Large-scale facilities such as halls are commonly equipped with a plurality of lamps. In many cases, the plurality of lamps are divided in several groups (e.g. two groups), and the lamps in a same group are wired to a common wall switch so that each group of lamps can be turned on or off individually. For example, as shown in FIG. 12, a plurality of lamps may be divided in: a group of lamps wired to a first wall switch X; and a group of lamps wired to a second wall switch Y which is different from the first wall switch X, so that each group of lamps can be turned on or off individually. With this structure, it is possible to turn on a necessary minimum number of lamps from among the plurality of lamps, and to thereby reduce the power consumption. In addition, it is possible to change the brightness of the facility by, for example, turning on only the first wall switch X, or turning on both the first wall switch X and the second wall switch Y.
Meanwhile, there has been a proposal of a lamp that is controllable by a radio signal transmitted by a remote control device (hereinafter “remote control”) (cf. Patent Literature 1). Generally, such a lamp has identification information (ID) assigned after the lamp has been attached to a lighting fixture, for example. After the assignment, the lamp is controlled to be turned on or off by a radio signal output by the remote control to the lamp having the ID. This identification information can be a single number (PAN-ID) shared among a plurality of lamps, or a plurality of numbers assigned one-to-one to a plurality of lamps.