The radio station in the briefing is called "W ka..*static*..ay, which could simply be "WK" radio, and states that it is operating out of Io base.
According to the Infantry background there are only two bases on Io (A moon of Jupiter), one is a Collective capital base and mining facility which was on Haemus prime, the other is on the banks of Silpium Mons, and is an abandoned half-completed base, home to squatters, pirates and smugglers. As the radio station seems to be anti-pirate (encouraging the mercs in killing pirates) I think we can safely assume that the radio station is operating out of the collective base.
The moon Io is actually relatively close the the planet Europa, which is also the home of the "European Mercenaries" from in-game, this is likely who the radio presenter is refering too, as the planet Io is rich in valuable resources it is quite probable that the European Mercenaries are attempting to either take control of the Silpium Mons pirate base to establish their presence in the area to futher aid their war effort against Ganymede with the moon's rich resources, or to prevent the pirates from disrupting valuable transports from the moon.
Either way Commander Braceforth of the 21st Hunter Group tells all of his "Freelancer's" to Search and Destroy, which to me, along with the fact that it is a "Hunter" group sounds like they are there to erradicate all pirates from the base, we know that they are being drawn into a space fighter hanger area but we do not know the outcome of the battle.
The song towards the end of the briefing wav is called Falling in Love Again, the version played is by Marlene Dietrich