The Commonwealth of Massachusetts is divided into five separate Emergency Medical Services Regions. Each region is responsible for overseeing the pre-hospital-to-hospital communications system in their particular area and operating a CMED (Centralized Emergency Medical Dispatch) center.
The CMED center acts as the switchboard for ambulances connecting to hospitals throughout the state. The Center plays a major role in resource management and patient distribution in the event of a major incident.
Plymouth CMED provides services for the Southeastern Massachusetts (EMS Region 5). The system services over 40 fire department, municipal and private ambulance services. The cities and towns provided with coverage are located in the Plymouth, Barnstable, Bristol and Norfolk counties.
When an emergency medical technician or paramedic on the scene of an emergency wishes to communicate with a hospital, they contact Plymouth CMED and here's how it works:
An ambulance calls via a two-way radio to Plymouth CMED.
The CMED operator will ascertain the calling unit's identification, hospital of choice and geographic location (location is important because there are four transmission towers used in Region 5, and the closest tower to the requesting ambulance is patched to ensure clear transmissions).
Ambulances advise CMED of a "priority" so multiple patches can be done according to urgency (priority codes are 1 - 4 with 1 reserved for severe injuries... descending down to 4, reserved for minor injuries).
Via a Motorola radio console, the CMED operator connects the ambulance to the hospital by a combination of two-way radio frequencies and dedicated phone circuits. Plymouth CMED controls ambulance traffic to Brockton, Good Samaritan, Jordan, Morton and South Shore Hospital.
The CMED operator will initiate a tone signal that alerts the hospital staff of an incoming call. The staff at the hospital will then communicate with the ambulance and when communications are complete, the CMED operator will unlink the hospital and ambulance.