Before a new mobile network could fail in public, Catapult Communications made it fail in private - one malformed message, simulated base station and overloaded switch at a time.
Under railway tracks, around racetracks and inside livestock sheds, Boldyn builds networks that other businesses use. Its wager: sharing the infrastructure can make difficult connections worth the expense.
Boingo began by making airport Wi-Fi easier to buy. Twenty-five years later, its real product is the invisible layer beneath airports, bases and ballparks - a lesson in moving from a convenient app to infrastructure that is painful to replace.
For a decade, Federated Wireless made crowded radio bands behave like orderly airspace. Its next wager is that physics-aware AI can turn the same towers and frequencies into much more network.