This the sort of info you were after? (Happy to be corrected here):
Metro is handled via ESTA centre at Tally Ho in Burwood.
Usually when working two up in a vehicle one officer has the pager the other has an XTS5000 portable with SELCALL, when dispatched by ESTA they are paged and SELCALL'd as well as the details going to the MDT in the vehicle. The officers acknowledge on air and all vehicle movements are done via MDT, enroute, onscene, loaded, clear etc.
MICA (Mobile Intensive Car Ambulance) and AGP (Ambulance General Purpose) units are two up, MICA Response and CSO (Clinical Support Officers) work one up. Most of the metro CSO's rotate through the the ESTA call centre and work as the onsite medical clincian (who makes medical related decisions regarding events). There are Team Managers (who manage a number of ambulance branches) and Group Managers who are above Team Managers who you may also hear on air. Some of these may or may not be MICA qualified. Team Managers/Group Managers will take the roll of a Health Commander at multi patient incidents (unless Paul Holman the Operations Manager is responded).
Each physical 'Branch' will have a number of cars running out of it i.e. for example Hoppers Crossing and Werribee both run out of the Werribee branch (there is no Hoppers Crossing branch). Some ambulances respond from Metropolitan Fire Brigade stations (co-located). WX1 is the AV mobile command unit (office on wheels with radios - sent to large incidents/events i.e. Grand Prix. There are also two multi patient emergency support vehicles (ESV1 and ESV2) that carry cache's of medical equipment.
Check out the Ambulance Victoria magazine:
http://www.ambulance.vic.gov.au/Ambulan ... azine.html
And the ambulance Branch map:
http://www.ambulance.vic.gov.au/Media/d ... f88d-0.pdf