The so-called wireless communication technology comes in various forms, but it generally boils down to using electromagnetic waves for communication.
For Wizards who can to some extent perceive and influence electric and magnetic fields, using magic to achieve this isn't too difficult, at least sending a simple signal poses no problem.
Considering that the electromagnetic waves produced by the Wizards' current capabilities have a limited transmission distance after attenuation, Lynn utilized one hundred airships patrolling around to create temporary signal stations covering half of the kingdom.
Aboard each airship was a Wizard proficient in Thunder Magic who would receive and then resend the faint electromagnetic signals, relaying the messages to the entire kingdom in a short time.