"LightSquared has developed equipment
that doesn’t interfere on the GPS frequencies, but GPS signals are so faint that it is difficult to design navigation
receivers that can hear the signals within the narrow band allocated to that service
So, L2 has bought spectrum that is suitable for their purpose, and their eqipment does not interfere with other existing licensed services/users, except, when those other uses have sold equipment which is defective.
Um, yes, I would call all of the equipment in question defective, because it cannot work in the intended manner (with GPS signals) if there is a signal on *other* frequencies which have nothing to do with the GPS system.
I would say that because the existing body of GPS equipment is so valuable, the FCC and ultimately Congress have to let the defective equipment stand, as ordering the replacement of it would probably put most of the industry out of business.
Which leaves the most effective relief as injuctive relief, i.e. Congress would order the FCC to give L2 another block of suitable spectrum, and order the GPS industry to make some cash contribution for damages as well.
Could just be. There are all sorts of legal
obligations here and the courts have not yet had the final word.