This time around the Bangers have no motivation to project such a field, and the Phican system is offline. It was powered by a tiny auxiliary annie-plant which, following the catastrophic damage to the surface installations, auto-rerouted all its output to redundantly powering life-support for a garrison of trapped Phican soldiers. Oh, the irony.
The Ystreban global system, managed as it is by a bureaucracy with more layers than a prize-winning onion, adjusted coverage only very slightly following the explosions at Sanctuariat: the net was tightened over a few lightly-taxed, pork-barrel provinces on the far side of the planet. Thus it is that the Teraport Cage will serve to safely extract everyone in the joint Banger-Tough expedition.
Of course, they will be teraporting onto a P.D. warship engaged in a truly massive battle for the fate of the galaxy, so the use here of the word "safely" may be a tad premature.