1. Dipankar Raychaudhuri, Joseph B. Evans, Srinivasan Seshan 2011.4.11 Sin-choo Kim sckim@mmlab.snu.ac.kr

2.  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 2

3.  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 3

4.  Cognitive network / 15 4 Network layer MAC layer PHY layer

5.  Global control plane  PHY adaptation and network coding  Spectrum coordination protocols  Radio autoconfiguration protocols  Flexible MAC layer  Network layer protocols / 15 5

6.  Global control plane ◦ Cross layer network management overlay ◦ Monitor, configure and adapt the data plane module / 15 6

7.  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 7

8.  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 / 15 8 2 + 2 = 4 2 + 1 = 3

9.  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 9

10.  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 10

11.  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 11

12.  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 12

13.  Naming and service discovery / 15 13 ID

14.  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’ packets in ad hoc network / 15 14

15.  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 15