Thanks to the folks from out of state for trying to help, but the information you posted isn't correct for what the OP requested. The Palmetto 800 talkgroups posted in post #3&4 are the Medtrans Helicopter that flies from GHS (51712) and Greenville County EMS, the public emergency response ambulance service for Greenville County (44065 and 44066).
I suspect a majority of private ambulance services use commercial wireless services, aka "cell phones", for their communications.
There are several UHF DMR frequencies licensed to Communications Service Center in Greenville. These are used mostly by a few Greenville County Fire Departments but also by at least 2 private ambulance services. A couple of us have been trying to nail down their use recently and we've made some progress. I will try to update the database with this information sometime this weekend.
Medshore EMS is another private ambulance service in the Upstate and they do operate on Palmetto 800.
Yeah, I think that gets tricky. There are plenty of counties or other governments that contract with private ambulance services to provide "public" 911/emergency response. Barnwell County SC contracts with Medshore for emergency ambulance service, for example. AMR (American Medical Response) and Rural/Metro are two of the big providers, at least in the southeast.
I think Cherokee County SC recently put out bids to companies to provide emergency medical service after their contract with their local hospital - Upstate Carolina, which was later bought by Mary Black Hospital, which was recently purchased by Spartanburg Regional Medical Center - ran out and was not renewed. In fact, here's a news article from August 2019 saying that Lifeguard Ambulance will soon be providing 911 emergency medical service in Cherokee Co. Cherokee County Council approves new ambulance service I think that Lifeguard might be the service using talkgroup 51733 in the Midlands, that I posted about last week in the OpenHmz.com thread regarding Sumter County.
Many big hospital systems (quasi-private entities now) also provide non-emergency transports that compete with for-profit ambulance services. In the Upstate I see Ambu-star, Transmed, Family Medial and numerous others along with ambulances marked as operated by Spartanburg Regional, though they aren't emergency response ambulances.
The ambulance service (aka Medicare) is obviously a lucrative business to be in.
Just to weigh in a little, I work for one of the private companies. We utilize PTT, and CAD/MDT for dispatching. We are alerted by PTT to an incoming call, and then all further call notes, and or dispatching is done on out MDT. We very rarely have any voice communications on PTT. We do obviously have access to all the Med Channels, as well as 340, but very rarely have to use them. There is some discussion on switching to a radio system, but it would not be in the open in any way.
Thanks BMedcom for your input. I think that most of us tend to focus on emergency code 3 responses and forget how many routine transports between patient's homes, doctors offices, hospitals, and retirement centers go on every day. We had a guy in our rescue squad whose father owned a private service in the 1990's. At that time, they were using the Nextel system to do their dispatching and operations. I asked why not use Pal 800? He said that they had a fair number of transports daily that went well beyond the state line. A lot of them were to VA hospitals. If he had gone to 800, he still would require other communications for these and also secure capabilities for HIPPA compliance when it came in.
Truly the cell phone tower based systems in place with the options for PTT and Data are capable beyond anything imagined back then. Of course, there is the billions (maybe trillions now) of dollars of infrastructure that went into place to make it possible. I always chuckle to myself when the hard core public safety guys remind me how nobody needs backup communications anymore. It is true to a major extent, but it took a lot money to get there.
This isnt for your area, but just to add information, the private ambulance companies down here in Florida tend to have a TG on the main agency system, and then their own trunked UHF DMR system. Ive seen UHF DMR usage among private ambulances in other places also, so that may be a good place to start looking.
They are using some sort of UHF DMR system. It is not the hospitals VHF DMR system used for Police/Security. Most carry UHF XPR3500/XPR7550 some now have the SL series radios. The ambulances have the XPR5550 in them. I am not sure if they are on a wide area commercial service or what but I know they are UHF and while I am at work I try to get info an no one knows.