There is a logic to using 450MHz more extensively for M2M networks and applications such as PMR (public mobile radio), especially as so many mobile networks are battling for the limited sub-1GHz resources in other parts of the UHF band such as 700MHz.
However, the option has often been ignored in regulatory recommendations regarding UHF, partly because the band is fragmented. For instance, UK watchdog Ofcom concluded in a recent spectrum management strategy document that there is very little interest in using the 450 to 470-MHz frequencies at all (Ofcom removed the work done on this topic from its 2014 report). However, there are PMR and public safety players, in particular, which believe these low frequencies are being unnecessarily sidelined in EU and UK policy.