One embodiment of the present invention relates to a method for efficient reassignment of a secondary communication channel (having a first priority) within a white space, upon arrival of a conflicting primary user signal (having a second priority higher than the first priority). In particular, the method comprises reassigning a secondary communication channel to unused portions of one or more white spaces remaining after the arrival of one or more primary users. For example, in one embodiment wherein one or more secondary communication channels are operated at contiguous secondary frequency ranges within a white space, a primary/incumbent user may arrive at a frequency range that conflicts with the secondary frequency range and that generates unused frequency portions of the white space(s). The secondary communication channel may be reassigned to the unused frequency portions of the white space (e.g., forming a non-contiguous secondary communication channel, forming a secondary communication channel having a reduced bandwidth).