Verizon's Andres Irlando is officially putting AT&T, FirstNet and others in the public safety industry on notice: The interoperability fight is not over. Not by a long shot. "We don't have true interoperability," said Irlando, who is in charge of Verizon's "public sector" business, which includes sales of services to federal, state, public safety and education customers. "It's time for the industry to come together and solve for true interoperability." Specifically, Irlando is calling for interoperability among Verizon, AT&T, FirstNet and others across a number of services that are specific to public-safety customers. Those services include priority and preemption (which ensures public safety users can access a connection amid network congestion); mutual-aid roaming (where public-safety customers would automatically switch to another nearby network if their primary connection is disabled); application interoperability (wherein features and functions specific to public-safety users work across all networks); and push-to-X interoperability (which includes everything from push to talk services to mission-critical video). Such interoperability would build on the interconnected design of telecom networks in general: After all, phone calls and text messages are already interoperable because they can be sent and received regardless of a customer's network provider.