A method, a system, and a non-transitory computer-readable memory resource containing instructions for transmitting data are provided. In an example, the method includes providing a header signal having a first optical property. The header signal indicates a start of a packet, and has a minimum period between transitions that is less than a frame period of a receiving device and greater than a scanline period of the receiving device. A payload signal of the packet is provided that has a second optical property that is different from the first optical property. The payload signal has a minimum period between transitions that is less than the frame period of the receiving device and greater than the scanline period of the receiving device.