White space sharing control method, database device, agent device and communication system

A database apparatus comprising:

• an availability determining section that determines availability of white space for each application based on (i) a request for using the white space transmitted from a wireless device, (ii) primary system information representing a channel used by a primary system, and (iii) application-specific priority information representing priority determined for each application of the white space in advance;
• and
• a database information updating section that stores a result of the determination and updates database information storing a use status of the white space for each application.

An agent apparatus comprising:

• an availability determining section that determines availability of white space for each application based on (i) a request for using the white space transmitted from a wireless device, (ii) primary system information representing a channel used by a primary system, and (iii) application-specific priority information representing priority determined for each application of the white space in advance;
• and
• a notifying section that notifies the wireless device of a result of the determination.

(canceled)