Network management apparatus for priority channel assignment to acquire available channels in frequency sharing and method thereof

Network management system according to the present invention, the frequency band sharing method in a network management apparatus for assigning a first channel to secure the available channel, the signal strength measuring unit for measuring a received signal strength of the input signal; And the on-channel and adjacent check the connection candidate channels upon a channel available in the above-identified co-channel and adjacent channel candidate channel of a preset frequency-TVBD (TV Band Device) on the basis of the measured received signal strength based on the check of the available channels of the TVBD, and for calculating the available channel decrease the number of the TVBD anticipated by subsequent re-allocated channel channel, assigns the channel need to re-allocation on the basis of available channel decrease the number of the calculated TVBD It includes; a control unit.