This disclosure describes techniques for optimizing the allocation of physical resource blocks (PRBs) for user equipment (UE), such as a Narrow-Band Internet of Things (NB-IoT) device, within a Long-Term Evolution (LTE) spectrum. More specifically, a resource allocation controller that is configured to select one of at least two resource allocation algorithms that allocate physical resources within an LTE spectrum, based on an identity of the UE and an analysis of real-time or near real-time physical resource utilization and control utilization within the LTE spectrum. In one example, the resource allocation controller may analyze the physical resource utilization and control utilization within a subframe of an LTE spectrum to determine whether to allocate an exact or near-exact number of PRBs for data communications of a UE (i.e. NB-IoT device), or whether to allocate a PRB group (at least four PRBs) for data communications of the UE.