Dipankar Raychaudhuri, Joseph B. Evans, Srinivasan Seshan
2011.4.11
Sin-choo Kim
[email protected]
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Introduction
Architectural foundation
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Global control plane
PHY adaptation and network coding
Spectrum coordination protocols
Radio autoconfiguration protocols
Flexible MAC layer
Network layer protocols
Conclusion
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Cognitive (in Webster)
◦ Applying the experience gathered in one place
by one being to actions by another being
elsewhere
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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
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Cognitive network
Network layer
MAC layer
PHY layer
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Global control plane
PHY adaptation and network coding
Spectrum coordination protocols
Radio autoconfiguration protocols
Flexible MAC layer
Network layer protocols
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Global control plane
◦ Cross layer network management overlay
◦ Monitor, configure and adapt the data plane module
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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
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Network coding
◦ Collaborate with each other to recombine several input
packets into one or several output packets
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Main benefits
◦ Throughput improvements
◦ Increased robustness
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2+2=4
Require GCP support
◦ Path establishment
2+1=3
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Agile wideband radio
◦ Transmitters scan and choose their frequency band
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Reactive control
◦ Seek equilibrium resource allocation without explicit coordination
◦ Control rate and power
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Common spectrum coordination channel(CSCC)
◦ Each node uses beacons containing spectrum usage information
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Spectrum server
◦ Coordinated spectrum usages by centralized spectrum server
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In bootstrapping process, node aware
◦ Network status
◦ Surrounding nodes
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To conduct those process
◦ Obtaining PHY parameters, reachability
◦ Negotiate with existing sub-networks for name/service
discovery or performance optimization
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Dynamically changes MAC protocols
◦ ex) RTS/CTS
 Where collision rarely happened, RTS/CTS is overhead
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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
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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.
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Naming and service discovery
ID
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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
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Forwarding incentives in cognitive network
◦ Encourage forwarding others’ packets in ad hoc network
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CogNet provides the way to integrate cognitive
networks into global Internet
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To apply the information collected, CogNet
changes three layers PHY, MAC, network layer
and make be possible to communicate by using
cross-layer
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