emscom
EMSCOM came about in the 70s as part of federally funded improvements to the EMS system. What is so unique about Az is EMS communications are centrally managed out of DPS. For those systems like the rural areas , to use the med channels you call DPS(EMSCOM) on MED 5 and request a patch to the hospital of your choice. What may people do bnot know is if the need arises to speak to a doctor on the other side of the state by telephone, DPS can do that too. They have the ability to patch maountaintops together. They also can, and have handled areomedical requests for first responders. Busier systems such as flag, Yuma and Phoenix have Standalone systems, Phoenix and Tuscon assign their own channels and yuma has Med-6 permanently assigned to Yuma regional.
There are 31 mountaintops under the control of DPS, one VHF subsystem(navajo county) and Med-5 is in every DPS unit on the road.
And yes EMSCOM has lost its luster to cellular networks and Trunked systems, but when I sopoke to the EMSCOM manager for DPS about its demise, he stated "something", like emscom will continue even if the state migrates to 700mhz in the future. Either the 460 system will remain, or they will upgrade.