CogNet – Architectural foundation for experimental cognitive radio networks

1. CogNet – Architectural foundation for experimental cognitive radio networks Dipankar Raychaudhuri, Joseph B. Evans, Srinivasan Seshan 2011.4.11 Sin-choo Kim sckim@mmlab.snu.ac.kr

2. Contents • Introduction • Architectural foundation • Global control plane • PHY adaptation and network coding • Spectrum coordination protocols • Radio autoconfiguration protocols • Flexible MAC layer • Network layer protocols • Conclusion / 15

3. Introduction • Cognitive (in Webster) • Applying the experience gathered in one place by one being to actions by another being elsewhere • Cognitive network • a network with a cognitive process that can perceive current network conditions, plan, decide, act on those conditions, learn from the consequences of its actions, all while following end-to-end goals / 15

4. Introduction • Cognitive network Network layer MAC layer PHY layer / 15

5. Architectural foundation • Global control plane • PHY adaptation and network coding • Spectrum coordination protocols • Radio autoconfigurationprotocols • Flexible MAC layer • Network layer protocols / 15

6. Global control plane(1/2) • Global control plane • Crosslayer network management overlay • Monitor, configure and adapt the data plane module / 15

7. Global control plane(2/2) • Provided functions • Initial radio bootstrapping • Rebroadcast control packets, providing global awareness to all cognitive radios • Service discovery function • Edge of the service band • Dedicated portion of a TDMA frame / 15

8. PHY adaptation and network coding • Network coding • Collaborate with each other to recombine several input packets into one or several output packets • Main benefits • Throughput improvements • Increased robustness • Require GCP support • Path establishment 2 + 2 = 4 2 + 1 = 3 / 15

9. Spectrum coordination protocols • Agile wideband radio • Transmitters scan and choose their frequency band • Reactive control • Seek equilibrium resource allocation without explicit coordination • Control rate and power • Common spectrum coordination channel(CSCC) • Each node uses beacons containing spectrum usage information • Spectrum server • Coordinated spectrum usages by centralized spectrum server / 15

10. Radio autoconfigurationprotocols • In bootstrapping process, node aware • Network status • Surrounding nodes • To conduct those process • Obtaining PHY parameters, reachability • Negotiate with existing sub-networks for name/service discovery or performance optimization / 15

11. Flexible MAC layer • Dynamically changes MAC protocols • ex) RTS/CTS • Where collision rarely happened, RTS/CTS is overhead • Compatible MAC Protocol • Ensures that a pair of node can communicate directly with each other. • Nodes that are part of the same constellation must use compatible MAC protocols • Independent constellations may make independent optimization decisions / 15

12. Network layer protocols(1/4) • Overlay-based mechanisms • Supernode • Serve as a gateway between local network layers as well as to the future Internet and its IP-based and overlay-based networks. / 15

13. Network layer protocols(2/4) • Naming and service discovery ID / 15

14. Network layer protocols(3/4) • Cross-layer aware routing • Node can obtain information about the application traffic, specified policies, link capabilities and so on • This information will be exposed via GCP • Forwarding incentives in cognitive network • Encourage forwarding others’ packetsin ad hoc network / 15

15. Conclusion • CogNet provides the way to integrate cognitive networks into global Internet • To apply the information collected, CogNet changes three layers PHY, MAC, network layer and make be possible to communicate by using cross-layer / 15

16. Thank you