Fig. 7
From: Reinforcement learning-based dynamic band and channel selection in cognitive radio ad-hoc networks
Band group movement mechanism according to DRE. It is assumed the bandwidth of each channel provided by each band group follows W1 < W2 < W3. The x-axis represents the DRE of each band group. The DRE is low, moderate, and high if it belongs to [0, r1), [r1, r2), and [r2, ∞). If the DRE is low, the selection of the band need to be changed to lower one since the selected band supports too much bandwidth. However, the CH could not change the band in the range of [0, r1) in band group 1 since there is no band to move. If the DRE is high, the selection of the band need to be changed to a higher one since the selected band does not support the DDR. However, the CH could not change the band in the range of [r2, ∞) in band group 3 since there is no band to move. In the range of [r1, r2) in each band group, the system does not need to change the band since the selected band supports adaptive bandwidth. Therefore, the whole DRE region is divided by the region of “Band usage maintenance” and “Band usage change”