A method of operating a light source (100) including a ballast (110) in electrical communication with a lamp (120). The method includes operating the ballast (110) to determine (920) an average lamp power to be applied to the lamp (120) during a data period. The method further includes operating the ballast (110) to generate and communicate (930) a pulse width modulated drive signal to the lamp (120) during the data period, the pulse width modulated drive signal having one of a first waveform and a second waveform for applying the average lamp power to the lamp (120), the first waveform including at least one pulse representative of a first data bit, the second waveform including at least one pulse representative of a second data bit. The method additionally includes operating the lamp (120) to emit (940) a modulated light output in response to a reception of the pulse width modulated drive signal during the data period, the modulated light output being representative of the first data bit in response to the pulse width modulated drive signal having the first waveform, the modulated light output being representative of the second data bit in response to the pulse width modulated drive signal having the second waveform.