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| Cooperative Sensing | Stand-alone Sensing |
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Density | Highly dependent on the density of sensing nodes. | N/A |
| Highly dependent on independency of observation. | |
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Heterogeneity Signals | May result in the situation where secondary users | N/A |
| submit different sensing results and conclusions due to | |
| different perceptions of heterogeneity signals. | |
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Communication Overhead | Heavier communication overhead. | N/A |
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Time Sensitivity | Introduce additional delay from collecting sensing results | Able to promptly use available sub-bands once |
| from sensing nodes to making the decision, | identifying the availabilities. |
| resulting staled sensing results. | |
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Spatial Diversity Gain | Achieve spatial diversity gain with certain densities and | Not able to achieve. |
| uncorrelated observations. | |
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Fading Signals | Higher detection sensitivity under proper density. | Able to achieve detection sensitivity by using feature |
| | detection techniques, such as cyclostationary detection, |
| | and covariance-based detection. |
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Coordination | Sensing and access are fully controlled by the | May result in disorderly accesses to the same available |
| central controller. | sub-bands like a swarm of bees. |
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Reliability | Highly depends on the data fusion scheme as well as | Highly depends on sensing techniques. |
| the credibility of sensing nodes. | |
|