[Scan-DC] Airport Emergency Operations Comms

[Jeff Krauss]

I'm listening now to an aircraft emergency for an arrival at Dulles 
(smoke or fumes in the cockpit).
Airport Fire operations on 3M.
The incident commander talks to Airport Ops 1 on 3M, who then 
evidently talks to the control tower, who then talks to the aircraft 
on an Approach frequency.
What is the communications link between Airport Ops 1 and the 
tower?  Another talkgroup?  Wireline?  Or are they physically co-located?