The FCC has suggested that it will give Public Safety additional spectrum sometime later, why isn’t that good enough?
The fact that the D Block is right next to the Public Safety band allows Public Safety to build one network, double its capacity, solve the interference issue, and allow Public Safety to keep up with advancing tools. Having the two bands combined to serve one network significantly reduces the cost and complexity of the network equipment and devices compared to having the spectrum split across two non-adjacent bands. Additionally, by combining the two bands, Public Safety could utilize the entire 10 MHz where having the D Block separated will necessitate wasting spectrum to carve out a guard band between D Block and Public Safety.