Threading ECCM (6d6.hits(5)=2)
Fading Resistance (12d6.hits(5)=6)... Well that was a ludicrously successful resistance roll.
Alright, Matrix rules dump for everyone's benefit: Jamming basically only effects you if your Signal rating (with, if you have one active, your ECCM program rating added in) is less than the rating of the Jamming. Fionn's Signal is Resonance/2, so 3 (rounded up), and he's just threaded a Rating 2 ECCM Complex Form to help him cut through. So he's only effected by the jamming if the rating thereof at his location (there's falloff due to distance; -1 every five meters from an area jammer or 20 meters from a directional jammer) is 6 or higher. The rules describe a jammed device as "losing wireless connectivity"; plain text, that probably prevents receiving transmissions just as much as sending them, but that's up to Crossbow for a ruling.
Took a quick scan through because I'm trying to be helpful, and it looks like Clem might be okay as well - her Fairlight Caliban has a Signal of 5, so depending on the rating of the jammer there's a decent chance she and Fionn still have comms. The others all have a Signal of 3, so their chances aren't quite as good but depending on the jammer type and positioning there's a possibility.
Long-term, we may want to look at getting (or pirating) ECCM programs for everyone to cope with this exact situation. For the mean-time, I'm just looking to know (a) if Fionn can punch through the jamming, and (b) if so, who if anyone does he see as online?