As part of the Arkansas trauma system, the state purchased and paid for installation of AWIN radios for pretty much all the ambulances in the state that did not already have them, to allow for communication with TraumaCom in Little Rock. Very minor trauma is not required to go through the system, but just what is considered minor is still a bit up in the air. Ambulances are not really required to participate in the system, but there is a substantial amount of money that an ambulance service can get if it does, so as far as I know everyone is or soon will be.
Also, the state is divided into several sections, and each section has rules of its own on what is to be done. I know that one area requires ambulances to go to where TraumaCom says go, while a neighboring section only considers TraumaCom's input as a recommendation, not a requirement.
There is a lot of information on the Arkansas Trauma System on the Arkansas Health Department web site for anyone interested. While it is still a work in progress, I have heard a lot of good things about it, specifically that it has made a huge difference in getting inter-facility transfers approved, cutting down on delays in getting trauma patients moved up to higher levels of care when necessary. There is still a lot of work to do and just how the ambulance side of things will be in the future still remains to be seen, but overall it seems to be a step in the right direction.