  In this paper, we compare the performances of cooperative and distributed
spectrum sensing in wireless sensor networks. After introducing the basic
problem, we describe two strategies: 1) a cooperative sensing strategy, which
takes advantage of cooperation diversity gain to increase probability of
detection and 2) a distributed sensing strategy, which by passing the results
in an inter-node manner increases energy efficiency and fairness among nodes.
Then, we compare the performances of the strategies in terms of three criteria:
agility, energy efficiency, and robustness against SNR changes, and summarize
the comparison. It shows that: 1) the non-cooperative strategy has the best
fairness of energy consumption, 2) the cooperative strategy leads to the best
agility, and 3) the distributed strategy leads to the lowest energy consumption
and the best robustness against SNR changes.
