표 3. | Table 3. 스마트 계약의 함수 종류 및 기능 | Function types and functions of smart contract.

Function	Type	Smart contract role
wikispectra()	Behavior of smart contracts	Purchase available channel information
payToswich()	Coin payment	1 ETH payment when purchasing available channel information
dataTotx()	Sensing data request	Request sensing data from Sensing data sellers
dataTorx()	Provide sensing data	Providing the collected sensing data
data Toch()	Providing available channel information	Providing available channel information to frequency use buyers
withdraw Fund()	Coin reward	Withdraw 1 ETH to sensing data sellers