An intelligent lighting system may be installed using pre-existing electrical wiring, such as in a construction or retrofit environment. An intelligent lighting controller and an intelligent lighting fixture may be connected via electrical wiring that is configured for transmitting AC power signals. A commissioning signal may be transmitted to the intelligent lighting fixtures via the electrical wiring. In some cases, the intelligent lighting controller modifies portions of the AC power signal to indicate the commissioning signal. The intelligent lighting fixtures may receive the commissioning signal via the electrical wiring. In some cases, each intelligent lighting fixture that is connected to the electrical wiring, such as each intelligent lighting fixture on a lighting circuit in a room, receives the commissioning signal.