In at least one embodiment, a radio access network (RAN) device maintains a proxy mapping table (PMT) of any mobile radios that are currently registered with the RAN via a mobile subscriber unit (MSU). The PMT indicates, for each mobile radio listed in the PMT, the particular MSU via which that particular mobile radio is registered with the RAN. The RAN device receives a first service request for a first mobile radio that is listed in the PMT as being registered with the RAN via a first MSU and, in response to receiving the first service request, makes a determination that an air-interface link is available for communication between the RAN and the first MSU. In response to making the determination, the RAN device communicates the first service request via the available air-interface link to the first MSU for delivery to the first mobile radio.