Provided is a device, which is a transmission device that can improve performance, that includes: a light source; and a transmitter that generates a modulated signal based on an input signal and transmits the modulated signal from the light source as visible light by changing a luminance of the light source in accordance with the modulated signal. The transmitter includes, in the modulated signal, a plurality of items of information related to service set identifiers (SSIDs) of a plurality of mutually different access points in a wireless local area network (LAN), and transmits the modulated signal from the light source.