Yeah I found out, they use the 800mhz inter-op channels as back-up in case the system fails( the ones linked above, thanks btw). As a third back-up they have their old vhf channel.
The dispatcher spelled it out to the units over the radio and she spelled MPSAC..I am sure it is the same but maybe they have it tagged differnet...I am sure this is the first time they have used them.