • Stationary equipement
  32. 32. Applications Low cost backhaul
  33. 33. Applications Agriculture  Irriwise “wireless radio crop monitoring system”  Provide data to help make better decision on when and how long to irrigate  Lateral line water flow data confirm zone runtime and volume  Assists in precision control of irrigation saving water and fertillzer  Higher crop yields mean greater profits
  34. 34. Applications Augmented Reality  Sitelens a mobile augmented reality system for urban design and urban planning site visites  Sitelens creates “situated visualization”that are related to and displayed in their environment  Eg.representation of geocoded oxygen concentration data are overlaid at the site at which the data was recorded.
  35. 35. Applications New Traffic Models  Augmented Reality View  True View
  36. 36. Challenges
  37. 37. Challenges Lots of Challenges
  38. 38. Challenges Software Challenges  Run time reconfiguration needed reprogramming of hardware in real time . Dynamic software architecture .  Validation of software and general testing  Structured and common APIS(Application programming interface )  security
  39. 39. Challenges Hardware Challenges Problems of SDR  Very high performance RF and ADCs High dynamic range - Interference unpredictable - Mitigate hidden nodes Wide bandWidth - Need to find available spectrum - Need to determine contingent spectrum - Antenna performance Antennas -Wide bandwidth -Adaptable High performance computing and memory -Optimization requirements - Low latency
  40. 40. Reference • Cognitive Radio: Technology Survey and Future Research Directions By : José Marinho , CISUC, University of Coimbra ISEC, Polytechnic Institute of Coimbra , Coimbra, Portugal Edmundo Monteiro , CISUC, University of Coimbra ,Coimbra, Portugal